IPv4 - Knowledge

612: 3880: 1953: 34: 2020:. It provides a vastly increased address space, but also allows improved route aggregation across the Internet, and offers large subnetwork allocations of a minimum of 2 host addresses to end users. However, IPv4 is not directly interoperable with IPv6, so that IPv4-only hosts cannot directly communicate with IPv6-only hosts. With the phase-out of the 3792:(ARP) performs this IP-address-to-hardware-address translation for IPv4. In addition, the reverse correlation is often necessary. For example, unless an address is preconfigured by an administrator, when an IP host is booted or connected to a network it needs to determine its IP address. Protocols for such reverse correlations include 731:, given that it belongs to a class-A network with eight bits for the network mask and 24 bits for the host number. When fewer than four numbers were specified in the address in dotted notation, the last value was treated as an integer of as many bytes as are required to fill out the address to four octets. Thus, the address 2526:

are specified in units of 8 bytes, which is why fragment length must be a multiple of 8. Therefore, the 13-bit field allows a maximum offset of (2 – 1) × 8 = 65,528 bytes, with the header length included (65,528 + 20 = 65,548 bytes), supporting fragmentation of packets exceeding the maximum IP length of 65,535 bytes.

2525:

This field specifies the offset of a particular fragment relative to the beginning of the original unfragmented IP datagram. The fragmentation offset value for the first fragment is always 0. The field is 13 bits wide, so that the offset can be from 0 to 8191 (from (2 – 1) to (2 – 1)). Fragments

1307:

Of the approximately four billion addresses defined in IPv4, about 18 million addresses in three ranges are reserved for use in private networks. Packets addresses in these ranges are not routable in the public Internet; they are ignored by all public routers. Therefore, private hosts cannot directly

2591:

field is used for error checking of the header. When a packet arrives at a router or its destination, the network device calculates the checksum of the header including the checksum field. A value of 0xFFFF is expected. If a different result is obtained, the device discards the packet. Errors in the

2458:

field defines the entire packet size in bytes, including header and data. The minimum size is 20 bytes (header without data) and the maximum is 65,535 bytes. All hosts are required to be able to reassemble datagrams of size up to 576 bytes, but most modern hosts handle much larger packets. Links may

2393:

The IPv4 header is variable in size due to the optional 14th field (options). The IHL field contains the size of the IPv4 header; it has 4 bits that specify the number of 32-bit words in the header. The minimum value for this field is 5, which indicates a length of 5 × 32 bits = 160 bits = 20 bytes.

2660:

by some routers and be blocked. The value in the IHL field must include sufficient extra 32-bit words to hold all options and any padding needed to ensure that the header contains an integral number of 32-bit words. If IHL is greater than 5 (i.e., it is from 6 to 15) it means that the options field

1446:

RFC 3927 defines the special address block 169.254.0.0/16 for link-local addressing. These addresses are only valid on the link (such as a local network segment or point-to-point connection) directly connected to a host that uses them. These addresses are not routable. Like private addresses, these

2473:

This field is an identification field and is primarily used for uniquely identifying the group of fragments of a single IP datagram. Some experimental work has suggested using the ID field for other purposes, such as for adding packet-tracing information to help trace datagrams with spoofed source

771:

networking. The revised system defined five classes. Classes A, B, and C had different bit lengths for network identification. The rest of the address was used as previously to identify a host within a network. Because of the different sizes of fields in different classes, each network class had a

3732:

The receiver identifies matching fragments using the source and destination addresses, the protocol ID, and the identification field. The receiver reassembles the data from fragments with the same ID using both the fragment offset and the more fragments flag. When the receiver receives the last

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bit remains 1 for all the fragments that came with 1 in them and for the last fragment that arrives, it works as usual, that is the MF bit is set to 0 only in the last one. And of course, the Identification field continues to have the same value in all re-fragmented fragments. This way, even if

3251:

The Internet Protocol enables traffic between networks. The design accommodates networks of diverse physical nature; it is independent of the underlying transmission technology used in the link layer. Networks with different hardware usually vary not only in transmission speed, but also in the

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When a router receives a packet, it examines the destination address and determines the outgoing interface to use and that interface's MTU. If the packet size is bigger than the MTU, and the Do not Fragment (DF) bit in the packet's header is set to 0, then the router may fragment the packet.

1960:

In the 1980s, it became apparent that the pool of available IPv4 addresses was depleting at a rate that was not initially anticipated in the original design of the network. The main market forces that accelerated address depletion included the rapidly growing number of Internet users, who

2664:

Since most of the IP options include specifications on how many or which intermediate devices the packet should pass, the IP options are not used for communication over the Internet and IP packets including some of the IP options must be dropped as per IPv4 security assessment

3788:, a network interface can have multiple IP addresses. In order to properly deliver an IP packet to the destination host on a link, hosts and routers need additional mechanisms to make an association between the hardware address of network interfaces and IP addresses. The 3287:

The router divides the packet into fragments. The maximum size of each fragment is the outgoing MTU minus the IP header size (20 bytes minimum; 60 bytes maximum). The router puts each fragment into its own packet, each fragment packet having the following changes:

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It is possible that a packet is fragmented at one router, and that the fragments are further fragmented at another router. For example, a packet of 4,520 bytes, including a 20 bytes IP header is fragmented to two packets on a link with an MTU of 2,500 bytes:

4744:

Special Addresses: In certain contexts, it is useful to have fixed addresses with functional significance rather than as identifiers of specific hosts. When such usage is called for, the address zero is to be interpreted as meaning "this", as in "this

1437:

packets, including their headers containing the private addresses, in a protocol layer during transmission across the public network. Additionally, encapsulated packets may be encrypted for transmission across public networks to secure the data.

2498:

If the DF flag is set, and fragmentation is required to route the packet, then the packet is dropped. This can be used when sending packets to a host that does not have resources to perform reassembly of fragments. It can also be used for

1891:(PtP) link, also called a transit link, is a link that does not have an IP network or subnet number associated with it, but still has an IP address. First introduced in 1993, Phil Karn from Qualcomm is credited as the original designer. 2661:

is present and must be considered. The list of options may be terminated with the option EOOL (End of Options List, 0x00); this is only necessary if the end of the options would not otherwise coincide with the end of the header.

755:

In the original design of IPv4, an IP address was divided into two parts: the network identifier was the most significant octet of the address, and the host identifier was the rest of the address. The latter was also called the

2514:

For unfragmented packets, the MF flag is cleared. For fragmented packets, all fragments except the last have the MF flag set. The last fragment has a non-zero Fragment Offset field, differentiating it from an unfragmented

823:, by contrast. CIDR was designed to permit repartitioning of any address space so that smaller or larger blocks of addresses could be allocated to users. The hierarchical structure created by CIDR is managed by the 2012:

was the first RIR to exhaust its regional pool on 15 April 2011, except for a small amount of address space reserved for the transition technologies to IPv6, which is to be allocated under a restricted policy.

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flag set to 0, it can calculate the size of the original data payload, by multiplying the last fragment's offset by eight and adding the last fragment's data size. In the given example, this calculation was

1863:

are usually known by names, e.g., www.example.com, not primarily by their IP address, which is used for routing and network interface identification. The use of domain names requires translating, called

1514:. IP packets whose source addresses belong to this network should never appear outside a host. Packets received on a non-loopback interface with a loopback source or destination address must be dropped. 2060:

The IPv4 packet header consists of 14 fields, of which 13 are required. The 14th field is optional and aptly named: options. The fields in the header are packed with the most significant byte first (

3703: 1973:

with IP data services. In addition, high-speed Internet access was based on always-on devices. The threat of exhaustion motivated the introduction of a number of remedial technologies, such as:

5807: 1901:. They are used to free IP addresses from a scarce IP address space or to reduce the management of assigning IP and configuration of interfaces. Previously, every link needed to dedicate a 5015: 3360: 3512: 3774: 5792: 588:

model, in that it does not guarantee delivery, nor does it assure proper sequencing or avoidance of duplicate delivery. These aspects, including data integrity, are addressed by an

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network has capacity for just two hosts. These networks are typically used for point-to-point connections. There is no network identifier or broadcast address for these networks.

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By the mid-1990s, NAT was used pervasively in network access provider systems, along with strict usage-based allocation policies at the regional and local Internet registries.

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Since two private networks, e.g., two branch offices, cannot directly interoperate via the public Internet, the two networks must be bridged across the Internet via a

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In the past, conflict between network addresses and broadcast addresses arose because some software used non-standard broadcast addresses with zeros instead of ones.

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In red, is shown the host part of the IP address; the other part is the network prefix. The host gets inverted (logical NOT), but the network prefix remains intact.

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In red, is shown the host part of the IP address; the other part is the network prefix. The host gets inverted (logical NOT), but the network prefix remains intact.

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sends messages with adjusted TTL values and uses these ICMP time exceeded messages to identify the routers traversed by packets from the source to the destination.

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combines the address with its routing prefix in a compact format, in which the address is followed by a slash character (/) and the count of leading consecutive

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publication RFC 791 (September 1981), replacing an earlier definition of January 1980 (RFC 760). In March 1982, the US Department of Defense decided on the

577:, which is the forwarding of packets from a source host to the next router that is one hop closer to the intended destination host on another network. 2004:

The primary address pool of the Internet, maintained by IANA, was exhausted on 3 February 2011, when the last five blocks were allocated to the five

475: 3776:

bytes. When the receiver has all fragments, they can be reassembled in the correct sequence according to the offsets to form the original datagram.

2068:). The most significant bit is numbered 0, so the version field is actually found in the four most significant bits of the first byte, for example. 1447:

addresses cannot be the source or destination of packets traversing the internet. These addresses are primarily used for address autoconfiguration (

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When a packet arrives at a router, the router decreases the TTL field in the header. Consequently, the router must calculate a new header checksum.

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of the ones' complement sum of all 16-bit words in the header. For purposes of computing the checksum, the value of the checksum field is zero.

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2016 IEEE International Conference on Emerging Technologies and Innovative Business Practices for the Transformation of Societies (EmergiTech)

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consists of a header section and a data section. An IP packet has no data checksum or any other footer after the data section. Typically the

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Earlier versions of TCP/IP were a combined specification through TCP/IPv3. With IPv4, the Internet Protocol became a separate specification.

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A three-bit field follows and is used to control or identify fragments. They are (in order, from most significant to least significant):

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As a 4-bit field, the maximum value is 15; this means that the maximum size of the IPv4 header is 15 × 32 bits = 480 bits = 60 bytes.

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The packet payload is not included in the checksum. Its contents are interpreted based on the value of the Protocol header field.

2552:, the router decrements the TTL field by one. When the TTL field hits zero, the router discards the packet and typically sends an 2444:. ECN is an optional feature available when both endpoints support it and effective when also supported by the underlying network. 5082: 3818: 2009: 1014:

between two hosts on a single link when no IP address is otherwise specified, such as would have normally been retrieved from a

534:

address space which provides 4,294,967,296 (2) unique addresses, but large blocks are reserved for special networking purposes.

5749: 4991: 4011: 1868:, them to addresses and vice versa. This is analogous to looking up a phone number in a phone book using the recipient's name. 2544:. It is specified in seconds, but time intervals less than 1 second are rounded up to 1. In practice, the field is used as a 2463:. Fragmentation in IPv4 is performed in either the sending host or in routers. Reassembly is performed at the receiving host. 468: 195: 3897: 3310:

field is set, based on the offset of the fragment in the original data payload. This is measured in units of 8-byte blocks.

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However, this does not mean that every address ending in 0 or 255 cannot be used as a host address. For example, in the

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different capacity for addressing hosts. In addition to the three classes for addressing hosts, Class D was defined for

5238:. Piscataway, NJ: University of Technology, Mauritius, Institute of Electrical and Electronics Engineers. August 2016. 3164: 2397: 397: 340: 265: 5822: 5723: 5243: 3151: 407: 377: 3271:, the next generation of the Internet Protocol, does not allow routers to perform fragmentation; hosts must perform 659:

IPv4 addresses may be represented in any notation expressing a 32-bit integer value. They are most often written in

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The long-term solution to address exhaustion was the 1998 specification of a new version of the Internet Protocol,

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of the Internet Protocol Suite. In essence it forms the Internet. It uses a logical addressing system and performs

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For example, for an MTU of 1,500 bytes and a header size of 20 bytes, the fragment offsets would be multiples of

2380: 2041: 1459: 844: 3476: 1977: 1326: 804: 210: 200: 3891: 1246:

Assigned as MCAST-TEST-NET, documentation and examples (Note that this is part of the above multicast space.)

3741: 3177: 2743:

Indicates the size of the entire option (including this field). This field may not exist for simple options.

2597: 593: 330: 310: 260: 2024:

experimental network starting in 2004, permanent formal deployment of IPv6 commenced in 2006. Completion of

1938:

One of the disadvantages of unnumbered interfaces is that it is harder to do remote testing and management.

1532:. To avoid ambiguity in representation, this address is reserved. The last address has all host bits set to 5045: 760:. This structure permitted a maximum of 256 network identifiers, which was quickly found to be inadequate. 581: 250: 245: 240: 5817: 3789: 3128: 2625: 2574: 2293: 1989: 1309: 427: 387: 255: 4874: 4399: 2005: 1966: 1528:

The first address in a subnet is used to identify the subnet itself. In this address all host bits are

1434: 828: 787:. This division was made more flexible with the introduction of variable-length subnet masks (VLSM) in 3652:

fragments are re-fragmented, the receiver knows they have initially all started from the same packet.

1451:) when a host cannot obtain an IP address from a DHCP server or other internal configuration methods. 5067: 3517:

When forwarded to a link with an MTU of 1,500 bytes, each fragment is fragmented into two fragments:

3253: 2653: 2504: 2029: 1523: 953: 3713:

A receiver knows that a packet is a fragment, if at least one of the following conditions is true:

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contains a complete list of payload protocol types. Some of the common payload protocols include:

2032:

are necessary to permit hosts to participate in the Internet using both versions of the protocol.

5367: 4934: 4174: 3813: 2414: 1947: 1426: 550: 447: 437: 230: 145: 129: 5703: 3784:

IP addresses are not tied in any permanent manner to networking hardware and, indeed, in modern

611: 3190: 2593: 2064:), and for the diagram and discussion, the most significant bits are considered to come first ( 315: 165: 2573:

This field defines the protocol used in the data portion of the IP datagram. IANA maintains a

1113: 848: 616: 442: 215: 5268: 3256:(MTU). When one network wants to transmit datagrams to a network with a smaller MTU, it may 5634: 5556: 5445: 5387: 5329: 5288: 5210: 5128: 4954: 4909: 4853: 4779: 4723: 4674: 4634: 4572: 4511: 4469: 4423: 4373: 4319: 4277: 4215: 4075: 3453:

The total data size is preserved: 2,480 bytes + 2,020 bytes = 4,500 bytes. The offsets are

2588: 2503:, either automatically by the host IP software, or manually using diagnostic tools such as 1993: 808: 763:

To overcome this limit, the most-significant address octet was redefined in 1981 to create

660: 589: 585: 225: 113: 8: 2767:

column is derived from the Copied, Option Class, and Option Number bits as defined above.

2607: 1454:

When the address block was reserved, no standards existed for address autoconfiguration.

1160:

Used for benchmark testing of inter-network communications between two separate subnets

5373:

Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers

4143: 4122: 3934: 3797: 3456: 3272: 2553: 2549: 2500: 2437: 2061: 1923:

subnet using 2 or 4 IP addresses per point-to-point link. When a link is unnumbered, a

1895: 1872: 1854: 1540:

for sending messages to all devices on the subnet simultaneously. For networks of size

1011: 779:

Dividing existing classful networks into subnets began in 1985 with the publication of

499:(IP) as a standalone specification. It is one of the core protocols of standards-based 432: 160: 5777: 5086: 3987: 1875:(DNS), a hierarchical, distributed naming system that allows for the subdelegation of 5548: 5249: 5239: 4699: 4654: 4626: 4564: 4365: 4269: 4067: 3938: 3926: 3918: 2702:

Set to 1 if the options need to be copied into all fragments of a fragmented packet.

2592:

data portion of the packet are handled separately by the encapsulated protocol. Both

2082: 1537: 1463: 1291: 957: 664: 496: 360: 136: 5746: 3879: 5764: 5624: 5538: 5507: 5435: 5377: 5319: 5278: 5200: 5118: 4944: 4899: 4843: 4769: 4713: 4664: 4616: 4554: 4501: 4459: 4413: 4355: 4309: 4259: 4205: 4057: 3942: 3908: 3785: 3644:

Again, the data size is preserved: 1,480 + 1,000 = 2,480, and 1,480 + 540 = 2,020.

3257: 3246: 2666: 2460: 2048:

encapsulates IP packets in frames with a CRC footer that detects most errors, many

1962: 1341: 985: 855:

traffic and to provide addressing space for unrestricted uses on private networks.

796: 788: 780: 708: 554: 520: 5041: 4198:

Y. Rekhter; B. Moskowitz; D. Karrenberg; G. J. de Groot; E. Lear (February 1996).

1755:, broadcast addresses do not necessarily end with 255. For example, a CIDR subnet 1722:

is the network identifier and must not be assigned to an interface. The addresses

5753: 4197: 3838: 2410: 2049: 2025: 644: 508: 500: 301: 55: 5576: 5572: 5559: 5528: 5481: 5477: 5473: 5465: 5461: 5457: 5448: 5429: 5415: 5411: 5407: 5403: 5399: 5390: 5371: 5353: 5349: 5345: 5291: 5272: 5222: 5213: 5194: 5180: 5176: 5172: 5168: 5164: 5160: 5156: 5152: 5148: 5144: 5140: 5131: 5112: 4978: 4974: 4970: 4966: 4957: 4938: 4921: 4912: 4893: 4856: 4837: 4823: 4819: 4815: 4811: 4807: 4803: 4799: 4795: 4791: 4782: 4763: 4686: 4677: 4658: 4637: 4606: 4592: 4588: 4584: 4575: 4544: 4527: 4523: 4514: 4495: 4481: 4472: 4453: 4439: 4435: 4426: 4403: 4385: 4376: 4345: 4322: 4303: 4289: 4280: 4249: 4235: 4231: 4227: 4218: 4199: 4103: 4099: 4095: 4091: 4087: 4078: 4047: 2670: 2540:

field limits a datagram's lifetime to prevent network failure in the event of a

2459:

impose further restrictions on the packet size, in which case datagrams must be

2417:(DiffServ). Real-time data streaming makes use of the DSCP field. An example is 1698:. One can use the following addresses for hosts, even though they end with 255: 800: 792: 5690: 5686: 5682: 5678: 5674: 5670: 5666: 5662: 5658: 5654: 5650: 5646: 5637: 5618: 5590: 5568: 5469: 5341: 5332: 5309: 4739: 4735: 4726: 4707: 3886: 3261: 1952: 1584:

is used to refer to the entire subnet. The broadcast address of the network is

956:

for communications between a service provider and its subscribers when using a

784: 570: 351: 118: 25: 3930: 3655:

The last offset and last data size are used to calculate the total data size:

5812: 5786: 5552: 5253: 5108: 4630: 4568: 4369: 4273: 4071: 3922: 3264:

and is performed in IPv4 routers limiting exposure to these issues by hosts.

2418: 697: 624: 106: 4248:

J. Weil; V. Kuarsingh; C. Donley; C. Liljenstolpe; M. Azinger (April 2012).

3946: 3913: 4605:

S. Venaas; R. Parekh; G. Van de Velde; T. Chown; M. Eubanks (August 2012).

4247: 2639: 2621: 2541: 2537: 1224: 566: 270: 5512: 5495: 5068:"Five /8s allocated to RIRs – no unallocated IPv4 unicast /8s remain" 3303:(MF) flag is set for all fragments except the last one, which is set to 0. 4604: 3863: 2441: 1970: 691: 3963: 5614: 5305: 5080: 4759: 4703: 2508: 2045: 1871:

The translation between addresses and domain names is performed by the

605: 418: 5769: 4835: 5629: 5543: 5440: 5382: 5324: 5283: 5205: 5123: 4949: 4904: 4848: 4774: 4718: 4669: 4621: 4559: 4506: 4464: 4418: 4360: 4314: 4264: 4210: 4062: 3203: 2545: 1876: 1483: 1455: 1430: 852: 773: 672: 648: 647:(2 + 2 + 2 ≈ 18 million addresses) and 101: 615:

Decomposition of the quad-dotted IPv4 address representation to its

5778:

Official current state of IPv4/8 allocations, as maintained by IANA

3859: 3855: 3842: 2754:

Option-specific data. This field may not exist for simple options.

2383:

is the four-bit version field. For IPv4, this is always equal to 4.

1928: 1898: 1860: 1511: 1448: 712: 504: 5365: 2676:

The possible options that can be put in the header are as follows:

5311:

INTERNET PROTOCOL - DARPA INTERNET PROGRAM PROTOCOL SPECIFICATION

4168:"Understanding IP Addressing: Everything You Ever Wanted To Know" 4046:

M. Cotton; L. Vegoda; B. Haberman (April 2013). R. Bonica (ed.).

1927:

is used, a single IP address borrowed from a defined (normally a

1462:(APIPA), which was deployed on millions of machines and became a 1063: 835:

database that provides information about IP address assignments.

687: 668: 516: 33: 2673:, since they can expose the network topology or network details. 511:

networks. IPv4 was the first version deployed for production on

5427: 4118:"Vint Cerf - We Still Have 80 Per Cent of the World to Connect" 2455: 565:

The Internet Protocol is the protocol that defines and enables

531: 512: 381: 275: 174: 154: 5808:

Knowledge articles published in peer-reviewed literature (J2W)

4836:

A. Retana; R. White; V. Fuller; D. McPherson (December 2000).

5274:

Technical Criteria for Choosing IP The Next Generation (IPng)

4660:

Assigned Numbers: RFC 1700 is Replaced by an On-line Database

4301: 4045: 3728:

is nonzero, which is true for all fragments except the first.

2624:

of the sender of the packet. It may be changed in transit by

2021: 832: 776:

addressing and Class E was reserved for future applications.

678:

For example, the quad-dotted IP address in the illustration (

402: 180: 66: 5431:

The Addition of Explicit Congestion Notification (ECN) to IP

2028:

is expected to take considerable time, so that intermediate

5534: 5315: 4550: 4053: 3884:

This article was adapted from the following source under a

3801: 3268: 2065: 2017: 1467: 1109: 1105: 1015: 851:

for special purposes. Notably these addresses are used for

546: 524: 370: 335: 285: 205: 170: 94: 4542: 4343: 5081:

Asia-Pacific Network Information Centre (15 April 2011).

4992:"Understanding and Configuring the ip unnumbered Command" 4497:

Benchmarking Methodology for Network Interconnect Devices

2642:

of the receiver of the packet. It may be affected by NAT.

2104: 847:(IETF) and IANA have restricted from general use various 190: 5793:

Knowledge articles published in peer-reviewed literature

5693:.Obsoletes IENs: 127, 117, 93. 3721:

is set, which is true for all fragments except the last.

3260:

its datagrams. In IPv4, this function was placed at the

2763:

The table below shows the defined options for IPv4. The

5740: 4765:

Requirements for Internet Hosts -- Communication Layers

1138:

Used for local communications within a private network

1043:

Used for local communications within a private network

928:

Used for local communications within a private network

5798:

Knowledge articles published in WikiJournal of Science

5428:

K. Ramakrishnan; S. Floyd; D. Black (September 2001).

4546:

IANA Guidelines for IPv4 Multicast Address Assignments

707:

Other address representations were in common use when

4873:

Almquist, Philip; Kastenholz, Frank (December 1993).

4405:

Deprecating the Anycast Prefix for 6to4 Relay Routers

3744: 3661: 3479: 3459: 3327: 2421:(VoIP), which is used for interactive voice services. 1551:

or larger, the broadcast address always ends in 255.

807:(CIDR), which expressed the number of bits (from the 5065: 4698: 4493: 1961:

increasingly used mobile computing devices, such as

5266: 5107: 3698:{\displaystyle 495\times 8+540=3{,}960+540=4{,}500} 1198:Assigned as TEST-NET-3, documentation and examples 1179:Assigned as TEST-NET-2, documentation and examples 1085:Assigned as TEST-NET-1, documentation and examples 4892:P. Almquist (November 1994). F. Kastenholz (ed.). 4872: 4839:Using 31-Bit Prefixes on IPv4 Point-to-Point Links 4305:Dynamic Configuration of IPv4 Link-Local Addresses 4251:IANA-Reserved IPv4 Prefix for Shared Address Space 3768: 3697: 3506: 3465: 3354: 2052:carried by IP also have their own error checking. 1517: 1472:Dynamic Configuration of IPv4 Link-Local Addresses 5756:— IP Header Breakdown, including specific options 5114:Internet Protocol, Version 6 (IPv6) Specification 2600:have separate checksums that apply to their data. 1271:Reserved for future use (former Class E network) 831:(RIRs). Each RIR maintains a publicly searchable 651:addresses (2 ≈ 268 million addresses). 5784: 5335:. IEN 128, 123, 111, 80, 54, 44, 41, 28, 26. 5196:6bone (IPv6 Testing Address Allocation) Phaseout 5192: 5039: 3898:"A Survey on Internet Protocol version 4 (IPv4)" 1986:removed the need for addresses on transit links. 1738:, etc., may be assigned, despite ending with 0. 1470:defined a formal standard in RFC 3927, entitled 519:in January 1983. It is still used to route most 5724:"Internet Protocol Version 4 (IPv4) Parameters" 5267:Partridge, C.; Kastenholz, F. (December 1994). 4344:J. Arkko; M. Cotton; L. Vegoda (January 2010). 3240: 4347:IPv4 Address Blocks Reserved for Documentation 4302:S. Cheshire; B. Aboba; E. Guttman (May 2005). 3896:Michel Bakni; Sandra Hanbo (9 December 2022). 2474:addresses, but any such use is now prohibited. 1308:communicate with public networks, but require 5040:Smith, Lucie; Lipner, Ian (3 February 2011). 4543:M. Cotton; L. Vegoda; D. Meyer (March 2010). 2436:This field allows end-to-end notification of 469: 5496:"Practical network support for IP traceback" 4012:"IANA IPv4 Special-Purpose Address Registry" 623:IPv4 uses 32-bit addresses which limits the 545:Internet Protocol version 4 is described in 5016:"World 'running out of Internet addresses'" 4891: 4653: 3841:joke, proposed for use in RFC 3514 as the " 3355:{\displaystyle {\frac {1{,}500-20}{8}}=185} 2658:some options may be considered as dangerous 1941: 1674:, which is equivalent to the address range 523:today, even with the ongoing deployment of 5530:Updated Specification of the IPv4 ID Field 5083:"APNIC IPv4 Address Pool Reaches Final /8" 5042:"Free Pool of IPv4 Address Space Depleted" 4754: 4752: 4538: 4536: 4451: 4339: 4337: 4335: 3507:{\displaystyle {\frac {0+2{,}480}{8}}=310} 767:, in a system which later became known as 704:bits in the routing prefix (subnet mask). 654: 553:(TCP/IP) as the standard for all military 476: 462: 5768: 5628: 5613: 5542: 5511: 5500:ACM SIGCOMM Computer Communication Review 5439: 5381: 5323: 5304: 5282: 5204: 5122: 4948: 4903: 4847: 4773: 4758: 4717: 4668: 4620: 4558: 4505: 4463: 4417: 4359: 4313: 4263: 4209: 4193: 4191: 4189: 4187: 4061: 4041: 4039: 4037: 4035: 4033: 4031: 3912: 1983: 667:of the address expressed individually in 643:IPv4 reserves special address blocks for 5588: 5526: 4933: 4455:An Anycast Prefix for 6to4 Relay Routers 4397: 4201:Address Allocation for Private Internets 2330: 1951: 1441: 838: 819:, and the class-based scheme was dubbed 610: 604:For broader coverage of this topic, see 5520: 5421: 5359: 5186: 5101: 4927: 4885: 4829: 4749: 4647: 4598: 4533: 4487: 4445: 4391: 4332: 4295: 3819:List of assigned /8 IPv4 address blocks 3769:{\displaystyle 495\times 8+540=4{,}500} 1882: 1417:Contiguous range of 256 Class C blocks 1312:at a routing gateway for this purpose. 16:Fourth version of the Internet Protocol 5785: 5607: 5493: 5298: 4241: 4184: 4028: 3779: 2656:is not often used. Packets containing 2343: 1395:Contiguous range of 16 Class B blocks 795:in 1987. In 1993, based on this work, 4940:Requirements for IP Version 4 Routers 4875:"Towards Requirements for IP Routers" 4608:Multicast Addresses for Documentation 4494:S. Bradner; J. McQuaid (March 1999). 4049:Special-Purpose IP Address Registries 2713:A general options category. 0 is for 1848: 1466:. Many years later, in May 2005, the 1318:Reserved private IPv4 network ranges 3230:Stream Control Transmission Protocol 2300: 2271: 1935:can be used on multiple interfaces. 1894:The purpose of a transit link is to 5741:Internet Assigned Numbers Authority 4895:Towards Requirements for IP Routers 3858:networking technologies, including 3794:Dynamic Host Configuration Protocol 2315: 2257: 2035: 1980:(CIDR), for smaller ISP allocations 1302: 825:Internet Assigned Numbers Authority 13: 5277:. p. 26. sec. 6.2. 3165:Internet Group Management Protocol 2398:Differentiated Services Code Point 14: 5839: 5803:Externally peer reviewed articles 5734: 5193:R. Fink; R. Hinden (March 2004). 4692: 4115: 3956: 3152:Internet Control Message Protocol 2776:Option Type (decimal/hexadecimal) 2606:The checksum field is the 16-bit 2242: 1458:created an implementation called 5591:"Fragment Offset - IP With Ease" 3878: 3278: 2548:—when the datagram arrives at a 2425:Explicit Congestion Notification 2379:The first header field in an IP 1956:IPv4 address exhaustion timeline 903:Current (local, "this") network 711:was practiced. For example, the 592:transport protocol, such as the 32: 5716: 5696: 5589:Bhardwaj, Rashmi (2020-06-04). 5582: 5487: 5260: 5228: 5074: 5059: 5033: 5008: 4984: 4879:Internet Engineering Task Force 4866: 4613:Internet Engineering Task Force 4410:Internet Engineering Task Force 4352:Internet Engineering Task Force 4256:Internet Engineering Task Force 3848: 3831: 3362:(0, 185, 370, 555, 740, etc.). 1992:(NAT) removed the need for the 1814:11001011.00000000.01110001.0001 1798:11001011.00000000.01110001.0001 1518:First and last subnet addresses 1460:Automatic Private IP Addressing 845:Internet Engineering Task Force 4160: 4136: 4109: 4004: 3980: 2969:Commercial IP Security Option 2487:bit 0: Reserved; must be zero. 1978:Classless Inter-Domain Routing 805:Classless Inter-Domain Routing 495:) is the first version of the 1: 5111:; R. Hinden (December 1998). 3873: 3708: 3178:Transmission Control Protocol 3057:Selective Directed Broadcast 1406:192.168.0.0 – 192.168.255.255 750: 599: 594:Transmission Control Protocol 5761:IP Mobility Support for IPv4 5370:; D. Black (December 1998). 5046:Number Resource Organization 3862:, the hardware address is a 3241:Fragmentation and reassembly 3002:Experimental Access Control 2413:(ToS), this field specifies 2388:Internet Header Length (IHL) 2345: 2214: 1168:198.51.100.0–198.51.100.255 1124:192.168.0.0–192.168.255.255 1104:Reserved. Formerly used for 996:169.254.0.0–169.254.255.255 829:regional Internet registries 690:number 2886794753, which in 584:protocol, and operates on a 7: 3807: 3800:(BOOTP) and, infrequently, 3790:Address Resolution Protocol 3296:field is the fragment size. 3129:List of IP protocol numbers 3024:Extended Internet Protocol 2626:network address translation 2575:list of IP protocol numbers 1990:Network address translation 1967:personal digital assistants 1690:, the broadcast address is 1629:11000000.10101000.00000101. 1613:11000000.10101000.00000101. 1554:For example, in the subnet 1477: 1408: 1383: 1381:172.16.0.0 – 172.31.255.255 1358: 1310:network address translation 1281: 1256: 1237: 1208: 1189: 1170: 1148: 1126: 1095: 1076: 1062:IETF Protocol Assignments, 1053: 1028: 998: 969: 938: 936:100.64.0.0–100.127.255.255 913: 888: 525:Internet Protocol version 6 489:Internet Protocol version 4 78:; 43 years ago 20:Internet Protocol version 4 10: 5844: 5579:. 5527:J. Touch (February 2013). 5484:. 5418:. 5356:. 5225:. 5183:. 5066:ICANN,nanog mailing list. 4981:. 4924:. 4826:. 4689:. 4595:. 4530:. 4484:. 4442:. 4388:. 4292:. 4238:. 4106:. 3275:before sending datagrams. 3244: 3101:Experimental Flow Control 3079:Upstream Multicast Packet 2958:Extended Security (RIPSO) 2493:bit 2: More Fragments (MF) 2490:bit 1: Don't Fragment (DF) 2409:Originally defined as the 2328: 2313: 2298: 2269: 2264: 2255: 2240: 1945: 1852: 1769:has the broadcast address 1521: 1481: 1290:Reserved for the "limited 1254:240.0.0.0–255.255.255.254 1235:233.252.0.0–233.252.0.255 1206:224.0.0.0–239.255.255.255 1187:203.0.113.0–203.0.113.255 1146:198.18.0.0–198.19.255.255 1093:192.88.99.0–192.88.99.255 1026:172.16.0.0–172.31.255.255 967:127.0.0.0–127.255.255.255 603: 560: 537: 5623:. Network Working Group. 5434:. Network Working Group. 5376:. Network Working Group. 5199:. Network Working Group. 5117:. Network Working Group. 4943:. Network Working Group. 4898:. Network Working Group. 4842:. Network Working Group. 4768:. Network Working Group. 4712:. Network Working Group. 4663:. Network Working Group. 4500:. Network Working Group. 4458:. Network Working Group. 4308:. Network Working Group. 4204:. Network Working Group. 4144:"A Brief History of IPv4" 3254:maximum transmission unit 3112:RFC3692-style Experiment 3090:RFC3692-style Experiment 2925:RFC3692-style Experiment 2892:RFC3692-style Experiment 2837:Experimental Measurement 2719:debugging and measurement 2638:This 32-bit field is the 2620:This 32-bit field is the 2291: 2284: 2262: 2233: 2228: 2226: 2219: 2212: 2095: 2092: 2089: 2086: 2055: 2050:transport-layer protocols 1825: 1744:In networks smaller than 1640: 1524:IPv4 subnetting reference 1356:10.0.0.0 – 10.255.255.255 1227:(former Class D network) 671:numbers and separated by 663:, which consists of four 112: 100: 90: 72: 62: 51: 43: 31: 24: 5823:Internet layer protocols 5308:, ed. (September 1981). 5269:"6.2 IP Header Checksum" 4452:C. Huitema (June 2001). 3824: 3733:fragment, which has the 3217:Open Shortest Path First 2721:. 1 and 3 are reserved. 2286: 2235: 2221: 1942:Address space exhaustion 1536:. It is used as a local 911:10.0.0.0–10.255.255.255 723:was commonly written as 686:) represents the 32-bit 5828:Network layer protocols 5494:Savage, Stefan (2000). 3814:History of the Internet 3647:Also in this case, the 3120: 3013:IMI Traffic Descriptor 2415:differentiated services 2030:transition technologies 1948:IPv4 address exhaustion 1427:virtual private network 861:Special address blocks 655:Address representations 551:Internet Protocol Suite 527:(IPv6), its successor. 130:Internet protocol suite 5704:"Cisco unofficial FAQ" 5645:Obsoleted by RFC 5472:. Updated by RFC 5406:. Updated by RFC 5366:K. Nichols; S. Blake; 5344:. Updated by RFC 5147:. Updated by RFC 5139:Obsoleted by RFC 4973:. Updated by RFC 4920:Obsoleted by RFC 4762:, ed. (October 1989). 4734:Obsoleted by RFC 4657:, ed. (January 2002). 4480:Obsoleted by RFC 4432:Best Current Practice. 4234:. Updated by RFC 4173:. 3Com. Archived from 4102:. Updated by RFC 3964:"BGP Analysis Reports" 3905:WikiJournal of Science 3770: 3699: 3508: 3467: 3356: 3191:User Datagram Protocol 2717:options, and 2 is for 2556:message to the sender. 1957: 1931:) interface. The same 1879:to other DNS servers. 1294:" destination address 1074:192.0.2.0–192.0.2.255 1051:192.0.0.0–192.0.0.255 886:0.0.0.0–0.255.255.255 694:format is 0xAC10FE01. 620: 5747:IP, Internet Protocol 5649:. Obsoletes RFC 5513:10.1145/347057.347560 5143:. Obsoletes RFC 4738:. Obsoletes RFC 4581:Best Common Practice. 4522:Updated by: RFC 4398:O. Troan (May 2015). 4286:Best Common Practice. 4224:Best Common Practice. 4084:Best Common Practice. 3914:10.15347/WJS/2022.002 3771: 3700: 3509: 3468: 3357: 3068:Dynamic Packet State 2732:Specifies an option. 1984:Unnumbered interfaces 1955: 1834:As a special case, a 1789:Dot-decimal notation 1604:Dot-decimal notation 1442:Link-local addressing 1157:Private network 1059:Private network 1040:Private network 950:Private network 925:Private network 849:reserved IP addresses 839:Special-use addresses 614: 5338:Internet Standard 5. 4790:Updated by RFC 4788:Internet Standard 3. 3742: 3659: 3477: 3457: 3325: 3317:field is recomputed. 2991:Strict Source Route 2589:IPv4 header checksum 1994:end-to-end principle 1883:Unnumbered interface 1488:The class A network 1012:link-local addresses 954:Shared address space 872:Number of addresses 811:) as, for instance, 661:dot-decimal notation 586:best-effort delivery 5460:. Updates RFC 5456:Obsoletes RFC 5398:Obsoletes RFC 5340:Obsoletes RFC 5221:Obsoletes RFC 4965:Obsoletes RFC 4937:, ed. (June 1995). 4685:Obsoletes RFC 4591:. Updates RFC 4583:Obsoletes RFC 4434:Obsoletes RFC 4226:Obsoletes RFC 4086:Obsoletes RFC 3780:Assistive protocols 2947:Loose Source Route 2815:Security (defunct) 2793:End of Option List 2633:Destination address 2331:Destination address 2073: 2072:IPv4 header format 2066:MSB 0 bit numbering 1496:(classless network 1319: 1276:255.255.255.255/32 862: 709:classful networking 555:computer networking 515:in 1982 and on the 21: 5818:Internet Standards 5752:2011-05-14 at the 5617:(September 1981). 5565:Proposed Standard. 5454:Proposed Standard. 5396:Proposed Standard. 4963:Proposed Standard. 4862:Proposed Standard. 4328:Proposed Standard. 4123:The New York Times 3798:Bootstrap Protocol 3766: 3695: 3504: 3463: 3352: 3273:Path MTU Discovery 3204:IPv6 encapsulation 3035:Address Extension 2554:ICMP time exceeded 2531:Time to live (TTL) 2501:path MTU discovery 2438:network congestion 2071: 2062:network byte order 1958: 1873:Domain Name System 1855:Domain Name System 1849:Address resolution 1810:Broadcast address 1625:Broadcast address 1510:) is reserved for 1317: 988:to the local host 986:loopback addresses 860: 621: 19: 5567:Updates RFC 4384:Updates RFC 4288:Updates RFC 4180:on June 16, 2001. 4148:IPv4 Market Group 3786:operating systems 3642: 3641: 3558: 3544: 3537: 3530: 3496: 3466:{\displaystyle 0} 3451: 3450: 3407: 3393: 3386: 3379: 3344: 3238: 3237: 3116: 3115: 2936:Security (RIPSO) 2758: 2757: 2369: 2368: 1832: 1831: 1828: 1647: 1646: 1643: 1576:) the identifier 1538:broadcast address 1464:de facto standard 1421: 1420: 1298: 1297: 958:carrier-grade NAT 739:is equivalent to 497:Internet Protocol 486: 485: 137:Application layer 124: 123: 5835: 5774: 5772: 5728: 5727: 5720: 5714: 5713: 5711: 5710: 5700: 5694: 5641: 5632: 5630:10.17487/RFC0790 5620:ASSIGNED NUMBERS 5611: 5605: 5604: 5602: 5601: 5586: 5580: 5563: 5546: 5544:10.17487/RFC6864 5524: 5518: 5517: 5515: 5491: 5485: 5452: 5443: 5441:10.17487/RFC3168 5425: 5419: 5394: 5385: 5383:10.17487/RFC2474 5363: 5357: 5336: 5327: 5325:10.17487/RFC0791 5302: 5296: 5295: 5286: 5284:10.17487/RFC1726 5264: 5258: 5257: 5232: 5226: 5217: 5208: 5206:10.17487/RFC3701 5190: 5184: 5135: 5126: 5124:10.17487/RFC2460 5105: 5099: 5098: 5096: 5094: 5089:on 7 August 2011 5085:. Archived from 5078: 5072: 5071: 5063: 5057: 5056: 5054: 5052: 5037: 5031: 5030: 5028: 5027: 5018:. Archived from 5012: 5006: 5005: 5003: 5002: 4988: 4982: 4961: 4952: 4950:10.17487/RFC1812 4931: 4925: 4916: 4907: 4905:10.17487/RFC1716 4889: 4883: 4882: 4870: 4864: 4860: 4851: 4849:10.17487/RFC3021 4833: 4827: 4786: 4777: 4775:10.17487/RFC1122 4756: 4747: 4730: 4721: 4719:10.17487/RFC0923 4709:ASSIGNED NUMBERS 4706:(October 1984). 4696: 4690: 4681: 4672: 4670:10.17487/RFC3232 4651: 4645: 4641: 4624: 4622:10.17487/RFC6676 4602: 4596: 4579: 4562: 4560:10.17487/RFC5771 4540: 4531: 4518: 4509: 4507:10.17487/RFC2544 4491: 4485: 4476: 4467: 4465:10.17487/RFC3068 4449: 4443: 4430: 4421: 4419:10.17487/RFC7526 4395: 4389: 4380: 4363: 4361:10.17487/RFC5737 4341: 4330: 4326: 4317: 4315:10.17487/RFC3927 4299: 4293: 4284: 4267: 4265:10.17487/RFC6598 4245: 4239: 4222: 4213: 4211:10.17487/RFC1918 4195: 4182: 4181: 4179: 4172: 4164: 4158: 4157: 4155: 4154: 4140: 4134: 4133: 4131: 4130: 4113: 4107: 4082: 4065: 4063:10.17487/RFC6890 4043: 4026: 4025: 4023: 4022: 4008: 4002: 4001: 3999: 3998: 3984: 3978: 3977: 3975: 3974: 3960: 3951: 3950: 3916: 3902: 3889: 3882: 3867: 3852: 3846: 3835: 3775: 3773: 3772: 3767: 3704: 3702: 3701: 3696: 3556: 3542: 3535: 3528: 3520: 3519: 3513: 3511: 3510: 3505: 3497: 3492: 3481: 3472: 3470: 3469: 3464: 3405: 3391: 3384: 3377: 3369: 3368: 3361: 3359: 3358: 3353: 3345: 3340: 3329: 3247:IP fragmentation 3134: 3133: 2773: 2772: 2682: 2681: 2649: 2648: 2635: 2634: 2617: 2616: 2608:ones' complement 2584: 2583: 2570: 2569: 2533: 2532: 2522: 2521: 2481: 2480: 2470: 2469: 2451: 2450: 2442:dropping packets 2432: 2431: 2405: 2404: 2390: 2389: 2376: 2375: 2074: 2070: 2036:Packet structure 1963:laptop computers 1921: 1920: 1917: 1910: 1909: 1906: 1843: 1842: 1839: 1826: 1818: 1817: 1802: 1801: 1780: 1779: 1775: 1774: 1767: 1766: 1763: 1760: 1753: 1752: 1749: 1736: 1735: 1728: 1727: 1720: 1719: 1712: 1711: 1704: 1703: 1696: 1695: 1688: 1687: 1680: 1679: 1672: 1671: 1668: 1665: 1658: 1657: 1654: 1641: 1633: 1632: 1617: 1616: 1595: 1594: 1590: 1589: 1582: 1581: 1574: 1573: 1566: 1565: 1562: 1559: 1549: 1548: 1545: 1508: 1507: 1504: 1501: 1494: 1493: 1414: 1413: 1392: 1391: 1388: 1367: 1366: 1363: 1320: 1316: 1303:Private networks 1284: 1279:255.255.255.255 1265: 1264: 1261: 1240: 1217: 1216: 1213: 1192: 1173: 1165:198.51.100.0/24 1154: 1153: 1135:Private network 1132: 1131: 1108:relay (included 1098: 1079: 1056: 1037: 1036: 1033: 1004: 1003: 978: 977: 974: 947: 946: 943: 922: 921: 918: 897: 896: 893: 863: 859: 817: 816: 809:most significant 745: 744: 737: 736: 729: 728: 721: 720: 684: 683: 645:private networks 639: 638: 635: 632: 521:Internet traffic 478: 471: 464: 126: 125: 86: 84: 79: 36: 22: 18: 5843: 5842: 5838: 5837: 5836: 5834: 5833: 5832: 5783: 5782: 5759: 5754:Wayback Machine 5737: 5732: 5731: 5722: 5721: 5717: 5708: 5706: 5702: 5701: 5697: 5612: 5608: 5599: 5597: 5587: 5583: 5525: 5521: 5492: 5488: 5426: 5422: 5364: 5360: 5303: 5299: 5265: 5261: 5246: 5234: 5233: 5229: 5191: 5187: 5106: 5102: 5092: 5090: 5079: 5075: 5064: 5060: 5050: 5048: 5038: 5034: 5025: 5023: 5014: 5013: 5009: 5000: 4998: 4990: 4989: 4985: 4932: 4928: 4890: 4886: 4871: 4867: 4834: 4830: 4757: 4750: 4697: 4693: 4652: 4648: 4603: 4599: 4541: 4534: 4492: 4488: 4450: 4446: 4422:. BCP 196. 4396: 4392: 4342: 4333: 4300: 4296: 4276:. BCP 153. 4246: 4242: 4196: 4185: 4177: 4170: 4166: 4165: 4161: 4152: 4150: 4142: 4141: 4137: 4128: 4126: 4116:Davis, Lidija. 4114: 4110: 4074:. BCP 153. 4044: 4029: 4020: 4018: 4010: 4009: 4005: 3996: 3994: 3988:"IPv6 – Google" 3986: 3985: 3981: 3972: 3970: 3962: 3961: 3957: 3900: 3895: 3885: 3883: 3876: 3871: 3870: 3853: 3849: 3836: 3832: 3827: 3810: 3782: 3743: 3740: 3739: 3726:fragment offset 3711: 3660: 3657: 3656: 3557:(8-byte blocks) 3555: 3554:Fragment offset 3548: 3541: 3534: 3527: 3482: 3480: 3478: 3475: 3474: 3458: 3455: 3454: 3406:(8-byte blocks) 3404: 3403:Fragment offset 3397: 3390: 3383: 3376: 3330: 3328: 3326: 3323: 3322: 3315:header checksum 3308:fragment offset 3281: 3249: 3243: 3137:Protocol Number 3123: 2646: 2645: 2632: 2631: 2614: 2613: 2582:Header checksum 2581: 2580: 2567: 2566: 2530: 2529: 2520:Fragment offset 2519: 2518: 2478: 2477: 2467: 2466: 2448: 2447: 2429: 2428: 2411:type of service 2402: 2401: 2387: 2386: 2373: 2372: 2348:(if IHL > 5) 2301:Header checksum 2272:Fragment offset 2058: 2038: 2026:IPv6 deployment 2003: 1950: 1944: 1918: 1915: 1914: 1907: 1904: 1903: 1885: 1857: 1851: 1840: 1837: 1836: 1815: 1813: 1799: 1797: 1772: 1771: 1764: 1761: 1758: 1757: 1750: 1747: 1746: 1733: 1732: 1725: 1724: 1717: 1716: 1709: 1708: 1701: 1700: 1694:192.168.255.255 1693: 1692: 1686:192.168.255.255 1685: 1684: 1677: 1676: 1669: 1666: 1663: 1662: 1655: 1652: 1651: 1630: 1628: 1614: 1612: 1587: 1586: 1579: 1578: 1571: 1570: 1563: 1560: 1557: 1556: 1546: 1543: 1542: 1526: 1520: 1505: 1502: 1499: 1498: 1491: 1490: 1486: 1480: 1444: 1411: 1409: 1389: 1386: 1384: 1370:Single Class A 1364: 1361: 1359: 1336: 1305: 1282: 1262: 1259: 1257: 1238: 1232:233.252.0.0/24 1214: 1211: 1209: 1190: 1184:203.0.113.0/24 1171: 1151: 1149: 1129: 1127: 1121:192.168.0.0/16 1096: 1090:192.88.99.0/24 1077: 1054: 1034: 1031: 1029: 1001: 999: 993:169.254.0.0/16 975: 972: 970: 944: 941: 939: 919: 916: 914: 894: 891: 889: 841: 827:(IANA) and the 814: 813: 765:network classes 753: 742: 741: 734: 733: 726: 725: 718: 717: 681: 680: 657: 640:(2) addresses. 636: 633: 630: 628: 609: 602: 567:internetworking 563: 540: 509:packet-switched 503:methods in the 501:internetworking 482: 302:Transport layer 82: 80: 77: 56:Internetworking 39: 17: 12: 11: 5: 5841: 5831: 5830: 5825: 5820: 5815: 5810: 5805: 5800: 5795: 5781: 5780: 5775: 5757: 5744: 5736: 5735:External links 5733: 5730: 5729: 5715: 5695: 5606: 5595:ipwithease.com 5581: 5519: 5506:(4): 295–306. 5486: 5420: 5358: 5297: 5259: 5244: 5227: 5219:Informational. 5185: 5100: 5073: 5058: 5032: 5007: 4983: 4926: 4884: 4865: 4828: 4748: 4691: 4683:Informational. 4646: 4643:Informational. 4597: 4571:. BCP 51. 4532: 4520:Informational. 4486: 4478:Informational. 4444: 4390: 4382:Informational. 4331: 4294: 4240: 4183: 4159: 4135: 4108: 4027: 4003: 3992:www.google.com 3979: 3954: 3953: 3875: 3872: 3869: 3868: 3847: 3829: 3828: 3826: 3823: 3822: 3821: 3816: 3809: 3806: 3781: 3778: 3765: 3762: 3759: 3756: 3753: 3750: 3747: 3735:more fragments 3730: 3729: 3722: 3719:more fragments 3710: 3707: 3694: 3691: 3688: 3685: 3682: 3679: 3676: 3673: 3670: 3667: 3664: 3649:More Fragments 3640: 3639: 3636: 3633: 3630: 3627: 3624: 3620: 3619: 3616: 3613: 3610: 3607: 3604: 3600: 3599: 3596: 3593: 3590: 3587: 3584: 3580: 3579: 3576: 3573: 3570: 3567: 3564: 3560: 3559: 3552: 3550:More fragments 3545: 3538: 3531: 3524: 3503: 3500: 3495: 3491: 3488: 3485: 3462: 3449: 3448: 3445: 3442: 3439: 3436: 3433: 3429: 3428: 3425: 3422: 3419: 3416: 3413: 3409: 3408: 3401: 3399:More fragments 3394: 3387: 3380: 3373: 3351: 3348: 3343: 3339: 3336: 3333: 3319: 3318: 3311: 3304: 3301:more fragments 3297: 3280: 3277: 3262:Internet Layer 3245:Main article: 3242: 3239: 3236: 3235: 3232: 3227: 3223: 3222: 3219: 3214: 3210: 3209: 3206: 3201: 3197: 3196: 3193: 3188: 3184: 3183: 3180: 3175: 3171: 3170: 3167: 3162: 3158: 3157: 3154: 3149: 3145: 3144: 3141: 3138: 3122: 3119: 3118: 3117: 3114: 3113: 3110: 3107: 3103: 3102: 3099: 3096: 3092: 3091: 3088: 3085: 3081: 3080: 3077: 3074: 3070: 3069: 3066: 3063: 3059: 3058: 3055: 3052: 3048: 3047: 3044: 3041: 3037: 3036: 3033: 3030: 3026: 3025: 3022: 3019: 3015: 3014: 3011: 3008: 3004: 3003: 3000: 2997: 2993: 2992: 2989: 2986: 2982: 2981: 2978: 2975: 2971: 2970: 2967: 2964: 2960: 2959: 2956: 2953: 2949: 2948: 2945: 2942: 2938: 2937: 2934: 2931: 2927: 2926: 2923: 2920: 2916: 2915: 2912: 2909: 2905: 2904: 2901: 2898: 2894: 2893: 2890: 2887: 2883: 2882: 2879: 2876: 2872: 2871: 2868: 2865: 2861: 2860: 2857: 2854: 2850: 2849: 2846: 2843: 2839: 2838: 2835: 2832: 2828: 2827: 2824: 2821: 2817: 2816: 2813: 2810: 2806: 2805: 2802: 2799: 2795: 2794: 2791: 2788: 2784: 2783: 2780: 2777: 2769: 2768: 2760: 2759: 2756: 2755: 2752: 2749: 2745: 2744: 2741: 2738: 2734: 2733: 2730: 2727: 2723: 2722: 2711: 2708: 2704: 2703: 2700: 2697: 2693: 2692: 2689: 2686: 2678: 2677: 2674: 2662: 2650: 2643: 2636: 2629: 2618: 2615:Source address 2611: 2604: 2601: 2585: 2578: 2571: 2564: 2557: 2534: 2527: 2523: 2516: 2512: 2496: 2495: 2494: 2491: 2488: 2482: 2475: 2471: 2468:Identification 2464: 2452: 2445: 2434: 2422: 2407: 2395: 2391: 2384: 2377: 2367: 2366: 2363: 2359: 2358: 2355: 2351: 2350: 2342: 2339: 2335: 2334: 2327: 2324: 2320: 2319: 2316:Source address 2312: 2309: 2305: 2304: 2297: 2290: 2283: 2280: 2276: 2275: 2268: 2261: 2258:Identification 2254: 2251: 2247: 2246: 2239: 2232: 2225: 2218: 2211: 2208: 2204: 2203: 2200: 2197: 2194: 2191: 2188: 2185: 2182: 2179: 2176: 2173: 2170: 2167: 2164: 2161: 2158: 2155: 2152: 2149: 2146: 2143: 2140: 2137: 2134: 2131: 2128: 2125: 2122: 2119: 2116: 2113: 2110: 2107: 2102: 2098: 2097: 2094: 2091: 2088: 2085: 2080: 2057: 2054: 2037: 2034: 1998: 1997: 1987: 1981: 1946:Main article: 1943: 1940: 1889:point-to-point 1884: 1881: 1853:Main article: 1850: 1847: 1830: 1829: 1823: 1822: 1819: 1811: 1807: 1806: 1803: 1795: 1794:Network space 1791: 1790: 1787: 1784: 1645: 1644: 1638: 1637: 1636:192.168.5.255 1634: 1626: 1622: 1621: 1618: 1610: 1609:Network space 1606: 1605: 1602: 1599: 1519: 1516: 1482:Main article: 1479: 1476: 1443: 1440: 1423: 1422: 1419: 1418: 1415: 1407: 1404: 1403:192.168.0.0/16 1401: 1397: 1396: 1393: 1382: 1379: 1376: 1372: 1371: 1368: 1357: 1354: 1351: 1347: 1346: 1338: 1333: 1330: 1324: 1304: 1301: 1300: 1299: 1296: 1295: 1288: 1285: 1280: 1277: 1273: 1272: 1269: 1266: 1255: 1252: 1248: 1247: 1244: 1243:Documentation 1241: 1236: 1233: 1229: 1228: 1221: 1218: 1207: 1204: 1200: 1199: 1196: 1195:Documentation 1193: 1188: 1185: 1181: 1180: 1177: 1176:Documentation 1174: 1169: 1166: 1162: 1161: 1158: 1155: 1147: 1144: 1143:198.18.0.0/15 1140: 1139: 1136: 1133: 1125: 1122: 1118: 1117: 1112:address block 1102: 1099: 1094: 1091: 1087: 1086: 1083: 1082:Documentation 1080: 1075: 1072: 1068: 1067: 1060: 1057: 1052: 1049: 1045: 1044: 1041: 1038: 1027: 1024: 1023:172.16.0.0/12 1020: 1019: 1008: 1005: 997: 994: 990: 989: 982: 979: 968: 965: 961: 960: 951: 948: 937: 934: 933:100.64.0.0/10 930: 929: 926: 923: 912: 909: 905: 904: 901: 898: 887: 884: 880: 879: 876: 873: 870: 869:Address range 867: 866:Address block 840: 837: 752: 749: 656: 653: 601: 598: 582:connectionless 571:internet layer 562: 559: 539: 536: 484: 483: 481: 480: 473: 466: 458: 455: 454: 453: 452: 445: 440: 435: 430: 422: 421: 415: 414: 413: 412: 405: 400: 395: 390: 385: 375: 374: 373: 368: 355: 354: 352:Internet layer 348: 347: 346: 345: 338: 333: 328: 323: 318: 313: 305: 304: 298: 297: 296: 295: 288: 283: 278: 273: 268: 263: 258: 253: 248: 243: 238: 233: 228: 223: 218: 213: 208: 203: 198: 193: 188: 183: 178: 168: 163: 158: 148: 140: 139: 133: 132: 122: 121: 116: 110: 109: 104: 98: 97: 92: 88: 87: 74: 70: 69: 64: 60: 59: 53: 49: 48: 45: 41: 40: 37: 29: 28: 26:Protocol stack 15: 9: 6: 4: 3: 2: 5840: 5829: 5826: 5824: 5821: 5819: 5816: 5814: 5811: 5809: 5806: 5804: 5801: 5799: 5796: 5794: 5791: 5790: 5788: 5779: 5776: 5771: 5766: 5762: 5758: 5755: 5751: 5748: 5745: 5742: 5739: 5738: 5725: 5719: 5705: 5699: 5692: 5688: 5684: 5680: 5676: 5672: 5668: 5664: 5660: 5656: 5652: 5648: 5644: 5639: 5636: 5631: 5626: 5622: 5621: 5616: 5610: 5596: 5592: 5585: 5578: 5574: 5570: 5566: 5561: 5558: 5554: 5550: 5545: 5540: 5536: 5532: 5531: 5523: 5514: 5509: 5505: 5501: 5497: 5490: 5483: 5479: 5475: 5471: 5467: 5463: 5459: 5455: 5450: 5447: 5442: 5437: 5433: 5432: 5424: 5417: 5413: 5409: 5405: 5401: 5397: 5392: 5389: 5384: 5379: 5375: 5374: 5369: 5362: 5355: 5351: 5347: 5343: 5339: 5334: 5331: 5328:. STD 5. 5326: 5321: 5317: 5313: 5312: 5307: 5301: 5293: 5290: 5285: 5280: 5276: 5275: 5270: 5263: 5255: 5251: 5247: 5245:9781509007066 5241: 5237: 5231: 5224: 5220: 5215: 5212: 5207: 5202: 5198: 5197: 5189: 5182: 5178: 5174: 5170: 5166: 5162: 5158: 5154: 5150: 5146: 5142: 5138: 5133: 5130: 5125: 5120: 5116: 5115: 5110: 5104: 5088: 5084: 5077: 5069: 5062: 5047: 5043: 5036: 5022:on 2011-01-25 5021: 5017: 5011: 4997: 4993: 4987: 4980: 4976: 4972: 4968: 4964: 4959: 4956: 4951: 4946: 4942: 4941: 4936: 4930: 4923: 4919: 4914: 4911: 4906: 4901: 4897: 4896: 4888: 4880: 4876: 4869: 4863: 4858: 4855: 4850: 4845: 4841: 4840: 4832: 4825: 4821: 4817: 4813: 4809: 4805: 4801: 4797: 4793: 4789: 4784: 4781: 4778:. STD 3. 4776: 4771: 4767: 4766: 4761: 4755: 4753: 4746: 4741: 4737: 4733: 4728: 4725: 4720: 4715: 4711: 4710: 4705: 4701: 4695: 4688: 4684: 4679: 4676: 4671: 4666: 4662: 4661: 4656: 4650: 4644: 4639: 4636: 4632: 4628: 4623: 4618: 4614: 4610: 4609: 4601: 4594: 4590: 4586: 4582: 4577: 4574: 4570: 4566: 4561: 4556: 4552: 4548: 4547: 4539: 4537: 4529: 4526:and RFC 4525: 4521: 4516: 4513: 4508: 4503: 4499: 4498: 4490: 4483: 4479: 4474: 4471: 4466: 4461: 4457: 4456: 4448: 4441: 4437: 4433: 4428: 4425: 4420: 4415: 4411: 4407: 4406: 4401: 4394: 4387: 4383: 4378: 4375: 4371: 4367: 4362: 4357: 4353: 4349: 4348: 4340: 4338: 4336: 4329: 4324: 4321: 4316: 4311: 4307: 4306: 4298: 4291: 4287: 4282: 4279: 4275: 4271: 4266: 4261: 4257: 4253: 4252: 4244: 4237: 4233: 4229: 4225: 4220: 4217: 4214:. BCP 5. 4212: 4207: 4203: 4202: 4194: 4192: 4190: 4188: 4176: 4169: 4163: 4149: 4145: 4139: 4125: 4124: 4119: 4112: 4105: 4101: 4097: 4093: 4089: 4085: 4080: 4077: 4073: 4069: 4064: 4059: 4055: 4051: 4050: 4042: 4040: 4038: 4036: 4034: 4032: 4017: 4013: 4007: 3993: 3989: 3983: 3969: 3965: 3959: 3955: 3952: 3948: 3944: 3940: 3936: 3932: 3928: 3924: 3920: 3915: 3910: 3906: 3899: 3893: 3888: 3881: 3865: 3861: 3857: 3851: 3844: 3840: 3834: 3830: 3820: 3817: 3815: 3812: 3811: 3805: 3803: 3799: 3795: 3791: 3787: 3777: 3763: 3760: 3757: 3754: 3751: 3748: 3745: 3736: 3727: 3723: 3720: 3716: 3715: 3714: 3706: 3692: 3689: 3686: 3683: 3680: 3677: 3674: 3671: 3668: 3665: 3662: 3653: 3650: 3645: 3637: 3634: 3631: 3628: 3625: 3622: 3621: 3617: 3614: 3611: 3608: 3605: 3602: 3601: 3597: 3594: 3591: 3588: 3585: 3582: 3581: 3577: 3574: 3571: 3568: 3565: 3562: 3561: 3553: 3551: 3546: 3539: 3532: 3525: 3522: 3521: 3518: 3515: 3501: 3498: 3493: 3489: 3486: 3483: 3460: 3446: 3443: 3440: 3437: 3434: 3431: 3430: 3426: 3423: 3420: 3417: 3414: 3411: 3410: 3402: 3400: 3395: 3388: 3381: 3374: 3371: 3370: 3367: 3363: 3349: 3346: 3341: 3337: 3334: 3331: 3316: 3312: 3309: 3305: 3302: 3298: 3295: 3291: 3290: 3289: 3285: 3279:Fragmentation 3276: 3274: 3270: 3267:In contrast, 3265: 3263: 3259: 3255: 3248: 3233: 3231: 3228: 3225: 3224: 3220: 3218: 3215: 3212: 3211: 3207: 3205: 3202: 3199: 3198: 3194: 3192: 3189: 3186: 3185: 3181: 3179: 3176: 3173: 3172: 3168: 3166: 3163: 3160: 3159: 3155: 3153: 3150: 3147: 3146: 3143:Abbreviation 3142: 3140:Protocol Name 3139: 3136: 3135: 3132: 3130: 3126: 3111: 3108: 3105: 3104: 3100: 3097: 3094: 3093: 3089: 3086: 3083: 3082: 3078: 3075: 3072: 3071: 3067: 3064: 3061: 3060: 3056: 3053: 3050: 3049: 3046:Router Alert 3045: 3042: 3039: 3038: 3034: 3031: 3028: 3027: 3023: 3020: 3017: 3016: 3012: 3009: 3006: 3005: 3001: 2998: 2995: 2994: 2990: 2987: 2984: 2983: 2979: 2976: 2973: 2972: 2968: 2965: 2962: 2961: 2957: 2954: 2951: 2950: 2946: 2943: 2940: 2939: 2935: 2932: 2929: 2928: 2924: 2921: 2918: 2917: 2913: 2910: 2907: 2906: 2902: 2899: 2896: 2895: 2891: 2888: 2885: 2884: 2880: 2877: 2874: 2873: 2869: 2866: 2863: 2862: 2858: 2855: 2852: 2851: 2847: 2844: 2841: 2840: 2836: 2833: 2830: 2829: 2826:Record Route 2825: 2822: 2819: 2818: 2814: 2811: 2808: 2807: 2804:No Operation 2803: 2800: 2797: 2796: 2792: 2789: 2786: 2785: 2781: 2778: 2775: 2774: 2771: 2770: 2766: 2762: 2761: 2753: 2750: 2747: 2746: 2742: 2739: 2737:Option Length 2736: 2735: 2731: 2728: 2726:Option Number 2725: 2724: 2720: 2716: 2712: 2709: 2706: 2705: 2701: 2698: 2695: 2694: 2690: 2687: 2684: 2683: 2680: 2679: 2675: 2672: 2668: 2663: 2659: 2655: 2654:options field 2651: 2644: 2641: 2637: 2630: 2627: 2623: 2619: 2612: 2609: 2605: 2602: 2599: 2595: 2590: 2586: 2579: 2576: 2572: 2565: 2562: 2558: 2555: 2551: 2547: 2543: 2539: 2536:An eight-bit 2535: 2528: 2524: 2517: 2513: 2510: 2506: 2502: 2497: 2492: 2489: 2486: 2485: 2483: 2476: 2472: 2465: 2462: 2457: 2453: 2446: 2443: 2439: 2435: 2426: 2423: 2420: 2419:Voice over IP 2416: 2412: 2408: 2399: 2396: 2392: 2385: 2382: 2378: 2371: 2370: 2364: 2361: 2360: 2356: 2353: 2352: 2349: 2347: 2340: 2337: 2336: 2333: 2332: 2325: 2322: 2321: 2318: 2317: 2310: 2307: 2306: 2303: 2302: 2296: 2295: 2289: 2288: 2281: 2278: 2277: 2274: 2273: 2267: 2266: 2260: 2259: 2252: 2249: 2248: 2245: 2244: 2238: 2237: 2231: 2230: 2224: 2223: 2217: 2216: 2209: 2206: 2205: 2201: 2198: 2195: 2192: 2189: 2186: 2183: 2180: 2177: 2174: 2171: 2168: 2165: 2162: 2159: 2156: 2153: 2150: 2147: 2144: 2141: 2138: 2135: 2132: 2129: 2126: 2123: 2120: 2117: 2114: 2111: 2108: 2106: 2103: 2100: 2099: 2084: 2081: 2079: 2076: 2075: 2069: 2067: 2063: 2053: 2051: 2047: 2043: 2033: 2031: 2027: 2023: 2019: 2014: 2011: 2007: 2001: 1995: 1991: 1988: 1985: 1982: 1979: 1976: 1975: 1974: 1972: 1968: 1964: 1954: 1949: 1939: 1936: 1934: 1930: 1926: 1922: 1911: 1900: 1897: 1892: 1890: 1887:A unnumbered 1880: 1878: 1874: 1869: 1867: 1862: 1859:Hosts on the 1856: 1846: 1844: 1824: 1821:203.0.113.31 1820: 1812: 1809: 1808: 1805:203.0.113.16 1804: 1796: 1793: 1792: 1788: 1785: 1782: 1781: 1778: 1776: 1768: 1754: 1742: 1739: 1737: 1729: 1721: 1714:, etc. Also, 1713: 1710:192.168.2.255 1705: 1702:192.168.1.255 1697: 1689: 1681: 1673: 1659: 1639: 1635: 1627: 1624: 1623: 1619: 1611: 1608: 1607: 1603: 1600: 1597: 1596: 1593: 1591: 1588:192.168.5.255 1583: 1575: 1572:255.255.255.0 1568:(subnet mask 1567: 1552: 1550: 1539: 1535: 1531: 1525: 1515: 1513: 1509: 1495: 1485: 1475: 1473: 1469: 1465: 1461: 1457: 1452: 1450: 1439: 1436: 1432: 1428: 1416: 1405: 1402: 1399: 1398: 1394: 1380: 1378:172.16.0.0/12 1377: 1374: 1373: 1369: 1355: 1352: 1349: 1348: 1344: 1343: 1339: 1334: 1332:Address range 1331: 1328: 1325: 1322: 1321: 1315: 1314: 1313: 1311: 1293: 1289: 1286: 1278: 1275: 1274: 1270: 1267: 1253: 1250: 1249: 1245: 1242: 1234: 1231: 1230: 1226: 1222: 1219: 1205: 1202: 1201: 1197: 1194: 1186: 1183: 1182: 1178: 1175: 1167: 1164: 1163: 1159: 1156: 1145: 1142: 1141: 1137: 1134: 1123: 1120: 1119: 1115: 1111: 1107: 1103: 1100: 1092: 1089: 1088: 1084: 1081: 1073: 1071:192.0.2.0/24 1070: 1069: 1065: 1061: 1058: 1050: 1048:192.0.0.0/24 1047: 1046: 1042: 1039: 1025: 1022: 1021: 1017: 1013: 1009: 1006: 995: 992: 991: 987: 983: 980: 966: 963: 962: 959: 955: 952: 949: 935: 932: 931: 927: 924: 910: 907: 906: 902: 899: 885: 882: 881: 877: 874: 871: 868: 865: 864: 858: 857: 856: 854: 850: 846: 836: 834: 830: 826: 822: 818: 810: 806: 802: 798: 794: 790: 786: 782: 777: 775: 770: 766: 761: 759: 748: 746: 743:127.0.255.250 738: 730: 722: 714: 710: 705: 703: 699: 698:CIDR notation 695: 693: 689: 685: 676: 674: 670: 666: 662: 652: 650: 646: 641: 626: 625:address space 618: 613: 607: 597: 595: 591: 587: 583: 578: 576: 572: 568: 558: 556: 552: 548: 543: 535: 533: 528: 526: 522: 518: 514: 510: 506: 502: 498: 494: 490: 479: 474: 472: 467: 465: 460: 459: 457: 456: 451: 450: 446: 444: 441: 439: 436: 434: 431: 429: 426: 425: 424: 423: 420: 417: 416: 411: 410: 406: 404: 401: 399: 396: 394: 391: 389: 386: 383: 379: 376: 372: 369: 367: 364: 363: 362: 359: 358: 357: 356: 353: 350: 349: 344: 343: 339: 337: 334: 332: 329: 327: 324: 322: 319: 317: 314: 312: 309: 308: 307: 306: 303: 300: 299: 294: 293: 289: 287: 284: 282: 279: 277: 274: 272: 269: 267: 264: 262: 259: 257: 254: 252: 249: 247: 244: 242: 239: 237: 234: 232: 229: 227: 224: 222: 219: 217: 214: 212: 209: 207: 204: 202: 199: 197: 194: 192: 189: 187: 184: 182: 179: 176: 172: 169: 167: 164: 162: 159: 156: 152: 149: 147: 144: 143: 142: 141: 138: 135: 134: 131: 128: 127: 120: 117: 115: 111: 108: 107:Network layer 105: 103: 99: 96: 93: 89: 75: 71: 68: 65: 61: 57: 54: 50: 46: 42: 35: 30: 27: 23: 5760: 5718: 5707:. Retrieved 5698: 5642: 5619: 5609: 5598:. Retrieved 5594: 5584: 5564: 5529: 5522: 5503: 5499: 5489: 5453: 5430: 5423: 5395: 5372: 5361: 5337: 5310: 5300: 5273: 5262: 5235: 5230: 5218: 5195: 5188: 5136: 5113: 5103: 5091:. Retrieved 5087:the original 5076: 5061: 5049:. Retrieved 5035: 5024:. Retrieved 5020:the original 5010: 4999:. Retrieved 4995: 4986: 4962: 4939: 4929: 4917: 4894: 4887: 4878: 4868: 4861: 4838: 4831: 4787: 4764: 4743: 4731: 4708: 4694: 4682: 4659: 4649: 4642: 4607: 4600: 4580: 4545: 4519: 4496: 4489: 4477: 4454: 4447: 4431: 4404: 4400:B. Carpenter 4393: 4381: 4346: 4327: 4304: 4297: 4285: 4250: 4243: 4223: 4200: 4175:the original 4162: 4151:. Retrieved 4147: 4138: 4127:. Retrieved 4121: 4111: 4083: 4048: 4019:. Retrieved 4016:www.iana.org 4015: 4006: 3995:. Retrieved 3991: 3982: 3971:. 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Reynolds 4655:J. Reynolds 3968:BGP Reports 3864:MAC address 3802:reverse ARP 3533:Header size 3382:Header size 2914:Traceroute 2903:Time Stamp 2779:Option Name 2765:Option Type 2748:Option Data 2688:Size (bits) 2587:The 16-bit 1786:Binary form 1734:192.168.2.0 1726:192.168.1.0 1718:192.168.0.0 1678:192.168.0.0 1670:255.255.0.0 1664:192.168.0.0 1601:Binary form 1580:192.168.5.0 1558:192.168.5.0 1223:In use for 908:10.0.0.0/8 803:introduced 692:hexadecimal 590:upper layer 38:IPv4 packet 5787:Categories 5709:2012-05-10 5600:2022-11-21 5109:S. Deering 5051:3 February 5026:2011-01-23 5001:2021-11-25 4153:2020-08-19 4129:2024-05-10 4021:2022-01-28 3997:2022-01-28 3973:2013-01-09 3947:Q104661268 3931:9708517136 3894:) : 3874:References 3724:The field 3709:Reassembly 2980:Stream ID 2859:MTU Reply 2848:MTU Probe 2561:traceroute 2509:traceroute 2461:fragmented 2046:link layer 1877:namespaces 1522:See also: 1353:10.0.0.0/8 883:0.0.0.0/8 758:rest field 751:Allocation 606:IP address 600:Addressing 580:IPv4 is a 507:and other 419:Link layer 91:Influenced 5643:Obsolete. 5615:J. Postel 5553:2070-1721 5306:J. Postel 5254:972636788 5137:Obsolete. 4918:Obsolete. 4760:R. Braden 4745:network". 4732:Obsolete. 4704:J. 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Baker 3943:Wikidata 3860:Ethernet 3856:IEEE 802 3843:Evil bit 3808:See also 3796:(DHCP), 3258:fragment 3106:222/0xDE 3095:205/0xCD 3084:158/0x9E 3073:152/0x98 3062:151/0x97 3051:149/0x95 3040:148/0x94 3029:147/0x93 3018:145/0x91 3007:144/0x90 2996:142/0x8E 2985:137/0x89 2974:136/0x88 2963:134/0x86 2952:133/0x85 2941:131/0x83 2930:130/0x82 2751:Variable 2568:Protocol 2440:without 2357:⋮ 2354:⋮ 2294:Protocol 1929:loopback 1861:Internet 1631:11111111 1615:00000000 1512:loopback 1478:Loopback 1449:Zeroconf 1433:, which 1342:Classful 821:classful 769:classful 715:address 713:loopback 505:Internet 58:protocol 4402:(ed.). 3543:(bytes) 3536:(bytes) 3529:(bytes) 3392:(bytes) 3385:(bytes) 3378:(bytes) 2919:94/0x5E 2908:82/0x52 2897:68/0x44 2886:30/0x1E 2875:25/0x19 2870:ENCODE 2864:15/0x0F 2853:12/0x0C 2842:11/0x0B 2831:10/0x0A 2715:control 2647:Options 2515:packet. 2374:Version 2346:Options 2215:Version 1660:subnet 1287:Subnet 1064:DS-Lite 1018:server 1007:Subnet 688:decimal 673:periods 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