38:
240:
301:, to a destination host if the network prefixes of origination and destination hosts differ, or sent directly to a target host on the local network if they are the same. Routers constitute logical or physical borders between the subnets, and manage traffic between them. Each subnet is served by a designated default router but may consist internally of multiple physical
290:. All hosts on a subnet have the same network prefix. This prefix occupies the most-significant bits of the address. The number of bits allocated within a network to the prefix may vary between subnets, depending on the network architecture. The host identifier is a unique local identification and is either a host number on the local network or an interface identifier.
679:
Therefore, reserving the subnet values consisting of all zeros and all ones on the public
Internet was recommended, reducing the number of available subnets by two for each subnetting. This inefficiency was removed, and the practice was declared obsolete in 1995 and is only relevant when dealing with legacy equipment.
231:
network management when subnets are administratively controlled by different entities in a larger organization. Subnets may be arranged logically in a hierarchical architecture, partitioning an organization's network address space into a tree-like routing structure, or other structures, such as meshes.
1392:
A compliant IPv6 subnet always uses addresses with 64 bits in the host identifier. Given the address size of 128 bits, it therefore has a /64 routing prefix. Although it is technically possible to use smaller subnets, they are impractical for local area networks based on
Ethernet technology, because
580:
Subnetting is the process of designating some high-order bits from the host part as part of the network prefix and adjusting the subnet mask appropriately. This divides a network into smaller subnets. The following diagram modifies the above example by moving 2 bits from the host part to the network
1950:
It is the responsibility of the system administrator to ensure that the lengths of prefixes contained in Router
Advertisements are consistent with the length of interface identifiers for that link type. an implementation should not assume a particular constant. Rather, it should expect any lengths
230:
The benefits of subnetting an existing network vary with each deployment scenario. In the address allocation architecture of the
Internet using CIDR and in large organizations, efficient allocation of address space is necessary. Subnetting may also enhance routing efficiency, or have advantages in
401:
Given an IPv4 source address, its associated subnet mask, and the destination address, a router can determine whether the destination is on a locally connected network or a remote network. The subnet mask of the destination is not needed, and is generally not known to a router. For IPv6, however,
1415:
IPv6 does not implement special address formats for broadcast traffic or network numbers, and thus all addresses in a subnet are acceptable for host addressing. The all-zeroes address is reserved as the subnet-router anycast address. The subnet router anycast address is the lowest address in the
397:
in IPv4, before the introduction of CIDR, the network prefix could be directly obtained from the IP address, based on its highest-order bit sequence. This determined the class (A, B, C) of the address and therefore the subnet mask. Since the introduction of CIDR, however, the assignment of an IP
678:
The IETF originally discouraged the production use of these two subnets. When the prefix length is not available, the larger network and the first subnet have the same address, which may lead to confusion. Similar confusion is possible with the broadcast address at the end of the last subnet.
659:
IPv4 uses specially designated address formats to facilitate recognition of special address functionality. The first and the last subnets obtained by subnetting a larger network have traditionally had a special designation and, early on, special usage implications. In addition, IPv4 uses the
1381:
address space differs significantly from IPv4. The primary reason for subnetting in IPv4 is to improve efficiency in the utilization of the relatively small address space available, particularly to enterprises. No such limitations exist in IPv6, as the large address space available, even to
1416:
subnet, so it looks like the “network address”. If a router has multiple subnets on the same link, then it has multiple subnet router anycast addresses on that link. The first and last address in any network or subnet is not allowed to be assigned to any individual host.
1993:
The
Interface Identifier for an Ethernet interface is based on the EUI-64 identifier derived from the interface's built-in 48-bit IEEE 802 address. An IPv6 address prefix used for stateless autoconfiguration of an Ethernet interface must have a length of 64
851:
The remaining bits after the subnet bits are used for addressing hosts within the subnet. In the above example, the subnet mask consists of 26 bits, making it 255.255.255.192, leaving 6 bits for the host identifier. This allows for 62 host combinations (2−2).
417:
of each connected router, subnetting increases routing complexity. However, by careful design of the network, routes to collections of more distant subnets within the branches of a tree hierarchy can be aggregated into a
1672:
Traditionally, it was strongly recommended that subnet zero and the all-ones subnet not be used for addressing. Today, the use of subnet zero and the all-ones subnet is generally accepted and most vendors support their
1782:
It is useful to preserve and extend the interpretation of these special addresses in subnetted networks. This means the values of all zeros and all ones in the subnet field should not be assigned to actual (physical)
2077:
This document moves "Use of /127 Prefix Length
Between Routers Considered Harmful" (RFC 3627) to Historic status to reflect the updated guidance contained in "Using 127-Bit IPv6 Prefixes on Inter-Router Links" (RFC
1430:) prefix. However, this recommendation was revised to encourage smaller blocks, for example using 56-bit prefixes. Another common allocation size for residential customer networks has a 64-bit prefix.
327:
The modern standard form of specification of the network prefix is CIDR notation, used for both IPv4 and IPv6. It counts the number of bits in the prefix and appends that number to the address after a
243:
The concept of subnetting the IPv4 address space 200.100.10.0/24, which contains 256 addresses, into two smaller address spaces, namely 200.100.10.0/25 and 200.100.10.128/25 with 128 addresses each
2123:
There are no broadcast addresses in IPv6, their function being superseded by multicast addresses. In IPv6, all zeros and all ones are legal values for any field, unless specifically excluded.
316:, written in the same form used for IP addresses. For example, the subnet mask for a routing prefix that is composed of the most-significant 24 bits of an IPv4 address is written as
2221:
All customers get one /48 unless they can show that they need more than 65k subnets. If you have lots of consumer customers you may want to assign /56s to private residence sites.
2184:
1908:
For all unicast addresses, except those that start with the binary value 000, Interface IDs are required to be 64 bits long and to be constructed in
Modified EUI-64 format.
866:
There is an exception to this rule for 31-bit subnet masks, which means the host identifier is only one bit long for two permissible addresses. In such networks, usually
1725:
1693:
1660:
129:
network starting at the given address, having 24 bits allocated for the network prefix, and the remaining 8 bits reserved for host addressing. Addresses in the range
262:
An address fulfills the functions of identifying the host and locating it on the network in destination routing. The most common network addressing architecture is
227:
when the routing prefixes of the source address and the destination address differ. A router serves as a logical or physical boundary between the subnets.
2209:
449:). The ones indicate bits in the address used for the network prefix and the trailing block of zeros designates that part as being the host identifier.
1389:
methodology. It is used to route traffic between the global allocation spaces and within customer networks between subnets and the
Internet at large.
2168:
This anycast address is syntactically the same as a unicast address for an interface on the link with the interface identifier set to zero.
2270:
APNIC, ARIN, and RIPE have revised the end site assignment policy to encourage the assignment of smaller (i.e., /56) blocks to end sites.
406:(NDP). IPv6 address assignment to an interface carries no requirement of a matching on-link prefix and vice versa, with the exception of
671:. The last subnet obtained from subnetting a larger network has all bits in the subnet bit group set to one. It is therefore called the
667:
The first subnet obtained from subnetting a larger network has all bits in the subnet bit group set to zero. It is therefore called
1394:
2180:
1717:
1685:
1652:
870:, only two hosts (the endpoints) may be connected and a specification of network and broadcast addresses is not necessary.
740:
The number of subnets available and the number of possible hosts in a network may be readily calculated. For instance, the
251:. Usually, this address is unique to each device and can either be configured automatically by a network service with the
867:
256:
252:
2376:
2036:
On inter-router point-to-point links, it is useful, for security and other reasons, to use 127-bit IPv6 prefixes.
1398:
2423:
2205:
1386:
682:
Although the all-zeros and the all-ones host values are reserved for the network address of the subnet and its
332:
104:
859:
is the number of bits used for the host portion of the address. The number of available subnets is 2, where
1439:
664:
host address, i.e. the last address within a network, for broadcast transmission to all hosts on the link.
452:
The following example shows the separation of the network prefix and the host identifier from an address (
194:
operation to any IP address in the network, yields the routing prefix. Subnet masks are also expressed in
1385:
As in IPv4, subnetting in IPv6 is based on the concepts of variable-length subnet masking (VLSM) and the
403:
263:
126:
686:, respectively, in systems using CIDR all subnets are available in a subdivided network. For example, a
17:
1419:
In the past, the recommended allocation for an IPv6 customer site was an address space with a 48-bit (
1372:
431:
282:
consists of 128 bits. In both architectures, an IP address is divided into two logical parts, the
2140:
1922:
1880:
1542:
2418:
765:
subnets. The highlighted two address bits become part of the network number in this process.
335:(CIDR). In IPv6 this is the only standards-based form to denote network or routing prefixes.
1924:
IPv6 Stateless
Address Autoconfiguration - section 5.5.3.(d) Router Advertisement Processing
2356:
2329:
2302:
2262:
2160:
2115:
2069:
2028:
1985:
1967:
Transmission of IPv6 Packets over
Ethernet Networks - section 4 Stateless Autoconfiguration
1942:
1900:
1858:
1816:
1774:
1635:
1597:
1562:
1524:
1510:
Classless Inter-domain Routing (CIDR): The Internet Address Assignment and Aggregation Plan
1489:
1444:
195:
65:
31:
2095:
1965:
1824:
This practice is obsolete! Modern software will be able to utilize all definable networks.
1570:
Updated by RFC 1349, RFC 4379, RFC 5884, RFC 6093, RFC 6298, RFC 6633, RFC 6864, RFC 8029.
8:
569:
407:
398:
address to a network interface requires two parameters, the address and a subnet mask.
298:
224:
1754:
64:
Computers that belong to the same subnet are addressed with an identical group of its
2372:
2254:
683:
154:
255:(DHCP), manually by an administrator, or automatically by the operating system with
2413:
2346:
2319:
2292:
2244:
2150:
2105:
2059:
2018:
1975:
1932:
1890:
1848:
1806:
1764:
1625:
1587:
1552:
1514:
1479:
413:
Since each locally connected subnet must be represented by a separate entry in the
394:
271:
248:
2359:
2340:
2305:
2286:
2265:
2234:
2163:
2118:
2072:
2049:
2031:
2008:
2007:
M. Kohno; B. Nitzan; R. Bush; Y. Matsuzaki; L. Colitti; T. Narten (April 2011).
1988:
1945:
1903:
1861:
1842:
1819:
1796:
1638:
1615:
1600:
1581:
1565:
1527:
1508:
2332:
2313:
1777:
1492:
1469:
306:
93:
2407:
2258:
2142:
IP Version 6 Addressing Architecture - section 2.6.1 Required Anycast Address
2136:
2091:
1876:
1721:
1689:
1656:
414:
297:
of IP packets across multiple networks via special gateway computers, called
72:. This results in the logical division of an IP address into two fields: the
2181:"Subnet Router Anycast Addresses – what are they, how do they work? – Into6"
1882:
IP Version 6 Addressing Architecture - section 2.5.1. Interface Identifiers
581:
prefix to form four smaller subnets each one quarter of the previous size.
419:
279:
275:
175:
is a large address block with 2 addresses, having a 32-bit routing prefix.
549:
191:
57:. The practice of dividing a network into two or more networks is called
1911:(Updated by RFC 5952, RFC 6052, RFC 7136, RFC 7346, RFC 7371, RFC 8064.)
1579:
479:). The operation is visualized in a table using binary address formats.
37:
1750:
1465:
69:
54:
1840:
2351:
2324:
2297:
2249:
2155:
2110:
2064:
2023:
1980:
1937:
1895:
1853:
1811:
1769:
1630:
1617:
IPv6 Subnet Model: The Relationship between Links and Subnet Prefixes
1592:
1557:
1519:
1484:
239:
2006:
855:
In general, the number of available hosts on a subnet is 2−2, where
863:
is the number of bits used for the network portion of the address.
441:
An IPv4 subnet mask consists of 32 bits; it is a sequence of ones (
390:
and its network prefix consisting of the most significant 32 bits.
302:
552:
operation of IP address and the subnet mask is the network prefix
1580:
T. Narten; E. Nordmark; W. Simpson; H. Soliman (September 2007).
568:, is derived by the bitwise AND operation of the address and the
294:
187:
2097:
IP Version 6 Addressing Architecture - section 2 IPv6 Addressing
103:
may be expressed as the first address of a network, written in
2388:
CCNA Cisco Certified Network Associate Study Guide 5th Edition
1841:
A. Retana; R. White; V. Fuller; D. McPherson (December 2000).
402:
on-link determination is different in detail and requires the
111:), and ending with the bit-length of the prefix. For example,
1412:
subnets for point-to-point links, which have only two hosts.
2232:
1920:
1613:
2240:
2146:
2101:
2055:
2014:
1971:
1928:
1886:
1802:
1760:
1621:
1548:
1475:
1378:
331:(/) character separator. This notation was introduced with
267:
247:
Computers participating in an IP network have at least one
158:
1718:"Document ID 13711 - Subnet Zero and the All-Ones Subnet"
1686:"Document ID 13711 - Subnet Zero and the All-Ones Subnet"
1653:"Document ID 13711 - Subnet Zero and the All-Ones Subnet"
1794:
1748:
1544:
Requirements for Internet Hosts -- Communication Layers
1463:
312:
The routing prefix of an address is identified by the
178:
For IPv4, a network may also be characterized by its
2134:
2089:
1921:S. Thomson; T. Narten; T. Jinmei (September 2007).
1874:
1844:Using 31-Bit Prefixes on IPv4 Point-to-Point Links
754:network may be subdivided into the following four
2010:Using 127-Bit IPv6 Prefixes on Inter-Router Links
436:
234:
41:Creating a subnet by dividing the host identifier
2405:
654:
293:This addressing structure permits the selective
107:(CIDR) notation, followed by a slash character (
30:For subnets in the mathematics of topology, see
2233:T. Narten; G. Huston; L. Roberts (March 2011).
732:, reduces only the host count in each subnets.
1737:the last subnet, known as the all-ones subnet
1614:H. Singh; W. Beebee; E. Nordmark (July 2010).
1506:
1366:
425:
2399:(4th ed.). San Francisco, London: Wiley.
2394:
2342:DNS Encodings of Network Names and Other Type
2128:
1868:
223:Traffic is exchanged between subnets through
2226:
1795:Troy Pummill; Bill Manning (December 1995).
198:like an IP address. For example, the prefix
1963:
697:network can be divided into sixteen usable
1583:Neighbor Discovery for IP version 6 (IPv6)
2350:
2323:
2296:
2248:
2154:
2109:
2083:
2063:
2047:
2022:
1979:
1936:
1894:
1852:
1810:
1768:
1629:
1591:
1556:
1540:
1518:
1483:
1827:(Informational RFC, demoted to category
238:
36:
2315:Utility of subnets of Internet networks
2041:
2000:
1957:
1914:
1834:
1788:
1742:
1705:the first subnet, known as subnet zero
708:networks. Each broadcast address, i.e.
14:
2406:
2385:
1756:Internet Standard Subnetting Procedure
1607:
1573:
1534:
1500:
1471:Internet Standard Subnetting Procedure
2395:Groth, David; Skandier, Toby (2005).
2366:
1798:Variable Length Subnet Table For IPv4
1457:
1382:end-users, is not a limiting factor.
2236:IPv6 Address Assignment to End Sites
2198:
735:
27:Logical subdivision of an IP network
1395:stateless address autoconfiguration
644:00000000.00000000.00000000.00000010
631:11000000.00000000.00000010.10000000
601:11000000.00000000.00000010.10000010
538:00000000.00000000.00000000.10000010
525:11000000.00000000.00000010.00000000
512:11111111.11111111.11111111.00000000
499:11000000.00000000.00000010.10000010
257:stateless address autoconfiguration
253:Dynamic Host Configuration Protocol
24:
2279:
422:and represented by single routes.
25:
2435:
53:, is a logical subdivision of an
1997:(Updated by RFC 6085, RFC 8064.)
1507:V. Fuller; T. Li (August 2006).
445:) followed by a block of zeros (
92:is an identifier for a specific
2390:. San Francisco, London: Sybex.
2212:from the original on 2010-04-26
2187:from the original on 2022-07-02
2173:
1728:from the original on 2014-02-09
1696:from the original on 2014-02-09
1663:from the original on 2014-02-09
1541:R. Braden, ed. (October 1989).
1399:Internet Engineering Task Force
1710:
1678:
1645:
1387:Classless Inter-Domain Routing
874:Subnet masks and IP Addresses
437:Determining the network prefix
338:For example, the IPv4 network
333:Classless Inter-Domain Routing
235:Network addressing and routing
105:Classless Inter-Domain Routing
13:
1:
2288:Requirements for IPv4 Routers
1964:M. Crawford (December 1998).
1450:
655:Special addresses and subnets
575:
274:since approximately 2006. An
145:belong to this network, with
1440:Autonomous system (Internet)
7:
2051:RFC 3627 to Historic Status
2048:W. George (February 2012).
1433:
1367:Internet Protocol version 6
837:11000000.10101000.00000101.
820:11000000.10101000.00000101.
803:11000000.10101000.00000101.
786:11000000.10101000.00000101.
614:11111111.11111111.11111111.
426:Internet Protocol version 4
404:Neighbor Discovery Protocol
305:segments interconnected by
266:(IPv4), but its successor,
264:Internet Protocol version 4
212:would have the subnet mask
127:Internet Protocol version 4
10:
2440:
1370:
560:. The host part, which is
429:
29:
2367:Blank, Andrew G. (2006).
1951:of interface identifiers.
1586:. Network Working Group.
1513:. Network Working Group.
1393:64 bits are required for
1373:IPv6 subnetting reference
432:IPv4 subnetting reference
1547:. Network Working Group
368:, and the IPv6 notation
278:consists of 32 bits. An
270:, has been increasingly
190:that, when applied by a
2206:"IPv6 Addressing Plans"
382:designates the address
1954:(Updated by RFC 7527.)
1401:recommends the use of
244:
161:address specification
96:or network interface.
42:
2424:Internet architecture
2397:Network + Study Guide
2386:Lammle, Todd (2005).
592:Dot-decimal notation
490:Dot-decimal notation
460:) and its associated
346:with the subnet mask
242:
125:is the prefix of the
66:most-significant bits
40:
1497:Updated by RFC 6918.
1445:Network segmentation
868:point-to-point links
572:of the subnet mask.
408:link-local addresses
196:dot-decimal notation
32:Subnet (mathematics)
2149:. sec. 2.6.1.
1931:. sec. 5.5.3.
1889:. sec. 2.5.1.
1551:. sec. 3.3.1.
875:
395:classful networking
2369:TCP/IP Foundations
2208:. ARIN IPv6 Wiki.
1377:The design of the
873:
777:Broadcast address
548:The result of the
245:
43:
2183:. 30 March 2014.
2139:(February 2006).
2094:(February 2006).
1879:(February 2006).
1364:
1363:
849:
848:
833:192.168.5.192/26
816:192.168.5.128/26
774:Network (binary)
736:Subnet host count
684:broadcast address
652:
651:
546:
545:
155:broadcast address
16:(Redirected from
2431:
2400:
2391:
2382:
2363:
2354:
2352:10.17487/RFC1101
2336:
2327:
2325:10.17487/RFC0917
2309:
2300:
2298:10.17487/RFC1812
2273:
2272:
2252:
2250:10.17487/RFC6177
2230:
2224:
2223:
2218:
2217:
2202:
2196:
2195:
2193:
2192:
2177:
2171:
2170:
2158:
2156:10.17487/RFC4291
2132:
2126:
2125:
2113:
2111:10.17487/RFC4291
2087:
2081:
2080:
2067:
2065:10.17487/RFC6547
2045:
2039:
2038:
2026:
2024:10.17487/RFC6164
2004:
1998:
1996:
1983:
1981:10.17487/RFC2464
1961:
1955:
1953:
1940:
1938:10.17487/RFC4862
1918:
1912:
1910:
1898:
1896:10.17487/RFC4291
1872:
1866:
1865:
1856:
1854:10.17487/RFC3021
1838:
1832:
1826:
1814:
1812:10.17487/RFC1878
1792:
1786:
1785:
1772:
1770:10.17487/RFC0950
1746:
1740:
1739:
1734:
1733:
1714:
1708:
1707:
1702:
1701:
1682:
1676:
1675:
1669:
1668:
1649:
1643:
1642:
1633:
1631:10.17487/RFC5942
1611:
1605:
1604:
1595:
1593:10.17487/RFC4861
1577:
1571:
1569:
1560:
1558:10.17487/RFC1122
1538:
1532:
1531:
1522:
1520:10.17487/RFC4632
1504:
1498:
1496:
1487:
1485:10.17487/RFC0950
1461:
1428:
1427:
1424:
1410:
1409:
1406:
1359:
1358:
1344:
1343:
1340:
1330:
1329:
1315:
1314:
1311:
1301:
1300:
1286:
1285:
1282:
1272:
1271:
1257:
1256:
1253:
1243:
1242:
1228:
1227:
1224:
1214:
1213:
1199:
1198:
1195:
1185:
1184:
1170:
1169:
1166:
1156:
1155:
1141:
1140:
1137:
1127:
1126:
1112:
1111:
1108:
1098:
1097:
1083:
1082:
1079:
1069:
1068:
1054:
1053:
1050:
1040:
1039:
1025:
1024:
1021:
1011:
1010:
996:
995:
992:
982:
981:
967:
966:
963:
953:
952:
938:
937:
934:
924:
923:
909:
908:
905:
876:
872:
842:
825:
808:
799:192.168.5.64/26
791:
768:
767:
763:
762:
759:
752:
751:
748:
745:
730:
729:
722:
721:
714:
713:
706:
705:
702:
695:
694:
691:
645:
632:
622:255.255.255.192
619:
602:
584:
583:
570:ones' complement
566:
565:
558:
557:
539:
534:Host identifier
526:
513:
500:
482:
481:
477:
476:
469:
468:
465:
458:
457:
388:
387:
380:
379:
376:
373:
366:
365:
362:
359:
352:
351:
344:
343:
322:
321:
307:network switches
218:
217:
210:
209:
206:
203:
173:
172:
169:
166:
151:
150:
143:
142:
135:
134:
123:
122:
119:
116:
21:
2439:
2438:
2434:
2433:
2432:
2430:
2429:
2428:
2404:
2403:
2379:
2339:
2312:
2285:
2282:
2280:Further reading
2277:
2276:
2261:. BCP 157.
2231:
2227:
2215:
2213:
2204:
2203:
2199:
2190:
2188:
2179:
2178:
2174:
2133:
2129:
2104:. sec. 2.
2088:
2084:
2046:
2042:
2005:
2001:
1974:. sec. 4.
1962:
1958:
1919:
1915:
1873:
1869:
1839:
1835:
1793:
1789:
1753:(August 1985).
1749:Jeffrey Mogul;
1747:
1743:
1731:
1729:
1716:
1715:
1711:
1699:
1697:
1684:
1683:
1679:
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1651:
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1646:
1612:
1608:
1578:
1574:
1539:
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1505:
1501:
1468:(August 1985).
1464:Jeffrey Mogul;
1462:
1458:
1453:
1436:
1425:
1422:
1421:
1407:
1404:
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1375:
1369:
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1124:
1123:
1109:
1106:
1105:
1096:255.255.255.128
1095:
1094:
1080:
1077:
1076:
1067:255.255.255.192
1066:
1065:
1051:
1048:
1047:
1038:255.255.255.224
1037:
1036:
1022:
1019:
1018:
1009:255.255.255.240
1008:
1007:
993:
990:
989:
980:255.255.255.248
979:
978:
964:
961:
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951:255.255.255.252
950:
949:
935:
932:
931:
922:255.255.255.254
921:
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906:
903:
902:
836:
819:
802:
785:
782:192.168.5.0/26
760:
757:
756:
749:
746:
743:
742:
738:
727:
726:
719:
718:
711:
710:
703:
700:
699:
692:
689:
688:
673:all-ones subnet
657:
643:
630:
627:Network prefix
613:
600:
578:
563:
562:
555:
554:
537:
524:
521:Network prefix
511:
498:
474:
473:
466:
463:
462:
455:
454:
439:
434:
428:
385:
384:
377:
374:
371:
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363:
360:
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356:
349:
348:
341:
340:
319:
318:
288:host identifier
249:network address
237:
215:
214:
207:
204:
201:
200:
186:, which is the
170:
167:
164:
163:
148:
147:
140:
139:
132:
131:
120:
117:
114:
113:
86:host identifier
35:
28:
23:
22:
15:
12:
11:
5:
2437:
2427:
2426:
2421:
2416:
2402:
2401:
2392:
2383:
2377:
2364:
2337:
2310:
2281:
2278:
2275:
2274:
2225:
2197:
2172:
2127:
2082:
2040:
1999:
1956:
1913:
1867:
1833:
1787:
1741:
1724:. 2005-08-10.
1709:
1692:. 2005-08-10.
1677:
1659:. 2005-08-10.
1644:
1606:
1572:
1533:
1499:
1455:
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1188:
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1149:
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1130:
1129:
1120:
1117:
1114:
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1100:
1091:
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1072:
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1059:
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1014:
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1001:
998:
985:
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975:
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956:
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946:
943:
940:
927:
926:
917:
914:
911:
898:
897:
892:
887:
882:
847:
846:
845:192.168.5.255
843:
834:
830:
829:
828:192.168.5.191
826:
817:
813:
812:
811:192.168.5.127
809:
800:
796:
795:
792:
783:
779:
778:
775:
772:
737:
734:
656:
653:
650:
649:
646:
641:
637:
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628:
624:
623:
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531:
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518:
517:
516:255.255.255.0
514:
509:
505:
504:
501:
496:
492:
491:
488:
485:
438:
435:
427:
424:
415:routing tables
354:is written as
284:network prefix
236:
233:
153:as the subnet
149:198.51.100.255
141:198.51.100.255
101:routing prefix
78:routing prefix
74:network number
26:
9:
6:
4:
3:
2:
2436:
2425:
2422:
2420:
2417:
2415:
2412:
2411:
2409:
2398:
2393:
2389:
2384:
2380:
2378:9780782151138
2374:
2370:
2365:
2361:
2358:
2353:
2348:
2344:
2343:
2338:
2334:
2331:
2326:
2321:
2317:
2316:
2311:
2307:
2304:
2299:
2294:
2290:
2289:
2284:
2283:
2271:
2267:
2264:
2260:
2256:
2251:
2246:
2242:
2238:
2237:
2229:
2222:
2211:
2207:
2201:
2186:
2182:
2176:
2169:
2165:
2162:
2157:
2152:
2148:
2144:
2143:
2138:
2131:
2124:
2120:
2117:
2112:
2107:
2103:
2099:
2098:
2093:
2086:
2079:
2074:
2071:
2066:
2061:
2057:
2053:
2052:
2044:
2037:
2033:
2030:
2025:
2020:
2016:
2012:
2011:
2003:
1995:
1990:
1987:
1982:
1977:
1973:
1969:
1968:
1960:
1952:
1947:
1944:
1939:
1934:
1930:
1926:
1925:
1917:
1909:
1905:
1902:
1897:
1892:
1888:
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1883:
1878:
1871:
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1860:
1855:
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1813:
1808:
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1784:
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1776:
1771:
1766:
1763:. p. 6.
1762:
1758:
1757:
1752:
1745:
1738:
1727:
1723:
1722:Cisco Systems
1719:
1713:
1706:
1695:
1691:
1690:Cisco Systems
1687:
1681:
1674:
1662:
1658:
1657:Cisco Systems
1654:
1648:
1640:
1637:
1632:
1627:
1623:
1619:
1618:
1610:
1602:
1599:
1594:
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1467:
1460:
1456:
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1437:
1431:
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1417:
1413:
1411:
1400:
1396:
1390:
1388:
1383:
1380:
1374:
1360:
1353:
1350:
1347:
1345:
1335:
1334:
1331:
1328:255.255.128.0
1324:
1321:
1318:
1316:
1306:
1305:
1302:
1299:255.255.192.0
1295:
1292:
1289:
1287:
1277:
1276:
1273:
1270:255.255.224.0
1266:
1263:
1260:
1258:
1248:
1247:
1244:
1241:255.255.240.0
1237:
1234:
1231:
1229:
1219:
1218:
1215:
1212:255.255.248.0
1208:
1205:
1202:
1200:
1190:
1189:
1186:
1183:255.255.252.0
1179:
1176:
1173:
1171:
1161:
1160:
1157:
1154:255.255.254.0
1150:
1147:
1144:
1142:
1132:
1131:
1128:
1125:255.255.255.0
1121:
1118:
1115:
1113:
1103:
1102:
1099:
1092:
1089:
1086:
1084:
1074:
1073:
1070:
1063:
1060:
1057:
1055:
1045:
1044:
1041:
1034:
1031:
1028:
1026:
1016:
1015:
1012:
1005:
1002:
999:
997:
987:
986:
983:
976:
973:
970:
968:
958:
957:
954:
947:
944:
941:
939:
929:
928:
925:
918:
915:
912:
910:
900:
899:
896:
893:
891:
888:
886:
883:
881:
878:
877:
871:
869:
864:
862:
858:
853:
844:
840:
835:
832:
831:
827:
823:
818:
815:
814:
810:
806:
801:
798:
797:
794:192.168.5.63
793:
789:
784:
781:
780:
776:
773:
770:
769:
766:
764:
753:
733:
731:
723:
715:
707:
696:
685:
680:
676:
674:
670:
665:
663:
647:
642:
639:
638:
634:
629:
626:
625:
621:
617:
612:
609:
608:
604:
599:
596:
595:
591:
588:
586:
585:
582:
573:
571:
567:
559:
551:
541:
536:
533:
532:
528:
523:
520:
519:
515:
510:
507:
506:
502:
497:
494:
493:
489:
486:
484:
483:
480:
478:
475:255.255.255.0
471:subnet mask (
470:
459:
450:
448:
444:
433:
423:
421:
416:
411:
409:
405:
399:
396:
391:
389:
381:
367:
353:
350:255.255.255.0
345:
336:
334:
330:
325:
323:
320:255.255.255.0
315:
310:
308:
304:
300:
296:
291:
289:
285:
281:
277:
273:
269:
265:
260:
258:
254:
250:
241:
232:
228:
226:
221:
219:
216:255.255.255.0
211:
197:
193:
189:
185:
181:
176:
174:
160:
156:
152:
144:
136:
128:
124:
110:
106:
102:
97:
95:
91:
87:
83:
79:
75:
71:
67:
62:
60:
56:
52:
48:
39:
33:
19:
2419:IP addresses
2396:
2387:
2368:
2341:
2314:
2287:
2269:
2235:
2228:
2220:
2214:. Retrieved
2200:
2189:. Retrieved
2175:
2167:
2141:
2130:
2122:
2096:
2085:
2076:
2050:
2043:
2035:
2009:
2002:
1992:
1966:
1959:
1949:
1923:
1916:
1907:
1881:
1870:
1843:
1836:
1828:
1823:
1797:
1790:
1781:
1755:
1744:
1736:
1730:. Retrieved
1712:
1704:
1698:. Retrieved
1680:
1671:
1665:. Retrieved
1647:
1616:
1609:
1582:
1575:
1543:
1536:
1509:
1502:
1470:
1459:
1420:
1418:
1414:
1402:
1391:
1384:
1376:
1354:
1336:
1325:
1307:
1296:
1278:
1267:
1249:
1238:
1220:
1209:
1191:
1180:
1162:
1151:
1133:
1122:
1104:
1093:
1075:
1064:
1046:
1035:
1017:
1006:
988:
977:
959:
948:
930:
919:
901:
894:
889:
885:IP Addresses
884:
879:
865:
860:
856:
854:
850:
838:
821:
804:
787:
755:
741:
739:
725:
717:
709:
698:
687:
681:
677:
672:
668:
666:
661:
658:
635:192.0.2.128
615:
610:Subnet mask
605:192.0.2.130
589:Binary form
579:
561:
553:
547:
508:Subnet mask
503:192.0.2.130
487:Binary form
472:
461:
453:
451:
446:
442:
440:
420:supernetwork
412:
400:
392:
383:
369:
355:
347:
339:
337:
328:
326:
317:
313:
311:
292:
287:
283:
280:IPv6 address
276:IPv4 address
261:
246:
229:
222:
213:
202:198.51.100.0
199:
183:
179:
177:
162:
146:
138:
133:198.51.100.0
130:
115:198.51.100.0
112:
108:
100:
98:
89:
85:
81:
77:
73:
70:IP addresses
63:
58:
50:
46:
44:
2135:R. Hinden;
2090:R. Hinden;
1875:R. Hinden;
1357:255.255.0.0
744:192.168.5.0
669:subnet zero
597:IP address
550:bitwise AND
495:IP address
456:192.0.2.130
314:subnet mask
192:bitwise AND
180:subnet mask
2408:Categories
2216:2010-04-25
2191:2022-06-09
2137:S. Deering
2092:S. Deering
1877:S. Deering
1751:Jon Postel
1732:2010-04-23
1700:2010-04-23
1667:2010-04-25
1466:Jon Postel
1451:References
1371:See also:
640:Host part
576:Subnetting
542:0.0.0.130
529:192.0.2.0
430:See also:
386:2001:db8::
372:2001:db8::
165:2001:db8::
90:rest field
82:rest field
80:, and the
59:subnetting
55:IP network
47:subnetwork
18:Subnetwork
2371:. Wiley.
2259:2070-1721
556:192.0.2.0
358:192.0.2.0
342:192.0.2.0
68:of their
2210:Archived
2185:Archived
1829:Historic
1783:subnets.
1726:Archived
1694:Archived
1661:Archived
1434:See also
771:Network
662:all ones
648:0.0.0.2
303:Ethernet
286:and the
272:deployed
2414:Routing
895:Netmask
299:routers
295:routing
225:routers
188:bitmask
184:netmask
2375:
2257:
2078:6164).
1397:. The
1351:65534
1348:65536
1322:32766
1319:32768
1293:16382
1290:16384
841:000000
824:000000
807:000000
790:000000
618:000000
157:. The
88:. The
51:subnet
1994:bits.
1264:8190
1261:8192
1235:4094
1232:4096
1206:2046
1203:2048
1177:1022
1174:1024
890:Hosts
728:*.255
724:, …,
329:slash
49:, or
2373:ISBN
2360:1101
2306:1812
2266:6177
2255:ISSN
2241:IETF
2164:4291
2147:IETF
2119:4291
2102:IETF
2073:6547
2056:IETF
2032:6164
2015:IETF
1989:2464
1972:IETF
1946:4862
1929:IETF
1904:4291
1887:IETF
1862:3021
1820:1878
1803:IETF
1761:IETF
1673:use.
1639:5942
1622:IETF
1601:4861
1566:1122
1549:IETF
1528:4632
1476:IETF
1379:IPv6
1148:510
1145:512
1119:254
1116:256
1090:126
1087:128
880:Mask
720:*.31
712:*.15
268:IPv6
159:IPv6
99:The
94:host
2357:RFC
2347:doi
2333:917
2330:RFC
2320:doi
2303:RFC
2293:doi
2263:RFC
2245:doi
2161:RFC
2151:doi
2116:RFC
2106:doi
2070:RFC
2060:doi
2029:RFC
2019:doi
1986:RFC
1976:doi
1943:RFC
1933:doi
1901:RFC
1891:doi
1859:RFC
1849:doi
1817:RFC
1807:doi
1778:950
1775:RFC
1765:doi
1636:RFC
1626:doi
1598:RFC
1588:doi
1563:RFC
1553:doi
1525:RFC
1515:doi
1493:950
1490:RFC
1480:doi
1408:127
1061:62
1058:64
1032:30
1029:32
1003:14
1000:16
564:130
393:In
182:or
137:to
84:or
76:or
2410::
2355:.
2345:.
2328:.
2318:.
2301:.
2291:.
2268:.
2253:.
2243:.
2239:.
2219:.
2166:.
2159:.
2145:.
2121:.
2114:.
2100:.
2075:.
2068:.
2058:.
2054:.
2034:.
2027:.
2017:.
2013:.
1991:.
1984:.
1970:.
1948:.
1941:.
1927:.
1906:.
1899:.
1885:.
1857:.
1847:.
1822:.
1815:.
1805:.
1801:.
1780:.
1773:.
1759:.
1735:.
1720:.
1703:.
1688:.
1670:.
1655:.
1634:.
1624:.
1620:.
1596:.
1561:.
1523:.
1488:.
1478:.
1474:.
1426:48
1342:16
1313:17
1284:18
1255:19
1226:20
1197:21
1168:22
1139:23
1110:24
1081:25
1052:26
1023:27
994:28
974:6
971:8
965:29
936:30
907:31
839:11
822:10
805:01
788:00
761:26
750:24
716:,
704:28
693:24
675:.
616:11
467:24
410:.
378:32
364:24
324:.
309:.
259:.
220:.
208:24
171:32
121:24
61:.
45:A
2381:.
2362:.
2349::
2335:.
2322::
2308:.
2295::
2247::
2194:.
2153::
2108::
2062::
2021::
1978::
1935::
1893::
1864:.
1851::
1831:)
1809::
1767::
1641:.
1628::
1603:.
1590::
1568:.
1555::
1530:.
1517::
1495:.
1482::
1423:/
1405:/
1339:/
1310:/
1281:/
1252:/
1223:/
1194:/
1165:/
1136:/
1107:/
1078:/
1049:/
1020:/
991:/
962:/
945:2
942:4
933:/
916:2
913:2
904:/
861:n
857:h
758:/
747:/
701:/
690:/
464:/
447:0
443:1
375:/
361:/
205:/
168:/
118:/
109:/
34:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
