NETMASK AND SUBNET MASK TABLE

Netmask and Subnet Mask Table

UPDATED: August 25, 1999

For All Lucent Remote Access Products

Summary

Below is a table specifying the various netmasks that can be used. It provides the following information:

Subnet mask represented in dotted decimal and in hex

The number of bits in the network and host portions

The number of subnets and the number of hosts per subnet

Each network/subnet created by the subnet mask and its network address, range of available IP address, and the broadcast address.

Command Summary

add netmask [network] [netmask] # adds a netmask to the Lucent box del netmask [network] # removes a netmask from the Lucent box show table netmask # shows a list of all netmasks add route [destination] [gateway] [metric] # adds a route to routing table del route [destination] # removes a route from the routing table show route # displays the routing table set gateway [primary ip gateway] # sets the default route set [port/interface]routing on | broadcast | listen # configures RIP on a port/interface set default on | broadcast | listen # configures RIP as it applies to the default route.

NOTE:

Lucent Remote Access products can route the first and last subnet.

RIP v1 (which is used by Lucent) does not send netmasks with RIP broadcasts.

RIP v1 does not support variable length subnet masks (VLSM). This means you can't subnet a subnet of a subnet. It also implies that only one netmask can be applied to one network. Thus you cannot have the first half of a class C with 255.255.255.128 and then subnet the 2nd half with 255.255.255.192.

VLSM is supported on ComOS versions 3.5 and greater. VLSM is only for use with OSPF routing.

Subnet Mask Table

---------------------------------------------------------- Subnet Mask: 255.255.255.0 Hex Mask: 0xffffff00 Subnet Bits: 24 Host Bits: 8 Number of Subnets: 1 Hosts per Subnet: 254 Network Address IP Range Broadcast Address .0 .1-.254 .255 ---------------------------------------------------------- Subnet Mask: 255.255.255.128 Hex Mask: 0xffffff80 Subnet Bits: 25 Host Bits: 7 Number of Subnets: 2 Hosts per Subnet: 126 Network Address IP Range Broadcast Address .0 .1-.126 .127 .128 .129-.254 .255 ---------------------------------------------------------- Subnet Mask: 255.255.255.192 Hex Mask: 0xffffffc0 Subnet Bits: 26 Host Bits: 6 Number of Subnets: 4 Hosts per Subnet: 62 Network Address IP Range Broadcast Address .0 .1-.62 .63 .64 .65-.126 .127 .128 .129-.190 .191 .192 .193-.254 .255 ---------------------------------------------------------- Subnet Mask: 255.255.255.224 Hex Mask: 0xffffffe0 Subnet Bits: 27 Host Bits: 5 Number of Subnets: 8 Hosts per Subnet: 30 Network Address IP Range Broadcast Address .0 .1-.30 .31 .32 .33-.62 .63 .64 .65-.94 .95 .96 .97-.126 .127 .128 .129-.158 .159 .160 .161-.190 .191 .192 .193-.222 .223 .224 .225-.254 .255 ---------------------------------------------------------- Subnet Mask: 255.255.255.240 Hex Mask: 0xfffffff0 Subnet Bits: 28 Host Bits: 4 Number of Subnets: 16 Hosts per Subnet: 14 Network Address IP Range Broadcast Address .0 .1-.14 .15 .16 .17-.30 .31 .32 .33-.46 .47 .48 .49-.62 .63 .64 .65-.78 .79 .80 .81-.94 .95 .96 .97-.110 .111 .112 .113-.126 .127 .128 .129-.142 .143 .144 .145-.158 .159 .160 .161-.174 .175 .176 .177-.190 .191 .192 .193-.206 .207 .208 .209-.222 .223 .224 .225-.238 .239 .240 .241-.254 .255 --------------------------------------------------------- Subnet Mask: 255.255.255.248 Hex Mask: 0xfffffff8 Subnet Bits: 29 Host Bits: 3 Number of Subnets: 32 Hosts per Subnet: 6 Network Address IP Range Broadcast Address .0 .1-.6 .7 .8 .9-.14 .15 .16 .17-.22 .23 .24 .25-.30 .31 .32 .33-.38 .39 .40 .41-.46 .47 .48 .49-.54 .55 .56 .57-.62 .63 .64 .65-.70 .71 .72 .73-.78 .79 .80 .81-.86 .87 .88 .89-.94 .95 .96 .97-.102 .103 .104 .105-.110 .111 .112 .113-.118 .119 .120 .121-.126 .127 .128 .129-.134 .135 .136 .137-.142 .143 .144 .145-.150 .151 .152 .153-.158 .159 .160 .161-.166 .167 .168 .169-.174 .175 .176 .177-.182 .183 .184 .185-.190 .191 .192 .193-.198 .199 .200 .201-.206 .207 .208 .209-.214 .215 .216 .217-.222 .223 .224 .225-.230 .231 .232 .233-.238 .239 .240 .241-.246 .247 .248 .249-.254 .255 --------------------------------------------------------- Subnet Mask: 255.255.255.252 Hex Mask: 0xfffffffc Subnet Bits: 30 Host Bits: 2 Number of Subnets: 64 Hosts per Subnet: 2 Network Address IP Range Broadcast Address .0 .1-.2 .3 .4 .5-.6 .7 .8 .9-.10 .11 .12 .13-.14 .15 .16 .17-.18 .19 .20 .21-.22 .23 .24 .25-.26 .27 .28 .29-.30 .31 .32 .33-.34 .35 .36 .37-.38 .39 .40 .41-.42 .43 .44 .45-.46 .47 .48 .49-.50 .51 .52 .53-.54 .55 .56 .57-.58 .59 .60 .61-.62 .63 .64 .65-.66 .67 .68 .69-.70 .71 .72 .73-.74 .75 .76 .77-.78 .79 .80 .81-.82 .83 .84 .85-.86 .87 .88 .89-.90 .91 .92 .93-.94 .95 .96 .97-.98 .99 .100 .101-.102 .103 .104 .105-.106 .107 .108 .109-.110 .111 .112 .113-.114 .115 .116 .117-.118 .119 .120 .121-.122 .123 .124 .125-.126 .127 .128 .129-.130 .131 .132 .133-.134 .135 .136 .137-.138 .139 .140 .141-.142 .143 .144 .145-.146 .147 .148 .149-.150 .151 .152 .153-.154 .155 .156 .157-.158 .159 .160 .161-.162 .163 .164 .165-.166 .167 .168 .169-.170 .171 .172 .173-.174 .175 .176 .177-.178 .179 .180 .181-.182 .183 .184 .185-.186 .187 .188 .189-.190 .191 .192 .193-.194 .195 .196 .197-.198 .199 .200 .201-.202 .203 .204 .205-.206 .207 .208 .209-.210 .211 .212 .213-.214 .215 .216 .217-.218 .219 .220 .221-.222 .223 .224 .225-.226 .227 .228 .229-.230 .231 .232 .233-.234 .235 .236 .237-.238 .239 .240 .241-.242 .243 .244 .245-.246 .247 .248 .249-.250 .251 .252 .253-.254 .255 ---------------------------------------------------------- Subnet Mask: 255.255.255.255 Hex Mask: 0xffffffff Subnet Bits: 32 Host Bits: 0 Number of Subnets: 255 Hosts per Subnet: 1