Table of Contents
Default Route VLSM
Given Network: 195.100.0.0
Required hosts on Router 1: 26
Required hosts on Router 2: 14
R1<= 26 hosts
26<= 2n – 2
26<= 25 – 2
26<= 32 – 2
26<= 30
Total number of network bits= 32
32 – n = 32 – 5 = 27 (CIDR value of Router 1 i.e. Given network)
i.e. 195.100.0.0/27
N.S.M = 11111111. 11111111. 11111111.11100000
= 255.255.255.224
Block Size = 256 – N.S.M
= 256 – 224 = 32
Note: Add this block size in given network so that we can get our new network for Router 2.
so the new network is 192.100.0.32/?
Now find FVH, LVH and Broadcast address
Given Network | 195 | 100 | 0 | 0 |
First Valid Host-FVH | 195 | 100 | 0 | 1 |
Last Valid Host-LVH | 195 | 100 | 0 | 30 |
Broadcast | 195 | 100 | 0 | 31 |
New Network | 195 | 100 | 0 | 32 |
R2<= 14 hosts
14<= 2n – 2
14<= 24 – 2
14<= 16 – 2
14<= 14
Total number of network bits = 32
32 – n = 32 -4 = 28 (CIDR value of new network i.e. Router 2)
i.e. 195.100.0.32/28
N.S.M = 11111111. 11111111. 11111111.11110000
= 255.255.255.240
Block Size = 256 – N.S.M
= 256 – 240 = 16
Note: Add this block size in given network so that we can get our new network for Router 1 and 2 (Virtual Network).
so the new network is 192.100.0.48/?
Now find FVH, LVH and Broadcast address
Given Network | 195 | 100 | 0 | 32 |
First Valid Host-FVH | 195 | 100 | 0 | 1 |
Last Valid Host-LVH | 195 | 100 | 0 | 46 |
Broadcast | 195 | 100 | 0 | 47 |
New Network | 195 | 100 | 0 | 48 |
Router 1 & 2 <= 2 hosts (we required only two IP to connect 2 routers)
2 <= 2n – 2
2 <= 22 – 2
2 <= 4 – 2
2 <= 2
Total number of network bits = 32
32 – n = 32 – 2 = 30 (CIDR of Virtual network (R1&R2)
i.e. 195.100.0.48/30
N.S.M = 11111111.11111111.11111111.11111100
= 255.255.255.252
Block Size = 256 – N.S.M
= 256 – 252 = 4
Note: Add this block size in given network so that we can get our new network for Router 3. This network can be used in future.
so the new network is 192.100.0.52 /?
Now find FVH, LVH and Broadcast address
Given Network | 195 | 100 | 0 | 48 |
First Valid Host-FVH | 195 | 100 | 0 | 49 |
Last Valid Host-LVH | 195 | 100 | 0 | 50 |
Broadcast | 195 | 100 | 0 | 51 |
New Network | 195 | 100 | 0 | 52 |
Basic Configuration on Router 1
Router>enable Router#configure terminal Router(config)#hostname R1 R1(config)#interface fastEthernet 0/0 R1(config-if)#ip address 195.100.0.1 255.255.255.224 R1(config-if)#no shutdown R1(config-if)#exit R1(config)#interface serial 0/0/0 R1(config-if)#ip address 195.100.0.49 255.255.255.252 R1(config-if)#clock rate 64000 R1(config-if)#no shutdown R1(config-if)#exit R1(config)#exit R1#write |
Basic Configuration on Router 2
Router>enable Router#configure terminal Router(config)#hostname R2 R2(config)#interface fastEthernet 0/0 R2(config-if)#ip address 195.100.0.33 255.255.255.240 R2(config-if)#no shutdown R2(config-if)#exit R2(config)#interface serial 0/1/0 R2(config-if)#ip address 195.100.0.50 255.255.255.252 R2(config-if)#no shutdown R2(config-if)#exit R2(config)#exit R2#write |
Default Route Configuration on Router 1
R1>enable R1#configure terminal R1(config)#ip route 0.0.0.0 0.0.0.0 195.100.0.50 R1(config)#exit R1#write |
Default Route Configuration on Router 2
R2>enable R2#configure terminal R2(config)#ip route 0.0.0.0 0.0.0.0 195.100.0.49 R2(config)#exit R2#write |
Verification on Router 1
R1#show ip route 195.100.0.0/24 is variably subnetted, 2 subnets, 2 masks C 195.100.0.0/27 is directly connected, FastEthernet0/0 C 195.100.0.48/30 is directly connected, Serial0/0/0 S* 0.0.0.0/0 [1/0] via 195.100.0.50 |
Verification on Router 2
R2#show ip route 195.100.0.0/24 is variably subnetted, 2 subnets, 2 masks C 195.100.0.32/28 is directly connected, FastEthernet0/0 C 195.100.0.48/30 is directly connected, Serial0/1/0 S* 0.0.0.0/0 [1/0] via 195.100.0.49 |