Insert routes into table manually with static routing

This is just an experiment i was trying to do, may be doesn't make any sense in real life networks.
Define static routes on R1- R2- R3 such end to end interfaces from R1-R2 and R2-R3 all interfaces have different subnet .

Configuring IP addresses on interfaces

For Router1
R1#conf igure terminal
R1(config)#interface Serial0/0
R1(config)# ip address
For Router2
R2#conf igure terminal
R2(config)#interface Serial0/0
R2(config)# ip address
R2(config)#interface Serial0/1
R2(config)# ip address

For Router3
R3#conf igure terminal
R3(config)#interface Serial0/0
R3(config)# ip address
Checking ip address on Router interfaces

Configuring Static routes on Router R1

1. In the first line, we are Assigning Static Route to R2 – S0/0
ip route – used for assigning static ip routing . – defines the destination network address . defines subnet mask of destination ( ) network address .
S0/0- defines the interface of router R1 from which packet should came out to reach destination.
Note: Instead of using interface of router, we can also use next hop ip address
I.e. In this, will be defined instead of s0/0.
2. Second line defines static route from R1 to R2-s0/1
3. Third one used to define static route for R3-s0/0.
In the same way, we will define static routes for R2 and R3.

For R2:

For R3:

Checking the ip routes on routers .
For R1:

For R2:

For R3:

Should it work or not …..confusion ?
Why it should not work :
Since end to end interfaces of routers having different subnet and thus to make communication between them we need to use a Router to communicate them (L3 device).
Why it should work:
As we have defined static routes, router will just check :
• In which network it has to send packet.
• From which interface it packet will should be send.

So, if we take example from router R1 to R3-s0/0

  • Router R1 will send packet from it’s S0/0 that will when reach interface of it’s end to end connected router (R2) interface s0/0.
  • Now router R2 will check in it’s routing table if it has path for

Yes, there static route exist in R2 routing table as it’s network address is

Now, On R2 we have defined path to address of thorough interface S0/0.

Thus, packet reach the destination .

Similarly, process will work for other routes from all routers.

Difference in routing table when end to end devices IP addresses are defines in same Subnet or in different Subnet

  • For end to end interfaces with different subnet

For End to end interfaces with same subnet

S – Static route
C – Connected route

Now, that’s obvious that makes conclusion :

  • if subnet will be changed on end to end interfaces and we need to define static routes to send packets to/through next hop interface and routing table add that route as Static Route. Display them as S
  • If subnet remain same on end to end interfaces, no need to define static routes for them as they are directly connected . display them as C

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