Two routers connected to a switch= same IP host address?

[azizusman868]

I have two routers, name router0 and router1, that are connected to a switch on ports FA01/1 and FA0/2 respectively. Now lets say this network has and address of 201.201.201.0/24. DJMOLDING

Would the IP host address of both router interfaces that connect to this switch be the same, e.g. .1 for Router0 FA0/0, and .1 for Router1 FA0/0, or would the Router1 interface be .2?

I know in the real world, if you're connecting countries, you would not use this setup as its not ideal.

[Flavio Miranda]

Hello

 It must be ..1 and .2. Keep in mind that devices can not have the same IP address. In the scenario you describde, although we have a switch in between, both router are locally direct connected and they must be on the same network but with different IP

[Kasun Bandara]

@azizusman868 hi, you cannot have same IP for 2 different ports/hosts in same network segment. so router 0 needs to be .1 and router 1 needs to be .2. 

[MHM Cisco World]

friend you are learning, 
if you config both router with same IP then both router will show duplicated IP 
so you need to config each router with diff IP BUT in same subnet  (since both connect to SW port that assign to same VLAN ID)

[M02@rt37]

Hello @azizusman868,

Each interface of a router should have a unique IP address. Therefore, if both Router0 and Router1 are connected to the same switch, their interfaces connecting to the switch should have different IP addresses within the same network.

So, one possible configuration could be assigning the IP address 201.201.201.1 to Router0's interface (e.g., FA0/0) connected to the switch, and assigning the IP address 201.201.201.2 to Router1's interface (e.g., FA0/0) connected to the switch. This way, each router interface has a unique IP address within the same network.

[balaji.bandi]

what is the use case why you looking to have both to be .1 IP address ? because of failure scenario ?

you can use HSRP with virtual IP ? (is this workable for you ?)

[Yinan Wang]

In the most case, each device has its own ip address. The ip address can be given by static ip or dynamic ip from dhcp pool. There are different cases, the router can be given different ip addresses for the routing purpose. The static ip address for this router is the loopback0 ip address. 

[Nabari94]

Hello Aziz,
There are few situations (like multicast) where you would want to configure a same IPv4/v6 address on 2 different devices. Your scenario does not seem to be one.