Can anyone please help me on how to configure a router with only a loopback ip address.
And without any ip address on both the lan interfaces.
I want to connect a router which has only 1 loopback ip address to my core switch 1 and core swicth 2.
Using both the LAN insterface on the router.
Thank You in advance,
A loopback IP address is just for self testing and if you are not going to configure the router interface (e.g. fa0/0/1) with an IP address then the entire communication is not possible.
A network packet need source ip and destination ip in order to reach to it's destination.
Anyone correct me if i am wrong.
for me it is not clear what you want to achieve with this config.
In my eyes you could configure the two LAN interfaces with bridging and the Layer 3 interface would then be a BVI (bridged virtual interface).
Then you have a direct Layer 2 connection between your two LAN interfaces as well as between your two core switches.
I don't think that an "ip unnumbered Lo0" on both LAN interfaces will have success because then you have the same subnet on two interfaces.
What i am trying to achieve is to create a loopback ip address on the router. And all communication to the router will be to the loopback ip address.
Loopback ip : 10.10.10.1/24
Gi 0/1 : Connected to core 1 (vlan 10 = 10.10.10.0/24)
Gi 0/2 : Connected to core 2 (vlan 10 = 10.10.10.0/24).
Basicly, it is just a physical layer redundancy.
in my eyes you can not do this with only the loopback.
You can try the following:
interface Gigabit 0/2 bridge-group 1!interface gigabit 0/1 bridge-group 1!interface BVI 1 ip address 10.10.10.1 255.255.255.0!bridge irbbridge 1 protocol ieee bridge 1 route ip
With this config the router will take part in the spanning tree.
Perhaps this helps.