how to get a line protocol up...

[1100466]

hi everybody, i've got question:

I've got three Cisco 1605R Routers. Router_1 is connected to Router_2 (ethernet0 to ethernet0) and Router_2 is connected to Router_3 (ethernet1 to ethernet1).

By problem is that when i logged in to Router_3 and ask: "#show ip interface", i see that ethernet0 of Router_3 is up, but that the line protocol is down. How do i get the line protocol up???


i hope that you understand my question.......

 

[omartin]

What is Ethernet0 of router 3 plugged to ? If unplugged, it's the way it should be (down). But I guess it's not...

Olivier Martin
--------------
Read that somewhere and I think its cool :
If you want to accelerate a Windoze Box, there is an easy way to have it accelerate at -9.8 m/s^2

 

[1100466]

it's unplugged.

the problem is that when i'm logged in router_1, i have to ping to Ethernet0 of router_3, but since the line protocol is down, it doesn't work.

 

[omartin]

If it's unplugged, it will *never* answer to a ping as well as it will never appear up because it is not up. Create a loopback IP address on router3 if you want an answer to the ping and advertise this IP address through the routing domain (RIP ? EIGRP ?) and this will work.

Good luck !

Olivier Martin
--------------
Read that somewhere and I think its cool :
If you want to accelerate a Windoze Box, there is an easy way to have it accelerate at -9.8 m/s^2

 

[1100466]

and how do you begin what that????

 

[omartin]

There is a minimal amount of knowledge about routing you need to know before you can go further.. But basically, I'll presume you heard about RIP. If not, well do a search on it on google, i'm (and RIPv2) sure you will find tons of info on this protocol.

Creating a loopback interface is pretty easy :

interface loopback0
ip address 10.10.10.1 255.255.255.0

router rip
network 10.0.0.0

Provided that your ethernet interface is in the same classfull network (class A in this case), using the same subnet (/24) as the loopback0 interface, RIP advertisements will be sent for 10.10.10.0/24 through Ethernet1. So other routers (R2) will know that they can reach 10.10.10.0/24 network using their interfaces (R2 eth0 for instance). For this to work, you need of course that R2 also has a network using the same subnet mask as the loopback address of R3. If it's not the case, advertisements will be sent not for 10.10.10.0/24 but for 10.0.0.0/8. Depending on your network, this might not be what you want.
Olivier Martin
--------------
Read that somewhere and I think its cool :
If you want to accelerate a Windoze Box, there is an easy way to have it accelerate at -9.8 m/s^2