Inter-VLAN routing question

agustinchernitsky

Hello Amigos,

Quick question: when configuring Inter-VLAN routing on a 2600 router, do we have to issue a no ip address for the interface receiving the ISL / dot1q trunk? Example from book:

#int f0/0
#no ip address
# no shutdown
# int f0/0.1
# encapsulation dot1q 1
# ip address 172.16.10.1 255.255.255.128

Or this will be fine too?:

# int f0/0.1
# encapsulation dot1q 1
# ip address 172.16.10.1 255.255.255.128

Thanks!

steve-o87

agustinchernitsky wrote:

Or this will be fine too?:

# int f0/0.1
# encapsulation dot1q 1
# ip address 172.16.10.1 255.255.255.128

Thanks!

I would go with this answer - you would set up the trunk using sub-interfaces and put them on different subnets

david_r

They are both fine and correct.

The book example makes sure that there isn't an ip address on the physical interface and to enable the interface that is disabled by default. I would hazard a guess that the author always throws in "no ip address" when moving to a logical interface.

However, if you are comfortable showing the configuration and removing what needs to be removed and enabling what needs to be enabled, there is nothing wrong with the second way. That's how I usually do it.

hectorjhrdz

only avoid to set any ip adress at the interface, if is used trunking.
otherwise you will have problems with the trunk.

whatever, if you don´t set any addres in the interface when you perform sh run command , you'll see the line "no ip address".

agustinchernitsky

Thanks amigos!

macwhizard

when configuring Inter-VLAN routing on a 2600 router....

: : : :

I have a 2600, running IOS 12.2, there isn't any encapsulation command, so can't create a trunk port . Cybex CCNA ver5 book mentions inorder to create a trunk port, the router must have atleast a Fast Ethernet port. I was wondering how you guys managed to get it.

agustinchernitsky

Your 2600 doesn't have a fa interface?

pr3d4t0r

agustinchernitsky wrote:

Your 2600 doesn't have a fa interface?

Is this possible ?

agustinchernitsky

I thought they came with a fixed fast ethernet interface... or at least a module that has one

macwhizard

agustinchernitsky wrote:

I thought they came with a fixed fast ethernet interface... or at least a module that has one

Seems, it doesn't have one.... or is it the IOS ?.