Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

vlan interfaces on routers

Hi all, if I have 4 fast ethernet interfaces on my router, and also a vlan interface, can you have an ip address on each fastethernet interface ? and can you have multiple vlans on the router ?

7 REPLIES

Re: vlan interfaces on routers

Hi Carl

If you are going to connect the trunk port of your switch to the routers ethernet then you need to create subinterfaces with respective vlan id being used as identification on the subinterfaces.

If you are going to connect simple switch ports then you can configure ip address on the ethernet port.

I dont think you can create vlans as you do in normal L2 or L3 switch instead you can create subinterfaces with respective vlan ids for the identification purpose..

regds

New Member

Re: vlan interfaces on routers

This is the config I have seen

interface FastEthernet0

!

interface FastEthernet1

!

interface FastEthernet2

!

interface FastEthernet3

!

interface Vlan1

description local-LAN

ip address x.x.x.x 255.255.255.0

ip accounting output-packets

ip route-cache flow

ip tcp adjust-mss 1452

how does this work, i guess so you can use any 4 ethernet ports, Would you have to put your switch as a trunk port so it does intervlan routing ?

Re: vlan interfaces on routers

Hi Carl

I feel you have a ESW module installed in your router which actually works as a Logical Switch installed in your router..

All the fastethernet interfaces will be part of the vlan 1 which is again being assigned with an ip address..

regds

New Member

Re: vlan interfaces on routers

Is it possible to have more vlans on here ? or just 1

Re: vlan interfaces on routers

Hi Carl

You can have more than 1 Vlan provided your IOS Code supports it..

regds

New Member

Re: vlan interfaces on routers

Hi Carl

Depends on your router model, recently I was working with a 870 Series, this models are limited to 4 Vlans, plus one routeable WAN Port which can be DSL or Ethernet. The 4 Fastethernet Ports are just Switchports, the routing has to be done on the VLAN Interfaces. On bigger plattforms this should not be a problem.

Simon

New Member

Re: vlan interfaces on routers

2950 will hold only 1 vlan interface(layer3), in my experience

3550 and above will hold multiple , but depending on OS

131
Views
0
Helpful
7
Replies