VLAN issue

Unanswered Question
May 28th, 2007

Hi Experts,

I'm at the first step to learn VLANs so i have this topology:


I made VLAN2 and VLAN3 on both Switch no.1 and Switch no.2 with the following IP Address:



The two switches are Cisco 2950.

So 1)What should be the IP address,default-gateway and where to configure them for both switches to connect each other.

2)What should be the IP address of the router fe0/0.


Ibrahim ALwahidi

I have this problem too.
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Overall Rating: 4.5 (2 ratings)
bjornarsb Mon, 05/28/2007 - 09:31


I believe the implementation you are looking for is : router on a stick.

Keep in mind that vlan interface on 2950 is only for management of the switch. The switch just care for layer 2 (mac.adr)

The configuration on the router would be something like this:


int fe0/0

duplex auto

speed auto

int fe0/0.2

description *******management vlan****

ip add

encapsulation dot.q 2

int fe0/0.100

description *******users****

ip add

encapsulation dot.q 100.


if it does check the scroll box at the bottom right :)


int fe0/24

switchport mode trunk



s.arunkumar Mon, 05/28/2007 - 22:34

Give ur pc's in vlan 2 the range of ips,with default gateway

as one of the ip from this range..

and for vlan3 the range and default gateway

as one of the ip from this range..

create two sub-interface in routers interface fa0/0 and assign the address of

default gateway(configured on pc for each vlan) on each sub-interface.

do the trunk configuration properly allowing both the vlans....


arun :)

mohammedmahmoud Mon, 05/28/2007 - 23:30

Hi Ibrahim,

First of all your switches are Layer 2 switches, thus they will not be able to do Inter-VLAN routing, and thus you'll have to do the Inter-VLAN routing on the router (router-on-a stick), please see Bjornar suggestion above.

The default-gateway on the switches will be used in the case of management only (as the L2 switches are unable to do packet routing for its ports, it just do Layer 2 switching), it should be the ip address of the subinterface on the router that belongs to the management VLAN (VLAN1 by default).

The ip addresses that you should use on the router, are the default gateway for any hosts in this VLAN, in order to be able to reach hosts on the other VLANs (Inter-VLAN routing).

HTH, please do rate all helpful replies,

Mohammed Mahmoud.


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