Re: Vlan extension

Lewis_Cipher · ‎01-13-2011

I have many VLANs setup on one network using a HP switch. I am trying to extend that network to a cisco switch via a fiber connection and then convert to gigabit for cisco. I Have a link light on the cisco but when I add a pc via a static address I cant ping anything. Do I need to add the cisco to the VLAN? I have limited access to the HP switch. Any help is appreciated.

Amit Singh · ‎01-13-2011

Yes. You have to add respective vlans on the Cisco switches. If you are carrying multiple vlans between HP and Cisco switch, you need to configure the ports on both sides as Trunk ports to carry all vlans. If you are just connecting the Cisco switch in a specific Vlan, you need to configure the same vlan on both the switchports i.e both at Cisco and HP side.

You need to get the info really on how many vlans you have on HP switch. How many vlans you want to extend between the Cisco and HP switch.

Cheers,

-amit singh

Lewis_Cipher · ‎01-13-2011

I only want to carry over about 5 IP addresses to another goegraphic area. So what steps do I need to take in order to get them working on the other side, or the cisco side? Would I just configure teh 5 ports on teh cisco switch for the VLAN? Thanks for any suggestion and speedy response.

Jon Marshall · ‎01-13-2011

Lewis

If you simply want to extend one vlan to the Cisco switch and assuming the connection is a L2 connection then -

sw1(config)# vlan 10

sw1(config-vlan)# name v10

sw1(config)# int gi0/1 <-- this connects to HP switch

sw1(config-if)# switchport

sw1(config-if)# switchport mode access

sw1(config-if)# switchport access vlan 10

then for each of the PC ports configure as above example for gi0/1 and add the following extra line -

sw1(config-if)# spanning-tree portfast

Just to emphasize, spanning-tree portfast should not be configured under the port that connects to the HP switch.

Jon

Lewis_Cipher · ‎02-10-2011

It looks like router RIP is enabled on the switch I am trying to extend the VLAN from. Will this matter if I am trying to extend the VLAN?

interface Vlan900
description xxx
ip address 172.x.x.x x.x.x.x
ip pim sparse-mode

router rip
network 10.0.0.0
network 100.0.0.0
network 172.xxx
network 172.xxx
network 172.xxx
network 192.xxx

kapathak · ‎02-10-2011

Hello Lewis,

First of all, can you tell us if you want to:

a) Extend same vlan subnet over an L3 link i.e. do something like this:

L3 link

Lan --------------SwitchA-------------------------SwitchB-------------------Lan

Vlan x Vlan x

where Vlan x on both the ends has the same subnet

or

b) L2 Trunk

Lan --------------SwitchA-------------------------SwitchB-------------------Lan

Vlanx Vlanx

where Vlan x on both ends has same subnet

I am asking this since you mentioned that RIP is running on the switch, and I assume that you would like to know if running RIP on both the switches and advertising Vlan x subnet to extend vlan across two disparate locations can work.

This wouldn't work because both the switches would check their respective routing tables and find that Vlan x's subnet is reachable on their directly connected interface as well as via the neighbor.

Lewis_Cipher · ‎02-11-2011

It is a layer 3 switch connecting to a layer. The layer 2 switch is the one I want to be able to connect to vlan on layer 3.

Lewis_Cipher · ‎02-15-2011

I just want to extend the one VLAN to another building. It looks like the other switch is layer3 (HP) using Router RIP. Will this still work when connecting to the cisco at the other end (Cisco 2960) with the configuration you gave me? Can I extend this VLAN?