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Configuring VLANs

Ben Price
Occasional Visitor

Configuring VLANs

Good afternoon,

I have two networks running across a muliple switch network - connected by fibre. The main patch panel has a stack of three 48 port (think they are 2848). Connected by fibre are four other switches, and one more HP switch.

What I need to do is have a second VLAN transfering data between one of the switches in my stack to the other HP switch. I created a VLAN (id 2), gave the VLAN an IP address, assigned two untagged ports to it (47 and 48), and if I connected two devices in this IP range to these two port - they can communicate no problem. Problem is that when I create the same VLAN on the second switch - the devices cannot communicate. I realise that something is wrong - I am not experienced that much in VLANs but am reading up....

Point me in the right direction please.

Regards
Ben
1 REPLY
Jeff Carrell
Honored Contributor

Re: Configuring VLANs

you can only pass 1 vlan when you have switch-to-switch links when the ports are configured for 'untagged'...thats why your vlan2 is not passing between the switches, as vlan link ports are already config for untagged...

in order to pass multiple vlans between switches, you must config vlan#2 and on as 'tagged' on the u/l ports only...

so your config would look like this:

switch 1 and 2
vlan1
untag 48
vlan2
tag 48

connect port 48 between the 2 switches and now you'll have vlans 1 & 2 both passing traffic...

see the VLAN section of the manual for more info...(section 12 in my 2600/2800 manual)

general rules of thumb:
1) ports can only be untagged in no more than 1 vlan, they can be tagged in many vlans...
2) end device ports are generally untagged (phones may be an exception)...
3) switch-to-switch links are generally tagged...

hth...jeff