topic Re: Where are VLANs defined? in Switches, Hubs, and Modems

Where are VLANs defined?

simon crelling — Fri, 07 Nov 2008 15:38:45 GMT

We have 2 5406zl and 6 2650 (48 port) switches in a central server room. I want to create VLANs to manage traffic (subnet) but I'm a little confused about how to go about the configuration. Do I define the VLANs on the 5406s and then make every 2650 members of each VLAN? Or do I have to create every VLAN on every switch?

Re: Where are VLANs defined?

cenk sasmaztin — Fri, 07 Nov 2008 18:01:43 GMT

hi SÄ°mon

my advice
you can create manually every switch on every vlan

but if you want
create dynamic vlan learning on 2650 switch with GVRP protocol
GVRP protocol running only vlan aware ethernet card or 802.1x configuration

please send me all switch show run commad print I make vlan config for you

Re: Where are VLANs defined?

simon crelling — Sat, 08 Nov 2008 09:26:52 GMT

Thanks for your reply,

Am I right in thinking I create each VLAN the same way on every switch, including the VLAN IP address? So:
all switches have VLAN ID 2 192.168.1.1/24 for example, with untagged ports for hosts and tagged (dynamic) uplink ports connected to the 5400s (which have IP Routing enabled)?

Thanks again,
Simon

Re: Where are VLANs defined?

Matt Hobbs — Sat, 08 Nov 2008 09:32:59 GMT

Almost right, do everything except set the same IP address on each device. Generally you'd only set an IP address for each VLAN on your 5400's (if you're running VRRP, otherwise just whichever one is doing the routing).

You definitely don't want to use the same IP address on multiple devices, duplicate IP addresses will cause you all sorts of grief.

For the 2650's, they just need one unique IP address in your management VLAN. I usually use VLAN 1 for that purpose.

Re: Where are VLANs defined?

cenk sasmaztin — Sat, 08 Nov 2008 09:48:19 GMT

yes you can create each vlan same way on every switch

vlan ip address must be serried
for example
switch 1 vlan 1 ip address 192.168.1.1/24
switch 2 vlan 1 ip address 192.168.1.2/24
switch 3 vlan 1 ip address 192.168.1.3/24

untagged port for host

tagged port for uplink port

but you can create vlan config two switch each uplink port must be
vlan 1 untag port all other vlan tag port

if you want communications between vlan
you can enable ip routing

Re: Where are VLANs defined?

simon crelling — Mon, 10 Nov 2008 13:43:27 GMT

Thanks guys, I've given out points for both answers.

Just to clarify:

As we currently don't have the VRRP license for our 5400s, we need to nominate one 5400 as the "router" and initially create the VLANs (with IP addresses assigned) there. Then create the VLANs (without any IP addr assigned) on every 2650 and then assign ports to the appropriate VLAN (untagged). The 2650's gig 49 & 50 ports will be untagged members of the default VLAN (1) and tagged in all other VLANs to enable traffic to be routed.

All switches have IP addresses in the default VLAN (this is already the case).

I'll look into getting the premium edge license as we also have 2 other comms cabs with 2 3500s and 8 2650s in each connected to the main cab by 10 gig fibre. The network was built before I joined but was left as a flat /8. STP is enabled on all switches but we have a big problem with slow down, possible due to large amounts of broadcast traffic...