topic Re: Different gatways for different VLANS in Switches, Hubs, and Modems

Different gatways for different VLANS

Grant Carmichael — Wed, 12 Jul 2006 11:50:23 GMT

Now that I've got the 5308xl routing across VLANS, I'm planning to bring more VLANS onto the switch. However, I'd like the new VLANS to be routed to a different gateway than the existing VLANS. That's because we have two separate physical networks. When we move to a contiguous network, I'll have all the VLANS pointing to one gateway.

So, is it possible on a 5308 to have 2 gateways and have traffic routed based on their VLAN. If so, can you point me to any documentation? If not, I guess I could always let our sonicwall device route to different gateways based on subnets?

Thanks for your help! =)

Grant

Re: Different gatways for different VLANS

RobB_8 — Wed, 12 Jul 2006 14:20:56 GMT

yes... you can have it route based on subnet
in the menu under IP config, enable IP routing... note this will kick everyone off the network, so I would console into the swtich or make sure you are on the same subnet as the switch before doing this.
then go to the command line and go into configure terminal and add:
ip route "subnet" "mask" "gateway" ie ip route 0.0.0.0 0.0.0.0 192.168.1.254 (it is good to have a 0.0.0.0, this is a catch all for any unknown/ outbound traffic
then add a route for each subnet
ie
vlan 1 uses 172.24.192.0 ip range
ip route 172.24.192.0 255.255.255.0 172.24.192.254
vlan 2 uses 10.100.0.0 ip range
ip route 10.100.0.0 255.255.0.0 10.100.255.254
I have heard rumors that adding a lot of static routes on many of the HP switches can cause a lot of CPU load... especially with the 2600's.
Hope this helps

Re: Different gatways for different VLANS

Matt Hobbs — Wed, 12 Jul 2006 17:59:09 GMT

It also depends on if you're routing to a known destination or not.

For example, if for both of these VLANs they require internet access through different gateways, you'll need a default route 0.0.0.0 for each, this is not possible on the 5300xl.

Maybe your sonicwall can do some form of load sharing or Policy Based Routing which is what you need.

You may want to have a look through this thread:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1022139

Re: Different gatways for different VLANS

Grant Carmichael — Wed, 12 Jul 2006 19:07:38 GMT

Yep, that will be a problem then. I'll look to see if the sonicwall can do the job.

What about blocking certain vlans from other vlans, can you do that? Basically, if I have dorms on VLAN 1 and Labs on VLAN2, can I keep VLAN 1 from seeing VLAN 2 on the 5308? I'm asking before I researched it, so I apologize.

Thanks!

Grant

Re: Different gatways for different VLANS

Matt Hobbs — Wed, 12 Jul 2006 19:38:34 GMT

Yes that is possible using Access Control Lists on the 5300xl. If you can attach your running config here (remove any sensitive information like public IP address, and SNMP community names), then someone can probably make some ACL recommendations to achieve what you're after.