Two default gateways on a ProCurve 5304xl switch

[Justin Meader]

I recently ran into a problem trying to help my school's network admins design a new layout for the middle school in my district. It seems the school right now basically consists of two seperate networks that can't communicate with each other, and they each have their own ISP. We decided a while ago to implement VLANs on the ProCurve switch we purchased to allow the two networks to communicate, but still keep network traffic flowing correctly to their seperate ISPs. The problem we've run into is that there is no way to define (as far as we can see) different default gateways for each VLAN. With only one default gateway, the switch would be sending ALL internet bound traffic to either one ISP or the other, or both - depending on how we configure the route. What we want to do is have on VLAN send all of its out of network traffic to one gateway, and have another VLAN send its traffic to another gateway. Is this possible with just one switch? Or do we need to purchase a second switch to accomplish this?

[Ron Kinner]

Far as I know the switch is too stupid to do what you want. A Cisco router could do this with policy routing but a 5304xl has only basic routing skills. However, you can do it if you remove the default route from the switch and tell the hosts to use the default route corresponding to their ISP's gateway instead of the switch's VLAN IP. You also have to add a route to the hosts that tells them the other network can be reached by using their VLAN's IP as the next hop.

On a window box you add a static route with:

route add A.B.C.0 mask 255.255.255.0 A.B.D.E -p

where A.B.C.0 is the network IP address of the other network and A.B.D.E is the IP address of the local VLAN assigned to the switch. The -p just tells it to store it in the registry so it remains after a reboot.

Ron

[Justin Meader]

http://www.hp.com/rnd/pdfs/switch_25xx_vlan_default_gateway_faq.pdf

Apparently there are other HP switches that would solve my problem if I'm reading this correctly. Too bad the 5304 isn't one of them.

[OLARU Dan]

No HP switch can do the trick for you. Just as Ron said, you need a router or routing switch that allow you to do Policy Based Routing. A Cisco 3550 48 EMI routing switch is perfect for this kind of job. Maybe HP ProCurve 9300 routing switches can do this kind of routing - but no 4000M, 25xx, 41xx or 53xx.

If you have a lot of users, then going to each user to do "route add" can be cumbersome.

[Justin Meader]

Thanks for the help, I appreciate it.