topic Re: default gateway problem with vlan in Switches, Hubs, and Modems

default gateway problem with vlan

Russ_57 — Thu, 13 Jul 2006 08:04:53 GMT

Greetings all. Trying to setup my first vlan on 5308. Using subnetted class b. I am fortunate to have a lab to play with, so I have tried to copy my live environment. Created two vlans plus default. They route and pass dhcp ok, even attach to my test domain, but I can't get them to access the Internet. Also I can't get any vlan except the default to ping the firewall/router that is attached to the Internet. The dfgw on the default_vlan is 172.16.16.3; the address of the "firewall/router" is 172.16.16.1. I will attach my config file. Thanks in advance for any suggestions.
Russ

Re: default gateway problem with vlan

Jonathan Axford — Thu, 13 Jul 2006 09:16:07 GMT

Hi Russ,

Which port is the firewall/router attached to? Is it attached directly to that switch or does it go through another device?
I am just looking at the way you have your VLAN tagging setup.
The main difference between the VLANS i can see is that port A4 is tagged in VLANs 100 and 200 but not in VLAN 1.

Re: default gateway problem with vlan

Russ_57 — Thu, 13 Jul 2006 12:09:39 GMT

The firewall/router is attached to a port in the default_vlan. Does it need to be on a tagged port?

Re: default gateway problem with vlan

Russ_57 — Thu, 13 Jul 2006 13:43:40 GMT

OK, I have tried putting the firewall on the tagged port..after tagging it on all vlan's. When configured this way even vlan1 (default_vlan)will not ping the firewall. If the firewall is connected to an untagged port on vlan1 it responds to ping but will not allow internet access. So I have removed all tagged ports in all vlans. Still 'stumped'. :(

Re: default gateway problem with vlan

Matt Hobbs — Thu, 13 Jul 2006 18:24:11 GMT

Hi Russ,

Try adding a default route:

ip route 0.0.0.0 0.0.0.0 172.16.16.1

This should allow VLAN 1 to get out to the Internet. For your other VLANs, you will need to configure the firewall/router to point back to the 5300xl.

e.g.
on the firewall:
ip route 172.16.48.0 255.255.240.0 172.16.16.3

As usual, don't forget to assign points to any replies you receive.

Re: default gateway problem with vlan

Russ_57 — Fri, 14 Jul 2006 08:42:49 GMT

Thanks Matt. It works great. Now I can start planning the "real" thing. By the way, can you point me to some HP manuals that contain info that might help me. I didn't "see" anything about that in the 5300 manual. Thanks again.
Russ

Re: default gateway problem with vlan

Matt Hobbs — Fri, 14 Jul 2006 09:33:09 GMT

The manuals mention default routes (Advanced Traffic Management Guide), but they don't really help with questions like this. They seem to assume a lot. What you've asked is a common question and all you need is a quick example and then it makes complete sense. Everyone goes through this at one point or another.

What has helped me in the past are the free training courses available at:

http://www.hp.com/rnd/training/tech_training.htm (IP Routing Foundations in particular)

And if you can get yourself on the Adaptive Edge Fundamentals course, and the Routing Switch Essentials, it should really help your general networking skills.

Adaptive Edge is more layer 2 based, but it's still an excellent course in my opinion.

While doing these courses you end up kicking yourself a few times as you learn things and think, if I only knew that before...

Re: default gateway problem with vlan

Russ_57 — Fri, 14 Jul 2006 09:39:30 GMT

Thanks Matt, I did take the AEF course, but let it get cold before I used it. I appreciate the course link, I'll definitly use it. I have taken some of the free on-line courses that HP offers and found them to be very helpful.

Re: default gateway problem with vlan

Russ_57 — Fri, 14 Jul 2006 09:45:00 GMT

Thanks for all the help.