DHCP / seperate VLAN

Nuddsj used Ask the Experts™

After reading some posts here what I want to do seems to be possible but if someone could confirm and if it is possibe provide some pointers that would be great.

So basically I want to create a new VLAN so that I can move IP phones off my main network to this seperate VLAN. I have x1 2008 R2 server running as DHCP, with one NIC on the main network.

I have HP layer 3 switches, so I created a new VLAN as shown below;

vlan 100
   name "VOIP_VLAN"
   ip helper-address (IP of DHCP server)
   ip address
   tagged 36

vlan 1
   name "DEFAULT_VLAN"
   untagged 1-35,37-A4
   ip address XXX.XXX.XXX.XXX
   no untagged 36
   ip igmp

I have created a new scope on the DHCP server, issuing out, however when I plug my laptop into port 36 I dont get a DHCP address

Any help would be great

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It sounds like you need to make sure you have allowed the IP of your DHCP server to be a DHCP relay in your VLAN. You will do this on the switch. Let me know if you need more info on how to do this.
Sorry, I am now seeing where you have the ip helper address listed. If you have physical connectivity to the DHCP server from vlan 100, then I would double check the scope and make sure that it is correct. Maybe try to disable it and enable it.

The only time I can remember having a problem when I set it up as you have described is when the scope was not working correctly and I fixed it from the DHCP server.
Make sure you can ping both ways; from the DHCP server to (switch)  and  from (switch) to the DHCP server.
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On the switch I can ping the DHCP server, though thew switch is also on the main VLAN so would I somehow need to ping from the new vlan on the switch

Though the DHCP server I cant ping the which I gave the VOIP_VLAN
This sounds like a similar issue. Read it, and let me know if it applies to your problem.




I guess that is the problem.

Alternative option if easier, should I just add a second NIC to the DHCP give that NIC a IP on the same subnet as the VOIP_VLAN and patch into a port of the switch that I have added to that VLAN?


I think I have just missed a step. Just re-checked the switch and under IP configuration, "IP routing is disabled"...
You need to setup routing between the subnet of your DHCP server, and the  192.168.50.x subnet. If these are indeed HP layer3 switches, you have all you need ot make this work - without adding another NIC to your DHCP server. HP layer 3 switches are not cheap, use them to your advantage. Here's some info on setting up HP swtich routing:

Can you post your full HP config file (scrub the sensitive data).

...after posting, I just saw your new comment. Yes, turn on IP routing.

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