topic DHCP-relay problem with 2 VLANs in Switches, Hubs, and Modems

DHCP-relay problem with 2 VLANs

Zahar — Tue, 27 Apr 2010 11:55:15 GMT

Hello everyone!

The story:
We need to create two separate VLANs for Office and Service-center. We have Procurve 4204vl switch. Office-VLAN (192.168.10.0/24) contains DNS, DHCP, NAS and GW for internet access. Service-VLAN (192.168.11.0/24) will have a lot of incoming PCs. Computers from Service-VLAN must not see computers from Office-VLAN.

Primary task:
Computers from Service-VLAN should be able to receive IP configuration from DHCP (192.168.10.7) and have access to internet through GW (192.168.10.99).

Secondary task:
Computers from Service-VLAN should be able to access files on NAS (192.168.10.3).

I've created two VLANs. Configured two scopes on DHSP server (192.168.10.0/24 and 192.168.11.0/24). Enabled "ip routing" and "dhcp-relay" on switch. Added ip helper-address in Service-VLAN pointing to DHCP (192.168.10.7).

The problem - clients in Service-VLAN do not receive configuration from DHCP server.

Please see attached image and config for refence.

Please advise.

Re: DHCP-relay problem with 2 VLANs

Zahar — Tue, 27 Apr 2010 11:57:23 GMT

Here is config from switch:

hostname "YYY"
ip routing
snmp-server community "public" Unrestricted
vlan 1
name "DEFAULT_VLAN"
untagged 1-20,23-26
ip address 192.168.10.111 255.255.255.0
no untagged 21-22
exit
vlan 2
name "SERVICE_VLAN"
untagged 21-22
ip address 192.168.11.111 255.255.255.0
ip helper-address 192.168.10.7
exit

Re: DHCP-relay problem with 2 VLANs

Usaia Tawakevou — Wed, 28 Apr 2010 01:48:32 GMT

Verify that the DHCP scope is active and also the gateway address of the DHCP server is right. If it is using the GW(192.168.10.99) make sure that it knows where 192.167.11.0/24 network is

Also add a route a default route and point it to the GW

HTH

Re: DHCP-relay problem with 2 VLANs

Zahar — Wed, 28 Apr 2010 05:07:43 GMT

You was right.

I've added to switch GW address and 192.168.11.0/24 subnet to router.

Thanks!

Re: DHCP-relay problem with 2 VLANs

Zahar — Wed, 28 Apr 2010 05:08:27 GMT

Got it working =)