Networks

Ask something
Question Locked

multiple subnets through a single interface with dhcp relay

0 helpful
3 replies

by dryflies 1 view

Closed to new repliesThis discussion is closed. It stays readable, but it takes no new replies.
I have a pix in router mode and am trying to add a new /24 subnet. I added a VLAN for the new subnet and tagged it for trunking all the way to a single leaf node. unfortunately dhcp does not give it an address. the dhcp server log shows the request coming from the native interface on the pix instead of the subinterface. Do I need to put the old subnet on a subinterface with a VLAN and tag it for trunking as well? its vlan is untagged on all switches and not defined on the pix.

3 replies

by cg it

then the new subnet should work.

If your adding a new subnet to a new VLAN, yeah you have to have a trunk line and some method of routing between VLANs [eg router on a stick].

Where's the DHCP server ? is it on the old subnet?

I assume your using VTP.

by dryflies

I figured it out. I have to put the old subnet on a vlan and disable traffic through the "physical" interface requiring all traffic to go through one of the logical interfaces and onto the trunk. The hard part was finding the configuration guide for pix70. finally found where someone had posted it onto one of the cisco forums. No router on a stick, the pix is in router mode. Thanks for your response.

This discussion is closed to new replies.