5520 DHCP with VLANs

[disturbedone]

Hi, newbie on Nortel switches here....

I've come into an environment which has lots of 5520s and 2x 8010 cores. Approx 10 VLANs for various things, clients get DHCP. Also running VMware ESXi for all servers including W2K3 DHCP. Existing, old & poorly deployed, WiFi system has 2x SSIDs which are on separate VLANs and clients get DHCP. WiFi getting replaced, trialling new one in small area but clients don't get DHCP. That was the trigger but upon looking further I have trouble getting DHCP - set up new access port on VLAN40 but cannot get DHCP (wired), another wired desktop has access port on VLAN100 and gets DHCP in 10.100.x.x but switch port has default VLAN20 and is not a member of VLAN100 but somehow gets 10.100.x.x address!

To me it looks like there are more issues but the trialling of the new WiFi has just shown them up.

In Enterprise Switch Manager in 'IP Routing/DHCP' there is nothing set. Nor is that set on the 8010 router. So I can't workout how DHCP forwarding is even enabled.

Thoughts?

 

[andy88]

Try enabling dhcp relay on all vlans on the 8600's

Add the following command for each vlan;

ip dhcp-relay create-fwd-path agent <vlan ip interface> server <DHCP server> mode dhcp state enable

 

[disturbedone]

Long story but I got to the bottom of it.

One of the 8010 routers had IP Routing/DHCP info for the subnets but not the VLANs in question hence why I wasn't getting DHCP. I couldn't make an entry, it gave me an error. Looking further found a static route for the subnets of these VLANs with next hop as being the existing WiFi controller. I can only assume it says "are you one of my APs, if so I'll get DHCP for you, if you're anything else pi$$ off". So that explained why nothing other than the existing WiFi does or would ever work on that VLAN. Because we're only trialling the new WiFi I put it on other VLANs temporarily and it's fine.