BCM450 DHCP

[mothandras]

For some strange reason the LAN2 which we just use for OAM just randomly decided on its own to start passing out a single IP address via DHCP.

We have setup and use LAN1 for VLAN Voice and its setup for DHCP, but LAN2 has never been setup for DHCP.

What would cause this?

 

[snowman50]

The bcm450 has a Dedicated OAM port on the left side of the Lan Ports which gives out 1 ip address
The customer Lan Ports are the next 2 which are the same ports linked to each other.
These are the ones you use for the customer Lan set up.

 

[mothandras]

I understand that, but why is it assigning a DHCP to a client on our LAN?

We already have our Windows server for DHCP.

 

[ucxguy]

You are not supposed to connect the OA&M port to your LAN. That port is intended for management only. You should connect your PC/laptop directly to this port. There is a DHCP server running on the BCM's OA&M subnet - it's purpose is to provide a single IP address to your PC/laptop.

When you connect the OA&M port to your LAN, you get two DHCP servers on the LAN (one of the Windows server and another on the BCM). When a client requests an IP address via DHCP, both servers will reply and the first response will be used by the client.

The simple solution is - never connect the OA&M port to your LAN.

 

[mothandras]

OK I can unplug it but its how we have been administrating the phone system for years without this issue.

How do I access the phone system from a workstation without the OAM being plugged in?

 

[Splic3d]

point EM to the other LAN port IP address. It does more than just the voice/ip vlan. The dhcp setup in the BCM should be set to sets only, as that will only allow nortel/avaya devices to pull an address from the BCM.

http://www.i3techgroup.com

Avaya/Nortel/NEC/Asterisk/Access Control/CCTV/DSX/Acti/UCx

 

[ucxguy]

Just enter the LAN1 IP address of the BCM system in EM. When you have the BCM connected to your LAN, there is no reason to use the OA&M port.

 

[mothandras]

We had previously been using the OAM port for Reporting/Administration, and using LAN1 for our Voice VLAN for VOIP.

When I unplugged the cable previously in the OAM port and plugged it into the LAN2 port it completely crashed our entire network.

After digging over the last few hours it appears the Spanning Tree on our Nortel Switch stack went ape-shit when this happened.

I had to manually remove/resetup the Spanning Tree on the VLAN.

Now after fixing all this, I plugged a laptop directly into the OAM port to configure the LAN2 port but it isnt showing up in the EM.

What is the LAN2 port used for? Can I enable it for use for Reporting/Administration?

 

[mothandras]

Ok, after re-reading the first response, LAN1 and LAN2 are the same port.

So if we are using LAN1 for VLAN/VOIP with a different subnet address from our Corporate LAN, how to a setup EM to manage it?

 

[mothandras]

Apparently the only way is to create a special routing statement in our ASA and create a separate VLAN for the traffic.

Going to test this after 5pm EST tonight.