[c-nsp] ip helper-address, VRF, and Windows 2008 DHCP Server

[Michele Bergonzoni]

John Gill wrote:

> The DHCP DISCOVER should be a broadcast

It should be a broadcast when exiting the client, i.e. on the client's 
subnet. The DHCP relay (helper-address funcionality) transforms it in an 
unicast packet from the (primary) IP of the router's interface facing 
the client, to the DHCP server.

The server should reply to the source it sees, i.e. the IP of the router 
interface. The router should transform this into an IP broadcast to the 
MAC address of the client, or to the broadcast MAC address if the 
broadcast bit was set in the request.

> perhaps this is why your server doesn't reply to it.

There must be some other reason, which I bet is buried in the event log 
or in some other log, if the server has a correct scope. I see nothing 
obviously wrong in that request.

>> Client MAC address: Avaya_86:13:ed (b4:b0:17:86:13:ed)
 >> Option: (t=60,l=13) Vendor class identifier = "ccp.avaya.com"

Maybe it's configured to avoid answering to Avaya phones or IP phones in 
general? This is not an uncommon setup.

Bye,
			Bergonz

-- 
Ing. Michele Bergonzoni - Laboratori Guglielmo Marconi S.p.a.
Phone:+39-051-4392826 e-mail: bergonz at labs.it
alt.advanced.networks.design.configure.operate