[c-nsp] UDP-helper problem

[Michael Robson]

Yes there is a route to a.b.c.d and yes we can ping the DHCP server  
from everywhere, including the new sup.

On 4 Mar 2009, at 18:54, <chris at lavin-llc.com> wrote:

> On Wed Mar  4  8:00 , Michael Robson  sent:
>
>> I have recently moved the routing of a subnet from an old sup2/msfc2
>> 6500 (Version 12.1(26)E8, RELEASE SOFTWARE (fc1)) to a newer sup3/
>> msfc3 6500 (Version 12.2(18)SXF13, RELEASE SOFTWARE (fc1)). On the  
>> old
>> router the udp-helper command worked fine, but on the new router I  
>> can
>> see the DHCP address coming in but not the reply coming back and the
>> DHCP server isn't seeing the request arriving. Can anyone suggest why
>> this might have stopped working (it isn't an ACL or firewall issue as
>> there aren't any in the way) and I haven't turned _off_ any component
>> of udp-helper (i.e. using the ip forward-protocol command).
>>
>> interface Vlan937
>> description XXXYYYZZZ
>> ip address w.x.y.z 255.255.255.192
>> ip helper-address a.b.c.d
>>
>
> From this new sup, do you have a route to a.b.c.d? Can you ping the  
> DHCP server from this new sup?
>
>
> -chris
>


Michael
-- 

Michael Robson           | Tel: +44 (0) 161 275 6113
Senior Network Engineer  | Fax: +44 (0) 161 275 6120
Net North West           | Email: Michael.Robson at manchester.ac.uk