[c-nsp] UDP-helper problem

[Michael Robson]

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


Thanks,

Michael
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