[c-nsp] UDP-helper problem

chris at lavin-llc.com chris at lavin-llc.com
Wed Mar 4 13:54:17 EST 2009

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
>  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?


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