Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

IP helper question

I am trying to setup ip helper for an older application. Examination of the broadcast packet shows that the ttl is set to 1.

Is there a way to change the ttl by matching the packet and having the router increase the ttl to the needed diameter?

1 REPLY
Green

Re: IP helper question

NO. And you shouldn't.

Broadcasts are meant to be kept within a broadcast domain (layer 2).

IPHELPER will convert those broadcasts into unicasts and aim them to the specified resource.

IPHELPER goes on teh broadcast side of the router, it only needs to be on the interface closest to the broadcast source, because after that, it's a unicast and will traverse the remaining network between the source and the target.

Routers should not (except with extremely rare occasions)propagate broadcasts.

If IPHELPER is not forwarding the broadcast you want it to, there are some configuration parameters you can use to add / drop services that IP HELPER will forward.

Good Luck

Scott

96
Views
0
Helpful
1
Replies