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

Attention: The Community will be in read-only mode on 12/14/2017 from 12:00 am pacific to 11:30 am.

During this time you will only be able to see content. Other interactions such as posting, replying to questions, or marking content as helpful will be disabled for few hours.

We apologize for the inconvenience while we perform important updates to the Community.

New Member

IP Helper and Forward

I use Etrust Anti-virus and in order to centrally manage all the workstation on different subnets it discovers them by broadcast UDP packets on port 42508.

Currently my Etrust admin server can see everything on it's local subnet, but can't see anything on other subnets because the router isn't passing the broadcasts.

If I add the Admin Server as a IP Helper and also add an ip directed broadcast - the admin can see all clients on all subnets. I really don't want to have all the broadcast being directed tho - only want UDP port 42508.

I thought I could remove the ip directed broadcast and then add a global paramenter of IP Forward-Protocol UDP 42508. Should that have done it? It's not forwarding the broadcast to my etrust admin server.

Any Help much appreciated!

Thanks

3 REPLIES
VIP Purple

Re: IP Helper and Forward

Hello,

the ip helper in conjunction with the ip forward-protocol udp command should do it, you are right. Can you check if the default UDP Discovery/Broadcast port (42508) might have been changed to something else ?

Regards,

GP

New Member

Re: IP Helper and Forward

Nope its a fresh install.. default port and I can see it when I turn on debug.

When I have just the admin server as an Ip helper and the forward-protocol udp 42508 set, the debug file looks like this:

UDP: rcvd src=172.22.1.204(4569), dst=172.22.11.255(42508), length=57

1w0d: UDP: rcvd src=172.22.1.205(4570), dst=172.22.11.255(42508), length=57

1w0d: UDP: rcvd src=172.22.1.202(4571), dst=172.22.11.255(42508), length=57

1w0d: UDP: rcvd src=172.22.1.63(4572), dst=172.22.11.255(42508), length=57

It's not passing the broadcast on to the helper.... other things are getting passed on like:

1w0d: UDP: rcvd src=172.22.11.87(138), dst=172.22.11.255(138), length=209

1w0d: UDP: forwarded broadcast 138 from 172.22.11.87 to 172.22.1.66 on Vlan1

So... then If I put ip directed-broadcast in the interface it works... it passes on the broadcast to the helper.

New Member

Re: IP Helper and Forward

"So... then If I put ip directed-broadcast in the interface it works... it passes on the broadcast to the helper."

And on that note Along with all the other broadcast that I don't want to be broadcast.

Trying to do an accesslist too... didn't work. Same effect - not passing on broadcast to helper.

127
Views
0
Helpful
3
Replies
CreatePlease to create content