Forward udp broadcasts to subnet

[richardp]

Can you forward udp broadcasts to a subnet (rather than a host) using the ip helper-address command?

I have an application that relies on UDP broadcasts on UDP port 6614. I want these broadcasts to go to any device on a certain subnet (the subnet is actually a vpn pool on a PIX fw).

[rsissons]

Yes, you can use the subnet broadcast address as the helper address.

[thisisshanky]

For specific ports, use,

Router(config)#ip forward-protocol udp 6614

Forward the broadcast as a directed broadcast on to the subnet. Say for example if subnet is 192.168.1.0/24, then the helper-address command would look like, "ip helper-addres 192.168.1.255"

When you enable helper-address 8 default udp ports are always forwarded. You might want to disable them.

no ip forward-protocol udp bootpc

no ip forward-protocol udp tftp

no ip forward-protocol udp nameserver

no ip forward-protocol udp domain

no ip forward-protocol udp time

no ip forward-protocol udp tacacs

HTH

[richardp]

I tried using the broadcast address (172.17.255.255) as the helper address but I did not see any UDP traffic being forwarded. If I used the IP address the VPN client gets from the vpn pool (172.17.1.5), I could see lots of UDP traffic. I also tried using 172.17.1.255 as the helper address with no success.

Any ideas?