How configure firewall to allow me to send/receive multicast?

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1

I’m writing a multicast client/server in Java, but the firewall is blocking it (I confirmed this by stopping the firewall and suddenly the packets are received). How do I configure the firewall to allow me to send/receive multicast packets?

2

Allow packets with IP addresses in the range 224.0.0.0/4 through.

3

Thanks. :slight_smile: How do I do that? In the firewall app, I can’t seem to find a place to do that.

4

You probably have to add a rule to allow packets from 224.0.0.0/4 in. Out is generally not blocked. I don’t use SuSEFirewall2 so you’d have to investigate this yourself. (My machine is inside a perimeter firewall, and I play with networking on my LAN.)

5

The only thing that worked was under “Allowed Services” to open port 4997 (the port I’m using for the Multicasting) externally. But it didn’t give me a way to tie it to an IP address. Any idea how to do that?

I tried the following but they don’t work:


1. Adding a "Custom Rule" with source address:
   224.0.0.1   UDP
   224.0.0.1   TCP
   224.0.0.0/24   UDP
   224.0.0.0/24   TCP
   192.168.1.11   TCP   //This is the server's address
   192.168.1.11   UDP

None of them work.

2. Under Broadcast Configuration:

"Accepting the broadcast reply":

224.0.0.1    All UDP
224.0.0.1    All TCP
0/0            All UDP
0/0            All UDP
6

Perhaps you don’t really need the multicasting addresses at all. Without knowing what the software specifies, and whether its idea of multicasting is the accepted definition, it’s hard to say.