Problem assigning class D IPADDR because of SIOCIFADDR: Invalid argument

clu · 01-31-2004, 02:07 PM

I am trying to setup a multicast server/client pair using java. I am running slackware 8.1. In order to do this I need to assign a class D IPADDRR to my server. I have tried doing this by editing IPADDR="230.0.0.4" for eth0 in /etc/rc.d/rc.inet1. when I run the script rc.inet1 it says:
SIOCADDRT: file exists.
Configuring eth0
ifconfig eth0 230.0.0.4 broadcast 230.255.255.0 netmask 255.255.255.0
SIOCIFADDR: invalid argument
SIOCSIFBRDADDR: Cannot assign requested address.
SIOCSIFNETMASK: Cannot assign requested address.

ifconfig eth0 says that UP BROADCAST RUNNING MULTICAST.

thanks alot for any help.
-clu

Astro · 01-31-2004, 02:11 PM

try running `netconfig` and when it asks set the IP for static and put it in there where the ip field is. That should take care of it, I would think.

clu · 01-31-2004, 02:29 PM

I ran netconfig as suggested, and tried pinging 230.0.0.4 and got a network is unreachable message.
Then I ran /etc/rc.d/rc.inet1 and it returned the same error message about SIOCIFADDR: invalid argument. Thanks for your suggestion, any other ideas would still be very helpful.

djbanaan · 02-01-2004, 07:06 AM

I don't know very much about multicast, but I'd say your subnetting is wrong. If you use a 230.0.0.0/24 network (24 network bits giving it a mask of 255.255.255.0), the broadcast address is 230.0.0.255.
If you would make it a /8 network (netmask 255.0.0.0) then the broadcast address would be 230.255.255.255, but never 230.255.255.0.
The broadcast address is always the highest address in a subnet. In the subnet you're using the hightest address is 230.0.0.255.