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Hi, I've been trying to configure a firewall using ipchains on a machine running pretty much a stock installation of Potato -- I've done the apt-get upgrade but not dist-upgrade. My kernel is the default 2.2.19pre17, and given that /proc/net/ip_fwchains exists, I figure it has the appropriate support for using ipchains. My problem is this: whenever I use ipchains to try to filter by source address, i.e. with -s x.x.x.x/x as an option, something goes wrong. Details (I'll use *chain* to stand for any one of the chains): All the following ipchains commands work properly (i.e. checking with ipchains -L returns an intelligible response, and the packet filter seems to behave as it should given the ipchains commands): ipchains -F *chain* ipchains -P *chain* DENY ipchains -A input -i lo -j ACCEPt ipchains -A input -i eth0 -p tcp ! -y -j ACCEPT ipchains -A input -i eth0 -p icmp --destination-port 0 -j ACCEPT ipchains -A input -j DENY -l BUT when I try to filter by source address, e.g. ipchains -A input -i eth0 -s 192.168.0.0/16 -j DENY and check with ipchains -L to see my rule set, ipchains -L just seems to hang, and prints out just this: Chain input (policy ACCEPT): target prot opt source destination ports I have to hit ctrl-c to get the prompt back. When I look at /proc/net/ip_fwchains, it seems that rules with -s options make a change there (i.e. it looks like the rule gets registered there, when I check that file with more), but ipchains -L just hangs there. One more complication: this doesn't happen every time. Oddly, sometimes my whole firewall script runs and everything works -- I get a proper response from ipchains -L. But sometimes it doesn't. I've tried to establish a pattern, but other than noting that it seems to be using ipchains with the -s option that triggers it, I can't seem to detect anything that might indicate why it works sometimes but not others. Absolutely maddening. Any ideas? Anything I'm missing, or anywhere else I can check? Thanks, Marc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (OpenBSD) Comment: For info see http://www.gnupg.org iD8DBQE7xfUmwCp3zWOyN7gRAneuAKCggnQ7MIp4sxeEOg2AwUUjRR023wCfVBN6 kqYlSNPq9dNOkqiGLnCWDqc= =9M/Z -----END PGP SIGNATURE-----
