Dan Martin wrote:
I have installed Fedora Core 4 on my firewall machine. My networked machines can browse the web, but I cannot access the loopback device, eg, for SWAT configuration.
ifconfig lo shows the loopback interface to be UP and RUNNING at inet addr 127.0.0.1
ping localhost results in 100% packet loss
The routing tables do not show a loopback entry, and if I try to add one I get errors.
Can anyone tell me what's going on?
Not entirely, but here's a bit of info that might help. I just did a "netstat -r" on Red Hat 9, FC1, FC3 and FC4. On RH9 & FC1, "lo" appears in the routing table output by netstat, while on FC3 & 4 it doesn't. Maybe it's a 2.6 kernel thing, but for whatever reason it seems "lo" doesn't need to be in the routing table for FC3 & 4. I tried "ping localhost" on 2 different FC4 systems, though, as well as 1 FC3 system, and all worked fine. They all have a fairly default configuration of iptables on them, as setup by system-config-securitylevel.
It might be worth a look at your own iptables configuration to see if something is amiss there, especially if you're running a non-standard (from a RH/Fedora perspective) setup.