routing problem with dhcp and localhost

drowstar · 01-03-2005, 08:23 AM

Hello everyone,
please help me set my network up correctly.

I recently changed my network setup to use dhcp (by acquiring a new router to take the place of the old hub and replacing the adsl-pppoe-setup with a dhcp-based one).

Ever since, I have had problems with slow application startup. It obviously has something to do with the new network since it coincided. I suspect there is a problem with the lookup of localhost as blocking the route to 127.0.0.1 (route add -net 127.0.0.1 netmask 255.255.255.255 reject) makes the symptoms go away. (Thanks to jdlcomputers, who gave me a hint to check my routing table). While I can at the moment work normally, I am quite certain that this is not the appropriate solution.

What could be wrong with my setup?
Would adding an appropriate loopback device to the routing table help?
Somehow I cannot associate an IP with the loopback device (I tried route add -net 127.0.0.1 netmask 255.255.255.255 dev lo, but it resulted in a SIOCADDRT: No such device).

What can I do to stop connections from trying to look up localhost? Or do it correctly?

Thanks for any suggestion,
- drowstar

A few file contents and outputs that might be interesting:
content of /etc/hosts:
127.0.0.1 localhost localhost.localdomain drow.localdomain drow
# IPV6 versions of localhost and co follow (omitted as it doesn't seem related)
content of /etc/resolv.conf:
nameserver 192.168.1.1 #the router, commented out or not doesnt make a difference
# two more nameservers supplied by my ISP
output of 'router -n':

Code:

127.0.0.1       -               255.255.255.255 !H    0      -        0 -
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0
0.0.0.0         192.168.1.1     0.0.0.0         UG    1      0        0 eth0

output of 'hostname -i':
127.0.0.1
I can ping my router and any outside internet address, but there's no way in pinging localhost: Before I blocked 127.0.0.1 it would result in 100% packet loss, now it responds with a connect: Network is unreachable (probably expected, right?).

You can see my previous posts on the same problem here:
- can't ping localhost, Internet works fine"
- using dhcpcd on gentoo slows down application startup in KDE.
Sorry for the repeated posts on this single problem. I found it appropriate to ask again since the problem is quite different from what I originally believed.

Thanks again!