Routing table problems + Ping errors

ner0 · 07-07-2006, 09:21 AM

I'll admit beforehand, the problems I've encountered are mainly my fault!

The root of my problems was that I couldn't ping out to my network from my linux (slackware 10.2) box, however from any point in the network I could ping slack.

I thought this would most likely be a routing problem, so I decided to take a look, and (probably stupidly) cleared the routing table and opted to start from scratch with it.

My routing table is now (route -n):
Destination Gateway Genmask Flags Iface
127.0.0.1 0.0.0.0 255.255.255.255 UH lo
192.168.0.0 0.0.0.0 255.255.255.0 U eth0
0.0.0.0 192.168.0.1 0.0.0.0 UG eth0

Ifconfig -a now shows:
eth0 Link encap:ethernet...............
Inet addr: 192.168.0.141 BCast 192.168.0.255 Mask 255.255.255.0
Lots of packets, no errors...

lo Link encap: local loopback
Inet addr: 127.0.0.1 Mask 255.0.0.0
likewise, no errors, lots of packets.

If I try to ping any address I get the error: "connect: Invalid argument"

Any help would be extremely appreciated!

comprookie2000 · 07-08-2006, 07:45 PM

post /etc/resolv.conf
did you set your default gateway like this
route add default gw 192.168.0.1

sonajiso · 07-09-2006, 03:53 AM

The only thing I see wrong with your routing table is the "255.255.255.255" netmask for the loopback interface. This entry makes no sense and could break things. The lo subnet should be class A - netmask of "255.0.0.0".

This might not be the cause of your problems, but try changing the netmask, see if that helps.
Also, you might want to check if you have a firewall enabled. If so, you might want to check its settings.

PS: Running `route add default gw 192.168.0.1` would add the "0.0.0.0 192.168.0.1 0.0.0.0 UG eth0" entry into the routing table, so it seems the path to your default gateway is well defined.

ner0 · 07-10-2006, 07:46 AM

Thanks to both of you for your help, I was playing with route/ifconfig for a while trying to fix it with no avail.. however once I rebooted the problems were gone, didn't think that would help.

P.S. I think it was the netmask, as that was what I was trying to change, it just kept changing straight back!, reboot must have been the savior

Many Thanks