I have a server running Centos4. I found I was seeing some network problems so I tried "route" and found there was no routing. I thought reboot would solve it but it didn't. I had to manually enter a route to the default gateway, there is still no route to the loopback interface. How is this possible? I thought there was default routes built into the kernel, taken from ifcfg-eth0. Is there an easy way to fix this? Thanks for any advice.
# cat /etc/sysconfig/network NETWORKING=yes HOSTNAME=pbx.mysite.home gateway=192.168.200.1
# cat /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=eth0 BOOTPROTO=static IPADDR=192.168.200.11 BROADCAST=192.168.200.255 NETMASK=255.255.255.0 NETWORK=192.168.200.0 HWADDR=00:30:48:80:EE:0C ONBOOT=yes TYPE=Ethernet
On Monday 14 November 2005 02:25, Chris Mason (Lists) wrote:
Is there an easy way to fix this? Thanks for any advice.
# cat /etc/sysconfig/network NETWORKING=yes HOSTNAME=pbx.mysite.home gateway=192.168.200.1
Try putting GATEWAY in there in uppercase letters instead of lower case...
Peter.
"Chris Mason (Lists)" lists@masonc.com wrote:
I have a server running Centos4. I found I was seeing some network problems so I tried "route" and found there was no routing.
Also remember to use the "-n" option to turn off name service lookups. If you're on a private LAN without an internal DNS, it will cause route to seem to "hang."
Also consider "netstat -rn" instead of "route -n" for a variety of reasons on various UNIX platforms, including Linux.
I thought reboot would solve it but it didn't.
Consider "service network restart" before rebooting.
I had to manually enter a route to the default gateway, there is still no route to the loopback interface.
For the loopback to come up on Fedora-based distros, there must be a /etc/sysconfig/network-scripts/ifcfg-lo file (with properly configured entries).
How is this possible? I thought there was default routes built into the kernel,
Yes, the routing table is built into the kernel. And depending on the configuration, the kernel may or may not assign "default route" to subnets "local" to lo, eth0, etc... (i.e., metric 0 routes)
But no, the kernel _never_ sets a "default gateway" -- that is done in a platform's rc/system/init/whatever script. In Fedora-based distros, this is in either /etc/sysconfig/network or the relevant /etc/sysconfig/network-scripts/ifcfg-* file(s).
taken from ifcfg-eth0.
For a single NIC system, it can be in either /etc/sysconfig/network or /etc/sysconfig/network-scripts/ifcfg-eth0.
Is there an easy way to fix this? Thanks for any advice. # cat /etc/sysconfig/network NETWORKING=yes HOSTNAME=pbx.mysite.home gateway=192.168.200.1
Yes, make your "gateway" variable "GATEWAY". Bourne [Again] Shell ([ba]sh) variables have _always_ been case sensitive. Constants are almost always declared as upper-case c/o legacy C'isms.
# cat /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=eth0 BOOTPROTO=static IPADDR=192.168.200.11 BROADCAST=192.168.200.255 NETMASK=255.255.255.0 NETWORK=192.168.200.0 HWADDR=00:30:48:80:EE:0C ONBOOT=yes TYPE=Ethernet
You _should_ still have a route for 192.168.200.0/24 in your routing table. But that, of course, won't get you to the Internet. ;->
If "route" (or "netstat -r") are seemingly "hanging" for minutes, then you don't have DNS for your 192.168.200.0/24 network, and use the "-n" option.
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Bryan J. Smith -
Chris Mason (Lists) -
Peter Arremann