Hi All,
I am facing a problem ( ???, maybe it works that way, but i really dont
know ) with regards to routing table behavior when using ifconfig on a
network interface.
1) netstat -nr Shows my default gateway for network 0.0.0.0
2) ifconfig eth0 down
3) netstat -nr No entry for the default gateway is shown (
understandable )
4) ifconfig eth0 up
After the the 4'th command, my interface is up and has it's IP address set
correctly. But .....
netstat -nr does not show my default gateway for network 0.0.0.0 !!.
Pinging any IP outside of my subnet, results in "Network is unreachable"
error.
Is is meant to be that way ? or is there a problem here ?
I've tried it on kernel versions, 2.4.0, 2.4.5 & 2.4.15
FYI : This has been tried using both DHCP and Static IP.
Thanks in advance !
Regards,
Raj
"Rajasekhar Inguva" <[email protected]> writes:
> Hi All, In continuation to my earlier report ...
>
> The problem is only seen with the default gateway entry.
>
> The gateway entry for my subnet is also deleted during a 'down', but is
> restored properly after an 'up' .
The default gateway route is installed at boot time by a separate
'route' command. 'ifconfig' can derive your subnet route from the
address and mask of the interface, but it can't magically determine
your default gateway. Add it yourself using "route" or "ip" or rerun
your network start scripts.
In short, "Working as Designed".
-Doug
--
Let us cross over the river, and rest under the shade of the trees.
--T. J. Jackson, 1863
Use the ifdown and ifup commands instead .. your default routes will
return
read the scripts in /etc/sysconfig/network-scripts/ for more info.
Madhav Diwan
Doug McNaught wrote:
>
> "Rajasekhar Inguva" <[email protected]> writes:
>
> > Hi All, In continuation to my earlier report ...
> >
> > The problem is only seen with the default gateway entry.
> >
> > The gateway entry for my subnet is also deleted during a 'down', but is
> > restored properly after an 'up' .
>
> The default gateway route is installed at boot time by a separate
> 'route' command. 'ifconfig' can derive your subnet route from the
> address and mask of the interface, but it can't magically determine
> your default gateway. Add it yourself using "route" or "ip" or rerun
> your network start scripts.
>
> In short, "Working as Designed".
>
> -Doug
> --
> Let us cross over the river, and rest under the shade of the trees.
> --T. J. Jackson, 1863
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
On Sat, 29 Dec 2001, Rajasekhar Inguva wrote:
> 4) ifconfig eth0 up
>
> After the the 4'th command, my interface is up and has it's IP address set
> correctly. But .....
>
> netstat -nr does not show my default gateway for network 0.0.0.0 !!.
ifconfig just brings the interface up, it does not set the routes. It is
not a kernel problem.
Usually, an interface is brought up by the /sbin/ifup (or
/etc/sysconfig/network-scripts/ifup) script which calls ifconfig and then
adds the default route by calling /sbin/route.
--
Catalin
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Hi,
Add the following line in the /etc/rc.d/init.d/network script at the end
of "start" case:
/sbin/route add default gw <whatever is your default getway ip address>
OR
You can modify the /etc/sysconfig/network-scripts/ifcfg-eth* to add a
line as
GW=<whatever is your default getway ip address>
and modify the /etc/rc.d/init.d/network script if statement at the end of
"start" case. For example, here are few lines of what I've done in my script:
# Add non interface-specific static-routes.
if [ -f /etc/sysconfig/static-routes ]; then
grep "^any" /etc/sysconfig/static-routes | while read ignore type
dest netmask mask gw gateway; do
[ "${gateway}" != "${gateway##[0-9}" ] && \
/sbin/route add -$type $dest $netmask $mask $gw $gateway
done
fi
touch /var/lock/subsys/network
;;
best of luck!
dipak
Rajasekhar Inguva wrote:
> Hi All,
>
> I am facing a problem ( ???, maybe it works that way, but i really dont
> know ) with regards to routing table behavior when using ifconfig on a
> network interface.
>
> 1) netstat -nr Shows my default gateway for network 0.0.0.0
>
> 2) ifconfig eth0 down
>
> 3) netstat -nr No entry for the default gateway is shown (
> understandable )
>
> 4) ifconfig eth0 up
>
> After the the 4'th command, my interface is up and has it's IP address set
> correctly. But .....
>
> netstat -nr does not show my default gateway for network 0.0.0.0 !!.
> Pinging any IP outside of my subnet, results in "Network is unreachable"
> error.
>
> Is is meant to be that way ? or is there a problem here ?
>
> I've tried it on kernel versions, 2.4.0, 2.4.5 & 2.4.15
>
> FYI : This has been tried using both DHCP and Static IP.
>
> Thanks in advance !
>
> Regards,
>
> Raj
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
Hi All, In continuation to my earlier report ...
The problem is only seen with the default gateway entry.
The gateway entry for my subnet is also deleted during a 'down', but is
restored properly after an 'up' .
Thanx,
Raj