Linode Forum
https://forum.linode.com/

Network unreachable - After VPS went down
https://forum.linode.com/viewtopic.php?f=19&t=6918		 Page 1 of 1
Author:  Entity_Razer [ Mon Apr 04, 2011 5:28 pm ]
Post subject:  Network unreachable - After VPS went down
Okidoki :) So I had a issue with my linode this morning, restarted Linode, no avail. Network wouldn't come up and remote access was out of the question.

I then proceeded to restore my Weekly backup and see if that one would come up ok. Unfortionatly this didn't help neither.

Since neither eth0 nor lo interfaces where comming up automatically (set to DHCP) I configured my interface as follows:


Code:
auto lo
iface lo inet loopback

auto eth0

iface eth0 inet static
address 109.74.194.xxx
netmask 255.255.255.0
gateway 109.74.194.1


this followed by a /etc/init.d/networking restart did nothing

If I try pinging the linode gateway (as shown on my "remote access" tab) I simply get
Code:
connect: Network is unreachable



Anyone care to shed some light on this issue please ?

regards,
Author:  caker [ Mon Apr 04, 2011 5:33 pm ]
Post subject: 
I've found that restarting networking using distribution init scripts on an already-configured interface is unreliable. Either reboot, or ifconfig the interface directly (but you still want to reboot to make sure it works on boot).

If that still fails, next thing to check is for any iptable rules.

-Chris
Author:  Entity_Razer [ Mon Apr 04, 2011 5:37 pm ]
Post subject: 
no new IPTABLE rules where added.

I rebooted the linode and none of the interfaces came up on their own.

I've already got a support ticket upen as well though.

edding:

kern.log messages I'm getting is:

eth0: no IPv6 Routers present

when bringing the interface up.

Nothing else is syslog, messages or otherwise that I know off.
Author:  caker [ Mon Apr 04, 2011 5:56 pm ]
Post subject: 
Code:
ifconfig eth0 109.74.194.xxx netmask 255.255.255.0 up
route add default gw 109.74.194.1

If that doesn't restore connectivity, it's very likely your iptable rules.

-Chris
Author:  Entity_Razer [ Mon Apr 04, 2011 5:59 pm ]
Post subject: 
yup,

that did it.

care to enlighten me whats different from you doing it and what I have in my config ? the only difference I could see is the route, but shouldn't that "automatically" be discovered ?
Author:  caker [ Mon Apr 04, 2011 6:08 pm ]
Post subject: 
Entity_Razer wrote:
care to enlighten me whats different from you doing it and what I have in my config ? the only difference I could see is the route, but shouldn't that "automatically" be discovered ?

Nope, not in ipv4 (at least by default). The "gateway 109.74.194.1" line in your /etc/network/interfaces and the associated init scripts should have taken care of this for you. Are you sure the default route wasn't already there?

Since this worked, the problem is in your configuration - I'd guess /etc/network/interfaces, or how it's being invoked, needs further scrutiny.

Glad I could help.
-Chris
Author:  SeaborneClink [ Sun Apr 10, 2011 2:39 am ]
Post subject: 
I too am having this issue. Having just done a dist-upgrade from lenny to squeeze I figured it was something to do with the packages or the kernel update that was involved. But this sounds exactly like what happened to me.

/etc/network/interfaces
Code:
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp


Have to manually bring the interface up and invoke dhclient
Code:
ifconfig eth0 up; dhclient eth0


and then everything works fine. I don't know what caused this, for me or for Entity_Razer, it doesn't sound like he made any system wide changes that would have caused this, and I don't reject that my dist-upgrade could have caused something to go pear shaped but this is too similar for me to discount both cases being related.

Edit: Ended up changing /etc/network/interfaces
Code:
auto eth0

to
Code:
allow-hotplug eth0


and then adding
Code:
dhclient eth0

to /etc/rc.local
Page 1 of 1 All times are UTC-04:00
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/