Single IP unreachable after suspend
The following issue occured several times over the last month with Ubuntu 11.10 x86_64, kernel 3.0.0-16-generic.
It happened from the beginning (3.0.0-15). I didn't have this Computer before, so I don't know if the issue is specific to this Ubuntu / kernel version.
Sometimes, after waking up from suspend, single remote hosts are not reachable. It may be the first host the system tries to connect to (or may be the last one connected to before susped), but I'm not sure about that.
"not reachable" means there's no route. It's not a DNS issue because trying to ping the IP itself also fails. Example ping output:
$ ping 126.96.36.199
PING 188.8.131.52 (184.108.40.206) 56(84) bytes of data.
From 220.127.116.11 icmp_seq=1 Destination Host Unreachable
at the same time:
$ ping google.com
PING google.com (18.104.22.168) 56(84) bytes of data.
64 bytes from fra07s07-
here, 22.214.171.124 is my own IP in this network.
The destination IP is definitely reachable, I can reach it at the same moment on a different machine in the same network. Or from my own machine if I first ssh to another machine and connect from there.
The issue is hardly a network interface driver issue, because this already happened with both WiFi and Ethernet connection.
It looks like the issue doesn't happen in all networks. In my home network it didn't happen yet, but already in two other networks. I don't know what makes the difference.
As I said, the issue is isolated to single destination hosts. At the same time, the connection works normally for all other destinations.
I could solve this only by reboot up to now. Things I tried:
- restart networking
- suspend / wakeup again
- disconnect / reconnect network interface
- switch network interface (WiFi / Ethernet)
- ip route flush cache
- ip neigh flush all
I am no networking expert, but a sysadmin of the university network took a look at my Computer when the issue appeared. He couldn't find out the reason, but suspected it to be a kernel issue.
I think the posting at http://
For any further advice on how I could gather more useful information / try to fix it I would be very helpful.
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
**** List of CAPTURE Hardware Devices ****
card 0: Intel [HDA Intel], device 0: CONEXANT Analog [CONEXANT Analog]
Subdevice #0: subdevice #0
USER PID ACCESS COMMAND
/dev/snd/pcmC0D0p: didi 6739 F...m pulseaudio
CRDA: Error: [Errno 2] Datei oder Verzeichnis nicht gefunden
Card hw:0 'Intel'/'HDA Intel at 0xf2520000 irq 43'
Mixer name : 'Intel IbexPeak HDMI'
Components : 'HDA:14f15069,
Controls : 12
Simple ctrls : 6
Card hw:29 'ThinkPadEC'
Mixer name : 'ThinkPad EC 6UHT32WW-1.13'
Components : ''
Controls : 1
Simple ctrls : 1
Simple mixer control 'Console',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [on]
DistroRelease: Ubuntu 11.10
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
MachineType: LENOVO 29124NG
Package: linux (not installed)
Tags: oneiric staging
Uname: Linux 3.0.0-16-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm admin cdrom davfs2 dialout lpadmin plugdev sambashare
dmi.bios.version: 6UET64WW (1.44 )
dmi.board.version: Not Available