GitHub user SudharmaJain opened a pull request:
https://github.com/apache/cloudstack/pull/836
CLOUDSTACK-8863: VM doesn't reconnect to internet post VR RESTART/STOâ¦
â¦P-START/RECREATE
The ongoing ICMP request reply session is broken when the VR is down, the
expectation is that it would resume once the VR is up. Investigations revealed
that the ongoing ICMP packets are sent out of eth2 without being NATed post VR
stop/start or restart or recreate.
TCPDUMP output from VR post restart/stop-start/recreate on eth2:
root@r-4-VM:~# tcpdump -i eth2 icmp -n -vvv
tcpdump: listening on eth2, link-type EN10MB (Ethernet), capture size 65535
bytes
06:22:52.749770 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP
(1), length 84)
192.168.200.67 > 173.194.33.163: ICMP echo request, id 30996, seq 81,
length 64
06:22:53.749782 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP
(1), length 84)
192.168.200.67 > 173.194.33.163: ICMP echo request, id 30996, seq 82,
length 64
06:22:54.749771 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP
(1), length 84)
192.168.200.67 > 173.194.33.163: ICMP echo request, id 30996, seq 83,
length 64
06:22:55.749775 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP
(1), length 84)
192.168.200.67 > 173.194.33.163: ICMP echo request, id 30996, seq 84,
length 64
06:22:56.749765 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP
(1), length 84)
192.168.200.67 > 173.194.33.163: ICMP echo request, id 30996, seq 85,
length 64
06:22:57.749776 IP (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP
(1), length 84)
192.168.200.67 > 173.194.33.163: ICMP echo request, id 30996, seq 86,
length 64
^C
6 packets captured
6 packets received by filter
0 packets dropped by kernel
root@r-4-VM:~#
root@r-4-VM:~# grep icmp /proc/net/ip_conntrack
icmp 1 29 src=192.168.200.67 dst=173.194.33.163 type=8 code=0 id=30996
[UNREPLIED] src=173.194.33.163 dst=192.168.200.67 type=0 code=0 id=30996 mark=0
use=2
This get fixed after flushing the conntrack table.
Screenshots:
Before fix (ping session doesn't resume, stop and starting the ping works,
120 packets lost):

After fix(ping session resumes, 27 packets lost):

You can merge this pull request into a Git repository by running:
$ git pull https://github.com/SudharmaJain/cloudstack cs-8863
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/cloudstack/pull/836.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #836
----
commit 321bba79579eab9cd59a1697a2d4b0ff6ae54bec
Author: sudharma jain <[email protected]>
Date: 2015-09-16T05:25:57Z
CLOUDSTACK-8863: VM doesn't reconnect to internet post VR
RESTART/STOP-START/RECREATE
----
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