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Subject [2/2] git commit: updated refs/heads/master to c9985e9
Date Fri, 11 Dec 2015 18:42:55 GMT
Merge pull request #1214 from remibergsma/rfc1918_route

CLOUDSTACK-9143 Setup routes for RFC 1918 ip spaceSetup general route for RFC 1918 space,
as otherwise it will be sent to the public gateway and likely to be dropped (internet providers
do not route ip space that is meant for internal use). More specific routes that may be set
have preference over this generic routes so this works even with private ranges used for public
ip space (as shown below).

When using an internal DNS server some hosts may resolve to an RFC 1918 ip address. The SSVM
has a default gw to public so if it has no route for this ip address space, it will not work.
This PR makes generic RFC 1918 (so all internal ip adresses like etc) to the local
management gateway. This makes them reachable. Without this fix, it is sent upstream and it
is dropped there.

Should there be a more generic route (smaller prefix), this has preference over the generic

Example in my dev environment:

root@v-1-VM:~# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface         UG    0      0        0 eth2       UG    0      0        0 eth1     U     0      0        0 eth0     UG    0      0        0 eth1     UG    0      0        0 eth1   U     0      0        0 eth1   U     0      0        0 eth2

Route `` goes via `eth1` but `` is more specific and has preference
and goes via `eth2`. It works:

root@v-1-VM:~# ping
PING ( 48 data bytes
56 bytes from icmp_seq=0 ttl=49 time=7.179 ms
^C--- ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max/stddev = 7.179/7.179/7.179/0.000 ms

This solves a lot of the 'internal resolving' issues we face.

When the public ip address is RFC1918 itself, we do not set the routes.

* pr/1214:
  Setup routes for RFC 1918 ip space

Signed-off-by: Remi Bergsma <>


Branch: refs/heads/master
Commit: c9985e96a5446395f402faccd422935d24b7c933
Parents: 1ed5c20 67b4a7b
Author: Remi Bergsma <>
Authored: Fri Dec 11 19:42:36 2015 +0100
Committer: Remi Bergsma <>
Committed: Fri Dec 11 19:42:36 2015 +0100

 .../debian/config/etc/init.d/cloud-early-config    | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

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