connect: Network is unreachable - issue after upgrade of network/firewall mod

[shahdivy]

Performed Component updates -  Network/Firewall modules on April 10,2017 which was successful.  After that tried performing rest of updates which were failing.

Checked log  /var/log/zentyal/zentyal.log file to find errors -

2017/04/10 22:20:09 ERROR> install-packages:94 main:: - Failed to fetch http://security.ubuntu.com/ubuntu/pool/main/g/glibc/multiarch-support_2.23-0ubuntu7_amd64.deb  Cannot initiate the connection to us.archive.ubuntu.com:80 (91.189.91.26). - connect (101: Network is unreachable) [IP: 91.189.91.26 80]

Traceroute also gave same error:

#traceroute yahoo.com
traceroute to yahoo.com (98.138.253.109), 30 hops max, 60 byte packets
connect: Network is unreachable

Issue: After component upgrade, routing to external network broke. 

I have performed same upgrade on another system which did not have issue.!

[shahdivy]

Update:

Was able to fix issue of routing to internet by  selecting External (WAN) box in

Network -> Interfaces section.

But this broke local access to the server - SSH or DNS did not work.

After I finished update, I had to uncheck box to get it working!!  Strange issue as other servers are working fine without checking box.

More info on server:

It has 2 interfaces as follows:

bksdadmin@amddc02:~$ netstat -nr
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
172.16.16.0     0.0.0.0         255.255.255.0   U         0 0          0 eno1
172.16.17.0     0.0.0.0         255.255.255.0   U         0 0          0 enp1s10
bksdadmin@amddc02:~$

Selected external WAN box for en01 to get external routing working.  Yes there is no default gateway but it works!  Not sure how zentyal is managing default gateways.

Still doing investigating more on this issue.

[shahdivy]

Following older article - https://forum.zentyal.org/index.php?topic=21190.0

Added gateway in /etc/network/interfaces file
/etc/init.d/networking restart

Now I am able to route traffic to Internet and local network works as well.

[shahdivy]

Update:

Looks like /etc/network/interfaces file gets overwritten when server is rebooted..   Need to figure out permanent fix..