OS 11.4 no network connection after network re-configuration

English Network/Internet
1

Hi.

I have encountered weird behaviour on our linux server running OS 11.4 x86_64.

I have to switch the external interface of the server/firewall from one physical network to a newer one.
In each of these networks the server has a static IP address assigned by the IT department of the university.

A job simple enough:

  1. Change IP, Hostname and Gateway IP
  2. Plug the cable from the external interface into the appropriate connector and restart the network interface.

This failed. After a restart of the network the server does not see even the set gateway. (i.e. a ping returns HOST UNREACHABLE)

I have tried the setup on my laptop too (running OS 12.3 x86_64) Here everything worked - but required a restart.

Thus my question:
Have I missed something in the restart process?
My understanding is, that changing the settings(IP, Hstname,Gateway) in Yast should be sufficient but this seems not to have worked here.

N.B. I would like to avoid having to restart the server.

2

Well, you do not provide us which much facts.

Check if the NIC came up with the correct IP address and netmask:

/sbin/ifconfig -a

Check if you have the gateway configured correctly:

netstat -rn
3

Sorry, my bad.

I and a colleague sat down yesterday for another maintenance session and figured the problem out in the end.

The documentation of our network was erroneous, so when I changed the cables I plugged the internal network into the external one.