I find this statement to be a bit ambiguous. Can I assume it means you didn’t upgrade or change any of the VMs but simply moved them from a SLES11 SP4 host to a new SLES12 SP3 host?
[QUOTE]They are a mixture of sles11sp4 oes2015 and win 12. All the setting are the same and I have used YAST to configure the SLES12 KVM server. All the vms can see each other and the gateway, but internet access through the gateway does not occur. The YAST settings for networking and bridging on the SLES12 server correspond to the SLES11 from which the vms were migrated, but where I could ping the external gateway from the vm computers on SLES11, this is prevented on the SLES system. Internet access on the SLES12 kvm server is fine.
Anyone have any ideas how to fix this?
I have highlighted what your issue appears to be and will try to offer a few suggestions but my systems are still on SLES11 SP4 and I haven’t had an opportunity to work with SLES12 so others are welcome to jump in.
Is this a new SLES12 installation or did you upgrade from SLES11?
From the information you provided, this appears to be a forwarding issue.
Have you enabled forwarding?
Is your firewall enabled?
The first thing I would do is check /var/log/messages for any clues then check your firewall settings. If you check /etc/sysconfig/SuSEfirewall2, it has all the firewall settings. You should be able to see if forwarding is enabled and just what might be forwarded.
Please report back what you learn.