I have migrated 5 vms from SLES11 SP4 to SLES12 SP3 and now find that none of the vms can access the internet. 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?