Symptoms

A virtual machine gets migrated online from a node with Virtuozzo 6.0 Update 10 (or earlier) to a node with Update 11 (or later). The VM contains 2 network interfaces, the secondary one being a routed adapter, a typical configuration in OACI environment.

As a result, a virtual machine loses network connectivity on private network, which is configured on the network adapter in routed mode.

The IP address assigned to the corresponding vme* interface on the hardware node changed from 169.255.30.1 to 169.254.0.1, but the route inside the VM didn't reflect the change:

root@test:/# ip r l
169.255.30.1 dev eth3  scope link

Cause

Virtuozzo 6.0 Update 11 brings a change to the default gateway for routed adapters to comply with the APIPA standard address range change in scope of RFC-3927. During online migration, no network reconfiguration occurs inside the VM, so the new route is not present.

Resolution

In order to bring the VM connectivity back, two options are possible:

  • add the needed route manually in the VM:

    Linux:

    # ip route add 169.254.0.1 dev eth3 scope link

    where "eth3" is the actual name of the interface that can be found from the output of ip a command.

    Windows:

    route add -P 169.254.0.1 mask 255.255.255.255 169.254.0.1 if <ID>

    where is the ID of the routed interface that can be found from the output of route print command.

  • (or) restart the VM

It is also recommended to update guest tools inside the virtual machine to correct the issue:

Linux Guest Tools update instructions
Windows Guest Tools update instructions

Additional Information

Reference links:
Virtuozzo 6.0 Update 11
Understanding of Routed Mode

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