A couple of possibilities to consider:
- use a private network (or perhaps even just an Ethernet crossover cable) between the systems to ssh into the unreachable system to perform an ifdown.
- have the surviving system access an external console / pdu to remove power from the unreachable system (stonith - shoot the other node in the head).

-Keith.
On May 1, 2014, at 11:31 AM, CS_DBA <[log in to unmask]> wrote:

> Hi All;
> 
> we have a failover tool (for a database) that pings te master and if it's not responding runs ifdown over ssh to bring an ip alias down, then runs ifup of the alias on the standby node.
> 
> A possible issue would be if the master was not reachable, thus the ifdown fails and once the master becomes available again then we have 2 nodes with the ip alias and we risk a split brain issue
> 
> Is there a way to disable any traffic from getting to the old master via commands we can run outside of the master server?
> 
> Thanks in advance