Speaking at Raona SharePoint Day on 2nd October in London

I’m speaking on Business Intelligence and SharePoint at the Raona SharePoint day on 2nd October. You can follow Raona on Twitter for news

With demos of Vodafone, Telefonica and Ecoembes, it will be good to see SharePoint in action. Sometimes people need examples so that they can see what to do with technology, and to spark ideas. I don’t think that’s a bad thing; technology is essentially a creative process, so why not take a look at what others have been trailblazing in the field.

If you’d like to register, here is the link and I hope to see you there.

IP address query selection for High Availability Listener

One of my customers contacted me; they had set up High Availability but had a concern. They couldn’t ping all of the IP addresses associated with each of their listeners.

I gave it a go, and sure enough, I could see one of the IP addresses, but not the ‘sleeping’ one, which was on a different subnet. The listener had two IP addresses, one for each subnet.
Then it suddenly made sense that this is ‘by design’. The IP addresses are not online at the same time, since the server can’t host an IP address that’s not in its subnet, so you can only have one ‘up’ at a time.
When the cluster group is owned by one of the nodes, one IP address is up. The other is down, sleeping but ‘healthy’.  When the cluster group is owned by the other node, the original ‘sleeping’ IP Address is up, and the original IP address is down.
This was easy enough to show. I induced failover, and then bringing it back up again. It is possible to see the swapover of the IP addresses, and the original ‘awake’ IP address going offline whilst the other comes up. 
It is still there; just not accessible since the server can’t host an IP address which is not part of its subnet.