Routing Global IP to F5-LTM

Have a dual datacentre environment and we're running F5 BIG-IP LTM for Load Balancing and GTM/DNS for Global Load Balancing.

 

I have an system which needs to operate across the two data centres Active/Failover (load-balanced by LTM within each DC) but must only present a single a single IP (only supports single IP) to be available and cannot support DNS resolution. So a single IP is hard coded into the source and needs to be able to access whichever load-balanced set of servers is active at either data centre 1 or 2.

 

The network architecture does not allow for NAT in front of the F5 platforms (e.g. I can't just configure network with a NAT that points the same IP to different VIPs).

 

My initial thought was as follows:

 

Configure the LTM VIP with two IP addresses (one local and one global) then configure the routers in front of the F5 with a static route to the global IP via the local IP which is redistributed into routing protocol so for example.

 

• DC1 LTM has a Virtual Server of 10.1.1.1 with secondary IP of 10.10.10.1
• DC2 LTM has a Virtual Server of 10.2.2.1 with secondary IP of 10.10.10.1
• DC1 Router has static route to 10.10.10.1 via 10.1.1.1
• DC2 Router has static route to 10.10.10.1 via 10.2.2.1

The Virtual Server on the LTM at DC2 would be disabled and therefore next hop wouldn't exist in router and thus all traffic would route to DC1 and be routed to the Virtual Server.

 

On failover, disable the LTM Virtual Server at DC1 and enable at DC2.

 

That would work for a normal server which can have multiple IPs but the LTM Virtual Server can't have more then one IP.

 

So next I thought that instead of using two IPs on a Virtual Server, configure it as follows:

 

• DC1 LTM Cluster has a Floating SelfIP of 10.1.1.1 with Virtual Server of 10.10.10.1
• DC2 LTM Cluster has a Floating SelfIP of 10.2.2.1 with Virtual Server of 10.10.10.1
• DC1 Router has static route to 10.10.10.1 via 10.1.1.1
• DC2 Router has static route to 10.10.10.1 via 10.2.2.1

But I can't find a way to enable or disable Self IP only add/delete so not such an easy method to enable or disable.

 

Any other thoughts or suggestions?