Forum Discussion

Lee_Sutcliffe's avatar
Jun 21, 2011

Active/Active DC design considerations - Without DNS



We're going through a DC migration at the moment and just in the high level planning stages.


Here's our question:




We can failover a DC or run them active/active using GTMs for Internet facing traffic.


However we have some larger clients who use our private MPLS for dedicated and secure access to our products.


These customers do not use DNS on the WAN, they target an IP (albeit with a hostname or using their local DNS servers)


Running DNS on the WAN is not feasible.


What options are available to provide site resiliency with GTM/LTM when DNS is not available?


1 Reply

  • you have a lot of different options to achieve an active active design when your customers are targeting an ip address,


    so you need to provide with some more information,


    how will the you connect the two data centers?


    are they going to be l2 or l3 connected? will they have shared segments ?


    how do you advertise your external prefix to the internet ?


    does the target ip address is currently a vip or a server?



    when you are targeting an ip address you will use ltm, if you are planning some kind of l2 extention between the sites


    you can just install a box at each site and configure it as active/passive, then you need to control the prefix advertisment


    and for that you have lots of ways too (mostly done on the external routers)