Forum Discussion
AltostratusGTM load balancing between two IP's, but one physical box
I think I know the answer to this, but I would like to confirm with the community.
Here is the scenario:
I have two datacenters. One of the application teams have one physical server in datacenter A, and no physical presence in datacenter B. They have an IP address pointing to datacenter A, and another IP pointing to datacenter B. Each IP for each datacenter is on different subnets.
They want to perform a disaster recovery test in this fashion:
- In the event of a failover, they want to change the IP address of the physical server in datacenter A to an IP address that lives in datacenter B.
- Then they'll change DNS to point to the datacenter B address.
Best practice would be to configure two pools (one for each datacenter) for the URL on the GTM and use Global Availability to send traffic to the next available pool.
My question is if I configure a pool for each datacenter and add both to the wide IP; and they change the IP address of the physical server; Will the GTM be able to send traffic to the same server, but with the other IP address?
They are in the planning phase of establishing a physical presence in datacenter B, but that's far into the future.
Thank you all for your help.
4 Replies
HamishCirrocumulus
Huh?
How do they plan on the DR address (That belongs in DC B) getting traffic routed to it when they configure it in DC A?
Or have I missed something here? Yes, I noticed it's a test, or I would have brought up the fact that doing DR to the same site isn't actually DR :)
Note that apart from monitoring of non-bigip servers... GTM doesn't 'send' traffic to servers at all... I'm also a bit confused by you asking about GTM and then stating they'll change DNS... GTM is all about providing a dynamic address resolution capability that depends on availability of target IP's...
Best practice would be to configure two pools (one for each datacenter) for the URL on the GTM and use Global Availability to send traffic to the next available pool.
Ahh... Kind of... Being a little pedantic GTM doesn't give a hoot about the URL. GTM cares about the FQDN portion of the URL to IP address resolution. The highly available FQDN is referred to as the WideIP on GTM (Not sure I 100% like the terminology, but at least it's unique & kind of catchy :) )
But yes, to use GTM, you'd configure two pools. One for DC A and one for DC B then configure the algorithm for the WideIP to Global Availability (Which selects the pools in order listed, based on whether they're up or not. Pool A will get all the traffic unless it's down, in which case poolB gets it).
H
RandyTittlemanThank you Hamish for your answer. I just wanted to make sure I wasn't going crazy.
- Hamish
Well, I won't guarantee that bit :)
However you don't sound completely mad
H
Stanislas_Piro2Cumulonimbus
Hi,
You can configure both pools, and create all the configuration for both datacenter
- VLAN + Self DC1
- VLAN + Self DC2
- Listeners DC1 & DC2
- Links DC1 & DC2
- Servers + VS DC1 & DC2
- Pool containing VS DC1 & DC2
If only DC1 link available, only DC1 pool members are answered
When you move GTM on DC2, Link DC2 become available, only DC2 pool members are answered
but it is really a strange DR! a simple Bind on both sites will do the same.
