Forum Discussion

MW1's avatar
MW1
Icon for Cirrus rankCirrus
May 13, 2010

Switching from direct cable link HA to network linked HA

All,

 

I have a pair of F5 LTM's in active/passive HA mode using a directly connected cable between them which have been ticking away without issue. When I first installed them I tried to configure the HA to use the network link method however I did have issues with this (basically they appeared to loose knowledge of synch state quite quickly) so due to a short time frame decided to go for the direct cable link method. My company has several different caged areas and suites in our main data centre where the LTM's are kept, which are all on the same network thanks to fibre runs across the building. I've been asked to migrate the LTM's out of the current suite to a different suite, preferably without interupption to service. I'm therefore exploring the feasability of doing the following:

 

 

1) Switch from direct cable to network link HA connectivity

 

2) Move one LTM to the new suite and get this device back in to the HA active/passive group with the remaining one in the orginal suite

 

3) Failover to the LTM in the new suite

 

4) Move the final LTM to the new suite, get it in to the HA group & fail back over to make this the primary

 

 

To hamper my planning this is the only HA pair of LTM's my company owns so I don't have the ability to do a dry run on this - I was considering if trying to get a couple of the LTM VE trial lics (which I know states doesn't support HA but seen some posts saying they managed to get it working - this said not sure how much of a valid test this would give).

 

 

So my questions are:

 

 

1) Does anyone know if its possible to switch between the direct cable to network link HA connectivity without interupption to service?

 

2) As my manager has asked if we could run for a week between steps 3 & 4 (ie with the LTM's in different suites which are at totally different ends of the dc building ), does anyone have any experince of running LTM's in a HA pairs via a network link that is going through 3 or 4 different switches, and does this pose a major issue?

 

 

thanks in advance

 

 

Matt

 

config
design

1 Reply

Sort By
  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    May 18, 2010
    Hi MW,

     

     

    If you have a dedicated link (untrunked) between the two units which you use only for network failover, you could conceivably bring that up, set the new unit to standby and then bring up the other links/vlans without any downtime. You could try to do this with no downtime/effect on live traffic, but I would suggest scheduling a maintenance window anyhow.

     

     

    If there is no official support for HA in the virtual edition, I don't think it would be a valid test.

     

     

    Aaron