I learned an interesting thing about the Config Sync process the other day and I wanted to share the story with others in the community.  I was on a BIG-IP 6400 unit that was the Active unit in an Active/Standby pair, just doing some pre-spring cleaning (I bet there are some Network Support Engineers shaking their head right about now) and decided I needed to clear out all of the old expired SSL certificates out of the certificate store on the unit.

No problem, I identified all of the expired certificates, checked the box beside them and hit the delete button at the bottom of the page.  After verifying everything was still happy and the support tickets didn’t start flooding my inbox I decided to run a config sync and push the config changes over to the standby box.

The config sync ran without a problem and the gui showed Config Sync: OK.  I then proceeded to check my changes on the standby unit, just for verification purposes.  And that ladies and gentlemen, is when the fun began….

As I was verifying the changes I noticed something I thought was rather strange.  The old SSL certificates that I deleted on the Active unit, were still there in the Standby units SSL Certificate store!  My first thought, oops, my Trusted Device Certificates must be out of whack.  I then proceeded to delete the trusted device certs and ran the “big_ip add” command from the CLI on each unit.  I checked my trusted device certificates and like magic there they were.  I ran another Config Sync thinking that probably fixed the problem, but wait… no such luck.

The Config Sync ran and didn’t kick out any errors, but the old SSL certificates were still in there in all their expired glory.  Frustrated and humbled once again, I decided to run a quick test by deleting a VS on the Active Unit to see if it would be removed once I ran a Config Sync.  I blew away the VIP I use for testing and ran the Config Sync again.  The VS was deleted off of the Standby Unit.  Not knowing off the top of my head what to do next, I then proceeded to open a ticket with my good friends over at F5 Networks.  I didn’t have a lot of faith in my running configuration at the time so I went ahead and opened the ticket as a level 2 ticket (site at risk).

I quickly received a phone call from a Network Support Engineer named Kevin “CB” Midkiff.  We went through the standard procedure of qkview files and few other tests.  After going over the problem Mr. Midkiff proceeded to explain to me that while the SSL Certificates store is indeed carried over when you run a Config Sync IT DOES NOT DELETE SSL Certificates on the unit that you push the config to.  In my case it was the Standby Unit.  The Config Sync function only appends SSL Certificates.

Moral to the story?  If you are double checking your configurations and happen to see some lingering SSL certificates don’t worry, just select them and let the delete button work its magic on them.  Also as an FYI, “CB” was great to work with and very knowledgeable.  Thanks again for your help Mr. Midkiff.


3 comments so far

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  1. Thanks for this tidbit of information, I was running into the same thing – was driving me nuts. I was thinking the certs weren’t being copied over at all, once I saw this article I double checked and yup, they are there – along with a whole bunch of others that were deleted from the active node.

  2. In 11.3 this behavior is changed. SSL cert can be delete when sync. :)

  3. Hi,

    Can we move SSL certs and keys of one unit (failed) to an other unit (replacement).