I over simplified my explanation because it makes me look bad. Here is the full breakdown if you are interested...

We are using a Brocade CER. Last night we upgraded from 5.5e to 5.6g.

Here is the syntax change as documented by RANCID:

  mac access-list BLOCKSPAN
-  deny any 0180.c200.0000 ffff.ffff.ffff any etype any
-  permit any any any etype any
+  sequence 10 deny any 0180.c200.0000 ffff.ffff.ffff any etype any
+  sequence 20 permit any any any etype any


That change happened automatically and worked fine. We had a separate (possibly unrelated) issue this morning and decided to rollback the code just in case. I wasn’t aware we were rolling back when I sent my query.

If I would have waited a few more minutes (or looked at the config more closely or talked to the engineer) RANCID would have told me the downgrade was not as graceful and just deleted the access-list:

- mac access-list BLOCKSPAN
-  sequence 10 deny any 0180.c200.0000 ffff.ffff.ffff any etype any
-  sequence 20 permit any any any etype any


Sorry for bothering everyone with our internal issue. In hindsight it was pretty obvious what happened. My only excuse is I am the only person in the office today because we got 14” of snow last night.

Thanks for all the help.
Dan

On 3/24/16, 10:36 AM, "MICE Discuss on behalf of Mike Horwath" <[log in to unmask] on behalf of [log in to unmask]> wrote:

>On Thu, Mar 24, 2016 at 03:26:33PM +0000, Dan Winkel wrote:
>> That was the case. A code upgrade last night changed the syntax of
>> the BPDU blocking code.
>
>What are you using that a change like this happens?
>
>Just wondering so I can get smarter.
>
>--
>Mike Horwath, reachable via [log in to unmask]