Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

no spanning-tree optimize bpdu transmission

What is "spanning-tree optimize bpdu transmission". I have this in a bunch of my switches and haven't found a good reference for it. TIA.

-John

2 ACCEPTED SOLUTIONS

Accepted Solutions
Hall of Fame Super Bronze

Re: no spanning-tree optimize bpdu transmission

Check Bug CSCee70806 at

http://www.cisco.com/cgi-bin/Support/Bugtool/launch_bugtool.pl

____________________

Release Notes

"no spanning-tree optimize bpdu transmission" cannot be removed from the "show running" output.

No workaround available

_________________________

Fixed-in Version: 12.2(25)SE

Hall of Fame Super Bronze

Re: no spanning-tree optimize bpdu transmission

The cool feature is that it optimizes bpdu transmission as the name states. However, when enabled it causes high CPU utilization since it runs in software, not hardware.

Cisco decided to disable this feature and hide it from the config. I guess some releases did not hide the command hence a bug was entered against it.

8 REPLIES
Hall of Fame Super Bronze

Re: no spanning-tree optimize bpdu transmission

Basically, this command shouldn't be seen in the config and the 'no' option should be removed. It's a bug in the IOS, what platform are you running ?

New Member

Re: no spanning-tree optimize bpdu transmission

I have it on 3750s and 2955s. I am running 12.2(various).

Hall of Fame Super Bronze

Re: no spanning-tree optimize bpdu transmission

Check Bug CSCee70806 at

http://www.cisco.com/cgi-bin/Support/Bugtool/launch_bugtool.pl

____________________

Release Notes

"no spanning-tree optimize bpdu transmission" cannot be removed from the "show running" output.

No workaround available

_________________________

Fixed-in Version: 12.2(25)SE

New Member

Re: no spanning-tree optimize bpdu transmission

I thought there might have been a cool feature I wasn't aware of. Oh well. Thanks.

Hall of Fame Super Bronze

Re: no spanning-tree optimize bpdu transmission

The cool feature is that it optimizes bpdu transmission as the name states. However, when enabled it causes high CPU utilization since it runs in software, not hardware.

Cisco decided to disable this feature and hide it from the config. I guess some releases did not hide the command hence a bug was entered against it.

Re: no spanning-tree optimize bpdu transmission

Edison,

Can you elaborate more on this? In older versions of 3750 code "no spanning-tree optimize bpdu transmission" showed up in the config and could not be changed. With new versions 12.2(25)SEE3 and 12.2(35)SE5, if you do a "write erase" and reload, the command is missing from the config meaning it's entered and on by default. Now where I'm confused is if I do a "default spanning-tree optimize bpdu transmission", the command shows up as no spanning-tree optimize bpdu transmission, like the older code.

So moving forward should it be "spanning-tree optimize bpdu transmission" or "no spanning-tree optimize bpdu transmission"? From your previous post you indicated it could cause high CPU utilization, so it should be turned off with "no spanning-tree optimize bpdu transmission"? I'm I understanding this correctly?

Re: no spanning-tree optimize bpdu transmission

Edison, - Need your help on this one...

Hall of Fame Super Bronze

Re: no spanning-tree optimize bpdu transmission

You are correct and the command should be hidden in the config as its the default value is "no spanning-tree optimize bpdu transmission".

The fact the command can be seen, it's a cosmetic bug.

HTH,

__

Edison.

27211
Views
5
Helpful
8
Replies