Blocked by STP procurve

[Blocked by STP]

Hello all,

I have a problem with some of my ProCurve ports being blocked by STP. Is there an explanation for this?


I 09/23/10 12:27:57 00077 ports: port 44 is now off-line
I 09/23/10 12:28:20 00435 ports: port 44 is Blocked by STP
I 09/23/10 12:28:23 00076 ports: port 44 is now on-line
I 09/23/10 12:28:32 00077 ports: port 44 is now off-line
I 09/23/10 12:28:39 00435 ports: port 44 is Blocked by STP
I 09/23/10 12:28:42 00076 ports: port 44 is now on-line
I 09/23/10 12:31:50 00435 ports: port 14 is Blocked by STP
I 09/23/10 12:31:53 00076 ports: port 14 is now on-line
I 09/23/10 12:32:16 00077 ports: port 14 is now off-line
I 09/23/10 12:32:29 00435 ports: port 14 is Blocked by STP
I 09/23/10 12:32:32 00076 ports: port 14 is now on-line
I 09/23/10 12:33:01 00077 ports: port 44 is now off-line
I 09/23/10 12:33:07 00435 ports: port 44 is Blocked by STP
I 09/23/10 12:33:09 00076 ports: port 44 is now on-line
I 09/23/10 12:33:47 00077 ports: port 44 is now off-line
I 09/23/10 12:33:58 00435 ports: port 44 is Blocked by STP
I 09/23/10 12:34:01 00076 ports: port 44 is now on-line
I 09/23/10 12:35:37 00077 ports: port 44 is now off-line
I 09/23/10 12:36:26 00435 ports: port 32 is Blocked by STP
I 09/23/10 12:36:29 00076 ports: port 32 is now on-line
I 09/23/10 12:37:32 00077 ports: port 32 is now off-line
I 09/23/10 12:38:01 00435 ports: port 29 is Blocked by STP
I 09/23/10 12:38:03 00076 ports: port 29 is now on-line
I 09/23/10 12:38:52 00077 ports: port 29 is now off-line
I 09/23/10 12:39:11 00435 ports: port 44 is Blocked by STP
I 09/23/10 12:39:14 00076 ports: port 44 is now on-line
I 09/23/10 12:40:36 00077 ports: port 44 is now off-line
I 09/23/10 12:41:12 00435 ports: port 2 is Blocked by STP
I 09/23/10 12:41:15 00076 ports: port 2 is now on-line
I 09/23/10 12:42:28 00077 ports: port 2 is now off-line
I 09/23/10 12:42:44 00435 ports: port 31 is Blocked by STP
I 09/23/10 12:42:45 00077 ports: port 31 is now off-line
I 09/23/10 12:42:47 00435 ports: port 31 is Blocked by STP
I 09/23/10 12:42:47 00077 ports: port 31 is now off-line
I 09/23/10 12:42:49 00435 ports: port 31 is Blocked by STP
I 09/23/10 12:42:49 00077 ports: port 31 is now off-line
I 09/23/10 12:42:51 00435 ports: port 31 is Blocked by STP
I 09/23/10 12:42:52 00077 ports: port 31 is now off-line
I 09/23/10 12:42:54 00435 ports: port 31 is Blocked by STP
I 09/23/10 12:42:54 00077 ports: port 31 is now off-line
I 09/23/10 12:42:56 00435 ports: port 31 is Blocked by STP
I 09/23/10 12:42:59 00076 ports: port 31 is now on-line
I 09/23/10 12:43:11 00077 ports: port 31 is now off-line
I 09/23/10 12:43:51 00435 ports: port 31 is Blocked by STP
I 09/23/10 12:43:52 00077 ports: port 31 is now off-line
I 09/23/10 12:43:54 00435 ports: port 31 is Blocked by STP
I 09/23/10 12:43:55 00077 ports: port 31 is now off-line
I 09/23/10 12:43:56 00435 ports: port 31 is Blocked by STP
I 09/23/10 12:43:57 00077 ports: port 31 is now off-line
I 09/23/10 12:43:59 00435 ports: port 31 is Blocked by STP
I 09/23/10 12:44:00 00077 ports: port 31 is now off-line
I 09/23/10 12:44:02 00435 ports: port 31 is Blocked by STP
I 09/23/10 12:44:02 00077 ports: port 31 is now off-line
I 09/23/10 12:44:04 00435 ports: port 31 is Blocked by STP
I 09/23/10 12:44:05 00077 ports: port 31 is now off-line
I 09/23/10 12:44:07 00435 ports: port 31 is Blocked by STP
I 09/23/10 12:44:09 00076 ports: port 31 is now on-line
I 09/23/10 12:46:31 00077 ports: port 45 is now off-line
I 09/23/10 12:46:38 00435 ports: port 45 is Blocked by STP
I 09/23/10 12:46:40 00076 ports: port 45 is now on-line

P.S. This thread has been moved from  Switches, Hubs, Modems (Legacy ITRC forum) to ProCurve / ProVision-Based. -HP Forum Moderator

[Mohammed Faiz]

Hi,

What devices are connected on those ports?

STP is the Spanning Tree Protocol which prevents loops on your network.
If you were not using STP and something created a loop on your network (either your resilient design or someone connecting the same cable to a swtich twice) then it would probably cause your network to stop working.

You need to find what devices are connected on those switch ports and determine whether the loop is valid.

[Pieter 't Hart]

in addition to Mohammeds post

All ports can potentially create a loop.
(think of two wall-outlets patched to one another!).

So When spanning-tree is enabled, potentially all ports need to participate in the spanning-tree protocol.
Even client ports!
Every client on/of/rebooot/connect/disconnect can produce such a message.

you need to specifically configure the port not to participate in spnning-tree operation.

You can disable logging these on/of events on these ports.

[Blocked by STP]

Strange that three days ago the ports of some end points were blocked and noes were causing the network loop.
Example the point that a printer was connected blocked alone, after shutdown end no shutdown the port returned UP.

[Mohammed Faiz]

Sorry, I was reading your log the wrong way around! (I'm used to doing a "show log -r" :) )
That is normal behaviour, whenever a port goes offline and comes back online you will see in your logs

- port X is now off-line
- port X is Blocked by STP
- port X is now on-line

That will happen even if you aren't running STP.

[Blocked by STP]

Ok! But see de log attached, port 2, 5 and 44, pleased!

[Pieter 't Hart]

- the switch has stp active
- a port comes up (=> the PC is switched on
)
- the switch does not know what's connected and if a loop has formed
- so it initially puts the port in the STP blocked state
I 09/20/10 11:30:53 00435 ports: port 2 is Blocked by STP
- goes through listening and learning states
- concludes there is no loop
- unblocks the port (port is now on-line)
I 09/20/10 11:30:55 00076 ports: port 2 is now on-line
- the PC is shut down for the night
I 09/20/10 17:43:48 00077 ports: port 2 is now off-line

This is normal behaviour

[Mohammed Faiz]

I think the sequence that is being referred to is this:

I 09/23/10 12:41:12 00435 ports: port 2 is Blocked by STP

I 09/23/10 12:41:15 00076 ports: port 2 is now on-line

I 09/23/10 12:42:28 00077 ports: port 2 is now off-line

The first two entries are normal as Pieter describes above.
The third entry occurs 45 seconds later which suggests to me that it's a client issue. There is also nothing in the logs to suggest that MSTP is disabling the port.
If you want to test that try disabling STP on that port and seeing if you still have an issue:

# spanning-tree 2 admin-edge-port

[Jromero40]

I have an issue with My AP's being blocked by STP. I work for a University and we have found in past instances that students will bridge thier NIC's (Wired and Wireless) thinking they will get faster connections. This is the reason we turned spanning tree on. Is there a way to make sure that the port with the AP always takes priority or that it never gets blocked?

[zuber_mansuri]

Hi,

i have the same error but "spanning-tree 12 admin-edge-port" does not solve. The port 12 on my setup is connected to VMWare device.