about STP in switch 5406zl ?

[MohammadH]

Hello

i have problem with STP it block port in the switch 5406zl and i pretty sure there no loop only one cable coming from that site i don't now why it black i see in the log the next line over and over 

I 08/06/14 10:20:58 00435 ports: port A9 is Blocked by STP
I 08/06/14 10:20:58 00077 ports: port A9 is now off-line
I 08/06/14 10:21:00 00435 ports: port A9 is Blocked by STP
I 08/06/14 10:21:00 00077 ports: port A9 is now off-line
I 08/06/14 10:21:01 00435 ports: port A9 is Blocked by STP
I 08/06/14 10:21:02 00077 ports: port A9 is now off-line
I 08/06/14 10:21:06 00435 ports: port A9 is Blocked by STP
I 08/06/14 10:21:06 00077 ports: port A9 is now off-line
I 08/06/14 10:21:08 00435 ports: port A9 is Blocked by STP
W 08/06/14 10:21:08 02672 FFI: port A9-Excessive link state transitions
I 08/06/14 10:21:08 00077 ports: port A9 is now off-line
I 08/06/14 10:21:15 00435 ports: port A9 is Blocked by STP
I 08/06/14 10:21:15 00077 ports: port A9 is now off-line
I 08/06/14 10:21:20 00435 ports: port A9 is Blocked by STP
I 08/06/14 10:21:20 00077 ports: port A9 is now off-line

i read about the wrang log in this link 

http://h20565.www2.hp.com/portal/site/hpsc/template.PAGE/public/psi/mostViewedDisplay?javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken&javax.portlet.prp_efb5c0793523e51970c8fa22b053ce01=wsrp-navigationalState%3DdocId%253Demr_na-c03043497-1%257CdocLocale%253Den_US&javax.portlet.tpst=efb5c0793523e51970c8fa22b053ce01&sp4ts.oid=3901668&ac.admitted=140...

we don't change anything in configure or the the fiber link .

thank you

[Vince-Whirlwind]

Nothing to do with STP.

You have a port resetting itself over and over again - maybe investigate the link or the remote device?

[MohammadH]

thank you Vince-Whirlwind for replay fast,

yest i check the link and is ok and the remote device to everything ok by hte way the remote device is switch 4800G.

i don't know what to do ?

[Vince-Whirlwind]

I don't think it's true that "everything ok" if you have a switchport flapping like that.

A few things I might play with are:

Compare the configuration of the switchports on either side of the link. Are they the same?

Make sure LLDP is enabled. do a "sh lldp neigh" on each switch. What do they both see?

Change both switchports to 100Mb. Does anything change?

[Richard Brodie_1]

In addition: look at logs on the other switch, see if there is a more useful message logged there. Swap around things systematically: try adding small unmanaged switch at one or other of other ends of the cable, see which end flaps then. And replace the cables, of course. Take notes as you go.

Good luck.

[MohammadH]

Thank you for your help

we fix the Problem it the problem was from media converter fiber.

thank you again.