08-28-2012 12:14 PM - edited 03-07-2019 08:34 AM
Hi all,
Recently, I had a topology change in my network enviroment comming from a switchport access port.
This port is configured with spanning-tree portfast command.
I assume that a switch never generates a TCN when a port configured for portfast goes up or down.
Switch says: Number of topology changes 212 last change occurred 07:37:33 ago from GigabitEthernet0/33
My switch port:
interface GigabitEthernet0/33
switchport access vlan 18
switchport mode access
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
queue-set 2
mls qos trust cos
no snmp trap link-status
auto qos voip trust
spanning-tree portfast
Is that a normal behavior? What can be a possible issue?
Thank you
08-28-2012 12:55 PM
Hi,
you're correct a Portfast port will not send any TCN but did you verify you port is indeed in Portfast mode ?
Show spanning-tree interface g0/33 will tell you so.
Regards.
Alain
Don't forget to rate helpful posts.
08-28-2012 01:02 PM
Here bellow:
#sh spanning-tree interface gigabitEthernet 0/33
Vlan Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
VLAN0060 Desg FWD 4 128.34 Edge P2p
#sh run interface gigabitEthernet 0/33
interface GigabitEthernet0/33
switchport access vlan 18
switchport mode access
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
queue-set 2
mls qos trust cos
no snmp trap link-status
auto qos voip trust
spanning-tree portfast
08-28-2012 01:44 PM
Hi,
the correct syntax was sh spanning-tree interface g0/33 portfast.
Sorry for the error.
Regards.
Alain
Don't forget to rate helpful posts.
08-28-2012 01:51 PM
Hi,
it's enabled
#sh spanning-tree interface gigabitEthernet 0/33 portfast
VLAN0060 enabled
08-29-2012 12:06 AM
Hi tdrumond,
are you running Rapid PVST ??
which swiitch ??
may be its a bug :
I has been detected on Cat3550 as CSCeb48939 .
Regards
Please rate if it helps.
08-29-2012 05:10 AM
Hi sandeepchoudhary21
I'm using a 3560:
Cisco IOS Software, C3560 Software (C3560-IPBASE-M), Version 12.2(35)SE5, RELEASE SOFTWARE (fc1)
and
spanning-tree mode pvst
08-29-2012 05:14 AM
Hi there,
disable the DTP with switchport none and let me know pls. Hardcode the speed and the duplex mode too.
Take Care
Alessio
08-30-2012 06:10 AM
Ok, now it's off, but I need some time to get results
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