04-17-2007 05:07 AM - edited 03-05-2019 03:30 PM
Hi Guys,
We have a 2950 running in rapid pvst mode. There are some 3 com switches connected to the first couple of ports, some running rstp and some stp. The ports are not trunk, they are access ports for vlan 4 on that floor without portfast:
show spanning-tree vlan 4
VLAN0004
Spanning tree enabled protocol rstp
Root ID Priority 4100
Address 0011.bbee.b580
Cost 4
Port 25 (GigabitEthernet0/1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32772 (priority 32768 sys-id-ext 4)
Address 0012.0153.c640
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Fa0/1 Desg FWD 19 128.1 P2p
Fa0/2 Desg FWD 19 128.2 P2p Peer(STP)
Fa0/3 Desg FWD 19 128.3 P2p Peer(STP)
Fa0/5 Desg FWD 19 128.5 P2p Peer(STP)
Fa0/6 Desg FWD 19 128.6 P2p
All the other ports on the 2950 is configured with portfast. However, when one of the ports configured with portfast goes to forwarding, connection to all workstations on the STP (not rstp) 3com switches are lost while STP converges and the following is seen:
.Apr 17 12:53:44: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/9, changed state to down
.Apr 17 12:53:45: %LINK-3-UPDOWN: Interface FastEthernet0/9, changed state to down
.Apr 17 12:53:49: RSTP(4): syncing port Fa0/1
.Apr 17 12:53:49: RSTP(4): syncing port Fa0/2
.Apr 17 12:53:49: RSTP(4): syncing port Fa0/3
.Apr 17 12:53:49: RSTP(4): syncing port Fa0/5
.Apr 17 12:53:49: RSTP(4): syncing port Fa0/6
.Apr 17 12:53:49: RSTP(4): initializing port Fa0/9
.Apr 17 12:53:51: %LINK-3-UPDOWN: Interface FastEthernet0/9, changed state to up
.Apr 17 12:53:52: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/9, changed state to up
.Apr 17 12:54:04: RSTP(4): Fa0/2 fdwhile Expired
.Apr 17 12:54:04: RSTP(4): Fa0/3 fdwhile Expired
.Apr 17 12:54:04: RSTP(4): Fa0/5 fdwhile Expired
.Apr 17 12:54:19: RSTP(4): Fa0/2 fdwhile Expired
.Apr 17 12:54:19: RSTP(4): Fa0/3 fdwhile Expired
.Apr 17 12:54:19: RSTP(4): Fa0/5 fdwhile Expired
My understanding was that portfast ports would not cause notifications, or is there something I am missing?
Thanks!
Jacques
04-23-2007 06:18 AM
Ports with the STP portfast feature enabled will not cause TCs when going to or from the forwarding state.
http://www.cisco.com/warp/public/473/170.html#topology_change
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