Go CCIE Go!! - A Cisco Certified Internetwork Expert

It would appear that you have no link participating in spanning tree between Cat3 and other switches.
How does “show interface trunk” look?
Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, JNCIE-M #153, JNCIS-ER, CISSP, et al. CCSI/JNCI-M/JNCI-ER VP - Technical Training - IPexpert, Inc. IPexpert Sr. Technical Instructor
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—–Original Message—– From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Jeffrey Biggs Sent: Monday, December 31, 2007 12:27 PM To: ‘Cisco certification’ Subject: IPEXPERT LAB 26: STANDBY Interface on CAT3560
I have setup the required “standby interface” on the 3560 but for some reason, the 3560 is not seeing the 3550 (switch 2) as the root. But it is learning all the vlans via VTP and is forwarding traffic, which really baffles me. I am running MST on the switches with switch 2 as the root and switch 1 as the VTP server:

(switch 1)=====po12======(switch 2)———–Fa0/19 (fa0/20 in standby)——(switch 3)

All switches running MST and switch 1 sees switch 2 as root, but 3 don’t:

Cat-2>sh span

MST0
Spanning tree enabled protocol mstp
Root ID Priority 24576
Address 000e.d799.3f00
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 24576 (priority 24576 sys-id-ext 0)
Address 000e.d799.3f00
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Interface Role Sts Cost Prio.Nbr Type
—————- —- — ——— ——– ——————————–
Fa0/1 Desg FWD 200000 128.1 P2p
Fa0/6 Desg FWD 200000 128.6 P2p
Fa0/7 Desg FWD 2000000 128.7 P2p
Fa0/8 Desg FWD 2000000 128.8 P2p
Fa0/9 Desg FWD 200000 128.9 P2p
Fa0/12 Desg FWD 2000000 128.12 P2p
Fa0/13 Desg FWD 2000000 128.13 P2p
Fa0/19 Desg FWD 200000 128.19 P2p
Fa0/20 Desg FWD 200000 128.20 P2p

Interface Role Sts Cost Prio.Nbr Type
—————- —- — ——— ——– ——————————–

Po12 Desg FWD 20000 128.65 P2p

Cat-2>

Cat-3#sh spanning-tree

MST0
Spanning tree enabled protocol mstp
Root ID Priority 32768
Address 0011.bb1c.f000
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32768 (priority 32768 sys-id-ext 0)
Address 0011.bb1c.f000
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Interface Role Sts Cost Prio.Nbr Type
—————- —- — ——— ——– ——————————–
Fa0/5 Desg FWD 200000 128.7 P2p

Cat-3#