i HAVE AS MAIN SWITCH N 3048(root switch) AND POWERCONNECT 3548 in stack
of 5 switches and powerconnect 5448 as vm switch,
at the moment spaning tree is constantly changing , without plugin new devices,
what could cause the problem?
If this possible that n3548 and 5448 using by deafaut short path cost but n3048 it looks like that path
n long
belong is spanig tree config from all three switches
switch n3048
=~=~=~=~=~=~=~=~=~=~=~= PuTTY log 2015.07.31 14:31:29 =~=~=~=~=~=~=~=~=~=~=~=
show spanning-tree
Spanning Tree: Enabled - BPDU Flooding: Disabled - Portfast BPDU Filtering: Enabled
Mode: rstp
CST Regional Root: 00:00:F8:B1:56:72:31:BA
Regional Root Path Cost: 0
ROOT ID
Priority 0
Address F8B1.5672.31BA
This Switch is the Root.
Hello Time: 2s Max Age: 20s Forward Delay: 15s Transmit Hold Count: 6s
Bridge Max Hops: 20
Interfaces
Name State Prio.Nbr Cost Sts Role Restricted
--------- -------- --------- --------- ---- ----- ----------
Gi1/0/1 Enabled 128.1 0 DIS Disb No
Gi1/0/2 Enabled 128.2 0 DIS Disb No
Gi1/0/3 Enabled 128.3 200000 FWD Desg No
Gi1/0/4 Enabled 128.4 200000 FWD Desg No
stack switch
=~=~=~=~=~=~=~=~=~=~=~= PuTTY log 2015.07.31 14:32:41 =~=~=~=~=~=~=~=~=~=~=~=
Spanning tree enabled mode RSTP
Default port cost method: short
Root ID Priority 0
Address f8:b1:56:72:31:ba
Cost 4
Port ch1
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32768
Address a4:ba:db:65:1b:44
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Number of topology changes 4587 last change occurred 00:08:25 ago
Times: hold 1, topology change 35, notification 2
hello 2, max age 20, forward delay 15
Interfaces
Name State Prio.Nbr Cost Sts Role PortFast Type
[0mMore: <space>, Quit: q, One line: <return>
------ -------- -------- --------- ------ ---- -------- -----------------
1/e1 enabled 128.1 19 Frw Desg Yes P2P (RSTP)
1/e2 enabled 128.2 19 Frw Desg Yes P2P (RSTP)
1/e3 enabled 128.3 19 Frw Desg Yes P2P (RSTP)
1/e4 enabled 128.4 19 Frw Desg Yes P2P (RSTP)
1/e5 enabled 128.5 19 Frw Desg Yes P2P (RSTP)
1/e6 enabled 128.6 19 Frw Desg Yes P2P (RSTP)
1/e7 enabled 128.7 19 Frw Desg Yes P2P (RSTP)
vm switch#
sp
[Kconsole# sh spanning-tree
Spanning tree enabled mode RSTP
Default port cost method: short
Root ID Priority 0
Address f8:b1:56:72:31:ba
Cost 4
Port g41
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32768
Address 5c:26:0a:9b:27:73
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Number of topology changes 8149 last change occurred 667:56:01 ago
Times: hold 1, topology change 35, notification 2
hello 2, max age 20, forward delay 15
Interfaces
Name State Prio.Nbr Cost Sts Role PortFast Type
[0mMore: <space>, Quit: q, One line: <return>
------ -------- -------- --------- ------ ---- -------- -----------------
g1 enabled 128.1 100 Frw Desg Yes P2P (RSTP)
g2 enabled 128.2 100 Frw Desg Yes P2P (RSTP)
g3 enabled 128.3 100 Frw Desg Yes P2P (RSTP)
g4 enabled 128.4 100 Frw Desg Yes P2P (RSTP)
g5 enabled 128.5 100 Frw Desg Yes P2P (RSTP)
g6 enabled 128.6 100 Frw Desg Yes P2P (RSTP)
g7 enabled 128.7 100 Dsbl Dsbl No -
g8 enabled 128.8 100 Dsbl Dsbl No -
g9 enabled 128.9 100 Dsbl Dsbl No -
g10 enabled 128.10 100 Dsbl Dsbl No -
g11 enabled 128.11 100 Dsbl Dsbl No -
g12 enabled 128.12 100 Dsbl Dsbl No -
g13 enabled 128.13 100 Dsbl Dsbl No -
g14 enabled 128.14 100 Dsbl Dsbl No -
g15 enabled 128.15 100 Dsbl Dsbl No -
g16 enabled 128.16 100 Dsbl Dsbl No -
