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How to configure RSTP between Mikrotik and CISCO

Mon Feb 07, 2011 11:32 am

how should i configure Mikrotik RSTP to communicate with Cisco RSTP/MSTP protocol ???
I've tried everything from cisco/mikrotik manuals.
but cisco cisco still can't see mikrotik Bridge, and receiving it's BPDU's. But i can see that cisco (3550) sending it's BPDUs but seems to be mikrotik isn't receiving them.
BPDU-Guard and BPDU-filter are disabled on cisco.
cisco has highest bridge switch id priority with 4096 increment steps as suggested by cisco - 61440 .
placed lowest priority on mikrotik bridge 4096 (1000 in hex) as suggested by cisco

still nothing
switches/bridges can't see and communicate to each other. not building spaneeng-tree topology and not electing proper root bridge (own local root bridge for each device as they can't see any other device)

Please, any suggestions would be helpful (

/interface bridge> print from=16
Flags: X - disabled, R - running 
 0  R name="bridge.VLAN1" mtu=1500 l2mtu=1520 arp=enabled 
      mac-address=00:0C:42:55:46:14 protocol-mode=rstp priority=0x1000 
      auto-mac=yes admin-mac=00:00:00:00:00:00 max-message-age=20s 
      forward-delay=15s transmit-hold-count=6 ageing-time=5m

/interface bridge> monitor bridge.VLAN1 
                  state: enabled
    current-mac-address: 00:0C:42:55:46:14
            root-bridge: yes
         root-bridge-id: 0x1000.00:0C:42:55:46:14
         root-path-cost: 0
              root-port: none
             port-count: 3
  designated-port-count: 2
sh span det
 MST0 is executing the mstp compatible Spanning Tree protocol
  Bridge Identifier has priority 61440, sysid 0, address 000b.bea2.7e80
  Configured hello time 2, max age 20, forward delay 15, transmit hold-count 6
  We are the root of the spanning tree
  Topology change flag not set, detected flag not set
  Number of topology changes 4 last change occurred 2d22h ago
          from FastEthernet0/9
  Times:  hold 1, topology change 35, notification 2
          hello 2, max age 20, forward delay 15
  Timers: hello 0, topology change 0, notification 0

 Port 1 (FastEthernet0/1) of MST0 is designated forwarding
   Port path cost 200000, Port priority 128, Port Identifier 128.1.
   Designated root has priority 61440, address 000b.bea2.7e80
   Designated bridge has priority 61440, address 000b.bea2.7e80
   Designated port id is 128.1, designated path cost 0
   Timers: message age 0, forward delay 0, hold 0
   Number of transitions to forwarding state: 1
   Link type is point-to-point by default, Internal
   BPDU: sent 127367, received 0

sh span sum
Switch is in mst mode (IEEE Standard)
Root bridge for: MST0
Extended system ID           is enabled
Portfast Default             is disabled
PortFast BPDU Guard Default  is disabled
Portfast BPDU Filter Default is disabled
Loopguard Default            is disabled
EtherChannel misconfig guard is disabled
UplinkFast                   is disabled
BackboneFast                 is disabled
Configured Pathcost method used is short (Operational value is long)

Name                   Blocking Listening Learning Forwarding STP Active
---------------------- -------- --------- -------- ---------- ----------
MST0                         0         0        0          1          1
---------------------- -------- --------- -------- ---------- ----------
1 mst                        0         0        0          1          1

sh span mst 0 det
##### MST0    vlans mapped:   1-4094
Bridge        address 000b.bea2.7e80  priority      61440 (61440 sysid 0)
Root          this switch for the CIST
Operational   hello time 2 , forward delay 15, max age 20, txholdcount 6
Configured    hello time 2 , forward delay 15, max age 20, max hops    20

FastEthernet0/1 of MST0 is designated forwarding
Port info             port id          128.1  priority    128  cost      200000
Designated root       address 000b.bea2.7e80  priority  61440  cost           0
Design. regional root address 000b.bea2.7e80  priority  61440  cost           0
Designated bridge     address 000b.bea2.7e80  priority  61440  port id    128.1
Timers: message expires in 0 sec, forward delay 0, forward transitions 1
Bpdus sent 127394, received 0
MikroTik Support
MikroTik Support
Posts: 592
Joined: Tue Dec 02, 2008 10:55 am

Re: How to configure RSTP between Mikrotik and CISCO

Mon Feb 07, 2011 2:12 pm

Unfortunately current RouterOS RSTP implementation is not compatible with MSTP.

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