05-09-2008 07:09 AM - edited 03-05-2019 10:52 PM
Hi ,
when i do
sh spanning-tree
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 32769
Address 000b.be50.ed40
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 000b.be50.ed40
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300
Interface Port ID Designated Port ID
Name Prio.Nbr Cost Sts Cost Bridge ID Prio.Nbr
---------------- -------- --------- --- --------- -------------------- --------
Fa0/1 128.1 19 FWD 0 32769 000b.be50.ed40 128.1
Fa0/2 128.2 100 FWD 0 32769 000b.be50.ed40 128.2
Fa0/3 128.3 19 FWD 0 32769 000b.be50.ed40 128.3
Fa0/4 128.4 19 FWD 0 32769 000b.be50.ed40 128.4
Fa0/5 128.5 19 FWD 0 32769 000b.be50.ed40 128.5
Fa0/6 128.6 19 FWD 0 32769 000b.be50.ed40 128.6
Fa0/8 128.8 19 FWD 0 32769 000b.be50.ed40 128.8
Fa0/10 128.10 19 FWD 0 32769 000b.be50.ed40 128.10
Fa0/11 128.11 19 FWD 0 32769 000b.be50.ed40 128.11
Fa0/13 128.13 19 FWD 0 32769 000b.be50.ed40 128.13
Fa0/15 128.15 19 FWD 0 32769 000b.be50.ed40 128.15
My question is how we cfan find root port?i try this command
sh mac-address-table address 000b.be50.ed40
Mac Address Table
------------------------------------------
Vlan Mac Address Type Ports
---- ----------- ---- -----
no luck
05-09-2008 07:29 AM
show spanning-tree bridge address will show the MAC address of the bridge you are on.
If you are looking for the root port on a switch show spanning-tree root port.
Hope that helps.
05-09-2008 07:52 AM
thanks for reply
when i do command
show spanning-tree bridge address
show spanning-tree root port
VLAN0001 This bridge is root
this comes
show spanning-tree bridge address
VLAN0001 000b.be50.ed40
05-09-2008 08:09 AM
The bridge you are on is the root bridge (as Jon stated). It's using the system MAC, so you will not see it in the ARP table. Another way (probably not 100% effective) to find the system MAC is take the MAC of fa0/1 and subtract 1. In your case the MAC address of your fa0/1 interface should be 000b.be50.ed41. Is that correct? The safer method is the show spanning-tree bridge address.
05-09-2008 07:41 AM
Hi Mahesh,
This bridge will not have a root port because it is the root bridge itself.
See "This bridge is the root" statement under
Root ID Priority 32769
Address 000b.be50.ed40
For non-root bridges it would show up among the ports in FWD or BLK state.
Cheers:
Istvan
05-09-2008 10:19 AM
thanks for reply
how can i find root bridge and root port in the network
05-09-2008 10:35 AM
Hi Mahesh,
The "show spanning-tree root" command will show you the root bridge IDs for all vlans that the local switch participates in.
The easiest way to find a root port on a switch is the "show spanning-tree vlan x" command for a given vlan.
Applying this command repetitively and following the root ports up through several non-root switches will lead you to the root switch.
Cheers:
Istvan
05-09-2008 07:42 AM
Mahesh
Just to add to Collin's post. This switch will not have a root port for vlan 1 because it is the root bridge ie.
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 32769
Address 000b.be50.ed40
This bridge is the root <----------
Root bridges should only have designated ports in the vlans they are root for.
Jon
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