Switch command questions

xanderuk2

Good morning all (From Scotland time at least)

I have a couple of questions on some grey areas I have come across during studying this week so far. All Switch related…

First, in order to determine what ports on a switch (2900 series onwards) are configured as trunk ports, the following command will work:

Switch#show interfaces trunk
Or
Switch#show interfaces switchport

Also, when locating the root-bridge in a switch network, will the following command suffice:

Switch#show spanning-tree
Or do we have to specify a VLAN, such as VLAN1 to determine the root bridge? -
Switch#show spanning-tree VLAN1

As fas as I am aware, CCNA does not cover the whole "Spanning-tree instance per VLAN" which leads me to believe the 1st command will tell me what switch is the root bridge
I have been unable to find an answer to the above, and can't access the switches at work until Friday (after I have my exam)

aray

Switch#sh int ?
....
trunk Show interface trunk information
switchport Show interface switchport information

(looks like that should do it)

And

Switch#sh int switchport
Name: Fa0/1
Switchport: Enabled
Administrative Mode: dynamic desirable
Operational Mode: static access
Administrative Trunking Encapsulation: dot1q
Operational Trunking Encapsulation: native
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 1 (default)
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001

and

(I have no trunks)

Switch#sh int trunk

Switch#

Not sure on the rest, but I hope this helps:

Switch#sh spanning-tree

VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 32769
Address 000a.4143.9400
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 000a.4143.9400
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

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Fa0/1 128.1 100 FWD 0 32769 000a.4143.9400 128.1
Fa0/3 128.3 19 FWD 0 32769 000a.4143.9400 128.3
Fa0/4 128.4 19 FWD 0 32769 000a.4143.9400 128.4
Fa0/5 128.5 19 FWD 0 32769 000a.4143.9400 128.5
Fa0/6 128.6 19 FWD 0 32769 000a.4143.9400 128.6
Fa0/7 128.7 19 FWD 0 32769 000a.4143.9400 128.7
Fa0/8 128.8 19 FWD 0 32769 000a.4143.9400 128.8

Interface Port ID Designated Port ID
Name Prio.Nbr Cost Sts Cost Bridge ID Prio.Nbr

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Fa0/10 128.10 19 FWD 0 32769 000a.4143.9400 128.10
Fa0/11 128.11 19 FWD 0 32769 000a.4143.9400 128.11
Fa0/12 128.12 19 FWD 0 32769 000a.4143.9400 128.12
Fa0/13 128.13 19 FWD 0 32769 000a.4143.9400 128.13
Fa0/14 128.14 19 FWD 0 32769 000a.4143.9400 128.14
Fa0/15 128.15 19 FWD 0 32769 000a.4143.9400 128.15
Fa0/16 128.16 100 FWD 0 32769 000a.4143.9400 128.16
Fa0/17 128.17 19 FWD 0 32769 000a.4143.9400 128.17
Fa0/18 128.18 100 FWD 0 32769 000a.4143.9400 128.18
Fa0/19 128.19 19 FWD 0 32769 000a.4143.9400 128.19

Switch#sh spanning-tree ?
active Report on active interfaces only
backbonefast Show spanning tree backbonefast status
blockedports Show blocked ports
bridge Status and configuration of this bridge
detail Detailed information
inconsistentports Show inconsistent ports
interface Spanning Tree interface status and configuration
pathcost Show Spanning pathcost options
root Status and configuration of the root bridge
summary Summary of port states
uplinkfast Show spanning tree uplinkfast status
vlan VLAN Switch Spanning Trees
| Output modifiers
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