Ways to identify a trunk port?

Hi All,

Besides 'show running-config', what other ways are they to identify a trunk port?

The running-config will allow you to see something like this:

!
Interface FastEthernet 0/23
switchport mode trunk
!

Is this the only way?

Thanks,
T800

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Comments

Netstudent

you could try show int trunk or show int fa0/1 trunk. ALso show int fa0/1 switchport should give you some trunking info. T

mikej412

show interface trunk

S3750-1#show interface trunk

Port        Mode         Encapsulation  Status        Native vlan
Fa1/0/13    desirable    n-isl          trunking      1
Fa1/0/14    desirable    n-isl          trunking      1
Fa1/0/15    desirable    n-isl          trunking      1

Port        Vlans allowed on trunk
Fa1/0/13    1-4094
Fa1/0/14    1-4094
Fa1/0/15    1-4094

Port        Vlans allowed and active in management domain
Fa1/0/13    1,104-105,199,999
Fa1/0/14    1,104-105,199,999
Fa1/0/15    1,104-105,199,999

Port        Vlans in spanning tree forwarding state and not pruned
Fa1/0/13    1,104
Fa1/0/14    1
Fa1/0/15    1

S3750-1#show interface Fa1/0/13 trunk 

Port        Mode         Encapsulation  Status        Native vlan
Fa1/0/13    desirable    n-isl          trunking      1

Port        Vlans allowed on trunk
Fa1/0/13    1-4094

Port        Vlans allowed and active in management domain
Fa1/0/13    1,104-105,199,999

Port        Vlans in spanning tree forwarding state and not pruned
Fa1/0/13    1,104
S3750-1#

S3750-1#show interface Fa1/0/13 switchport
Name: Fa1/0/13
Switchport: Enabled
Administrative Mode: dynamic desirable
Operational Mode: trunk
Administrative Trunking Encapsulation: negotiate
Operational Trunking Encapsulation: isl
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 1 (default)
Administrative Native VLAN tagging: enabled
Voice VLAN: none
Administrative private-vlan host-association: none 
Administrative private-vlan mapping: none 
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk private VLANs: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
          
Protected: false
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none
S3750-1#

t800

Thank you!

T800

mwgood

sh int status | in trunk

mikej412

mwgood wrote:

sh int status | in trunk

Good one

S3750-1#show interfaces status | include trunk
Fa1/0/13                     connected    trunk      a-full  a-100 10/100BaseTX
Fa1/0/14                     connected    trunk      a-full  a-100 10/100BaseTX
Fa1/0/15                     connected    trunk      a-full  a-100 10/100BaseTX

I'm sure there are even a few people working on CCNP exams will smack their forehead with the palm of their hand wondering why they didn't figure this one out sooner

I'll post a sample with the CLI help for the output modifier and the show int status with and without the modifier.

S3750-1#show interfaces status ?
  err-disabled  Show interface error disabled state
  inactive      Show interface inactive state
  module        Limit display to interfaces on module
  |             Output modifiers
  <cr>

S3750-1#show interfaces status | ?
  append    Append redirected output to URL (URLs supporting append operation
            only)
  begin     Begin with the line that matches
  exclude   Exclude lines that match
  include   Include lines that match
  redirect  Redirect output to URL
  tee       Copy output to URL

S3750-1#show interfaces status | include trunk
Fa1/0/13                     connected    trunk      a-full  a-100 10/100BaseTX
Fa1/0/14                     connected    trunk      a-full  a-100 10/100BaseTX
Fa1/0/15                     connected    trunk      a-full  a-100 10/100BaseTX
S3750-1#show interface status

Port      Name               Status       Vlan       Duplex  Speed Type
Fa1/0/1                      notconnect   104          auto   auto 10/100BaseTX
Fa1/0/2                      notconnect   104          auto   auto 10/100BaseTX
Fa1/0/3                      notconnect   104          auto   auto 10/100BaseTX
Fa1/0/4                      notconnect   104          auto   auto 10/100BaseTX
Fa1/0/5                      notconnect   104          auto   auto 10/100BaseTX
Fa1/0/6                      notconnect   104          auto   auto 10/100BaseTX
Fa1/0/7                      notconnect   104          auto   auto 10/100BaseTX
Fa1/0/8                      notconnect   104          auto   auto 10/100BaseTX
Fa1/0/9                      notconnect   104          auto   auto 10/100BaseTX
Fa1/0/10                     notconnect   104          auto   auto 10/100BaseTX
Fa1/0/11                     notconnect   104          auto   auto 10/100BaseTX
Fa1/0/12                     notconnect   104          auto   auto 10/100BaseTX
Fa1/0/13                     connected    trunk      a-full  a-100 10/100BaseTX
Fa1/0/14                     connected    trunk      a-full  a-100 10/100BaseTX
Fa1/0/15                     connected    trunk      a-full  a-100 10/100BaseTX
Fa1/0/16                     connected    1          a-full  a-100 10/100BaseTX
Fa1/0/17                     notconnect   1            auto   auto 10/100BaseTX
Fa1/0/18                     notconnect   1            auto   auto 10/100BaseTX
Fa1/0/19                     notconnect   1            auto   auto 10/100BaseTX
Fa1/0/20                     notconnect   1            auto   auto 10/100BaseTX
Fa1/0/21                     notconnect   1            auto   auto 10/100BaseTX
Fa1/0/22                     connected    1          a-full  a-100 10/100BaseTX
Fa1/0/23                     connected    1          a-full  a-100 10/100BaseTX
Fa1/0/24                     notconnect   1            auto   auto 10/100BaseTX
Gi1/0/1                      notconnect   1            auto   auto Not Present
Gi1/0/2                      notconnect   1            auto   auto Not Present
S3750-1#

t800

mwgood wrote:

sh int status | in trunk

Never seen that command before. Very clever!

T800

bohra_ajay

Thankx for the command thats really very smart.

dtlokee

mwgood wrote:

sh int status | in trunk

Good command to know but it won't work on the sims in the CCNA exam, none of the pipes (|) commands work.

bighornsheep

Slightly off topic....but could you have more than one trunk between 2 switch? Or are your trunks configured to different switches?

networker050184

You can make as many trunks as you want but spanning tree will block the redundant paths. You can build an etherchannel to effectivley use all the bandwidth of the redundant links.

mgmguy1

Bump. I was making some notes on different show commands when I came upon this thread. It might be good to look at and make some notes for yourself.

webspider

Hi
The "show interfaces status" command will display the status of all the ports in a switch