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Cisco 3560 configured trunk port staying in VLAN 1

jdavid6568
Level 1
Level 1

I am configuring a 3560 switch and configuring the port in trunking mode but when I do show interface status it keeps showing up in VLAN 1. I also tried to verify via the show in trunk command and it is not showing the port being trunked. Below is the port configuration and the output of each show command. Interfaces Gi0/19 and Gi0/20 are the ones in question. Any ideas on how to fix this?

interface GigabitEthernet0/19

description phlphoef2 gi0/1

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 30

switchport mode trunk

speed 100

duplex full

!

interface GigabitEthernet0/20

description phlphoef2 gi0/2

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 50,60

switchport mode trunk

speed 100

duplex full

phlphoes9#show int status

Port      Name               Status       Vlan       Duplex  Speed Type
Gi0/19    phlphoef2 gi0/1    notconnect   1            full    100 10/100/1000BaseTX
Gi0/20    phlphoef2 gi0/2    notconnect   1            full    100 10/100/1000BaseTX

phlphoes9#show int trunk

Port        Mode         Encapsulation  Status        Native vlan
Gi0/10      on           802.1q         trunking      1
Gi0/11      on           802.1q         trunking      1
Gi0/12      on           802.1q         trunking      1
Gi0/13      on           802.1q         trunking      1
Gi0/14      on           802.1q         trunking      1
Gi0/15      on           802.1q         trunking      1
Gi0/16      on           802.1q         trunking      1
Gi0/17      on           802.1q         trunking      1
Gi0/23      on           802.1q         trunking      1

2 Accepted Solutions

Accepted Solutions

IAN WHITMORE
Level 4
Level 4

This is normal. One because it's not trunking (i.e. the interface isn't up), no vlan is being negotiated.

Also, VLAN 1 is the native VLAN and is also enabled by default. You can change this though if you wish, but you must change it on both ends of the trunk.

HTH,

Ian

View solution in original post

Edwin Summers
Level 3
Level 3

Looks like Ian pretty much covered it, so I just wanted to ask if you had connected the interfaces to another device yet as they are showing "not connected".  Ensure the interfaces on the far side (if connected) are not shutdown.

View solution in original post

5 Replies 5

IAN WHITMORE
Level 4
Level 4

This is normal. One because it's not trunking (i.e. the interface isn't up), no vlan is being negotiated.

Also, VLAN 1 is the native VLAN and is also enabled by default. You can change this though if you wish, but you must change it on both ends of the trunk.

HTH,

Ian

Edwin Summers
Level 3
Level 3

Looks like Ian pretty much covered it, so I just wanted to ask if you had connected the interfaces to another device yet as they are showing "not connected".  Ensure the interfaces on the far side (if connected) are not shutdown.

Thank you both. This is just prep work for a new firewall migration. So the interfaces are not connected to anything until Saturday. I was under the impression that once you configured the trunk and allowed the vlans that it was a static configuration. But what both of you answered makes perfect sense. Thanks again for the clarification.

No worries. Can you mark the post as solved.

thanks,

Ian

I was facing the same situation on Cisco Catalyst 3850, but I came to know this is normal behavior, when you configured a port as a "Trunk Port"and it is down then it will reflect under a native Vlan ports and as soon you turn it on it will be removed from Vlan ports.

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