Solved

Vlan Trunking Configurations

Posted on 2011-09-22
4
289 Views
Last Modified: 2012-05-12
It is my understanding that a switch port can be either access or trunk port and not both at the same time.  When you configure a port as "switchport mode trunk", the configuration on the same port of "swithport ccess vlan xx" will be ignored because it has no consequence or noeffect

Looking at the configuration below, I notice the port in question is in trunk mode even though the command did not explicitly set the port to trunk

sh run int g0/2
Building configuration...

Current configuration : 109 bytes
!
interface GigabitEthernet0/2
 switchport access vlan 5
 switchport trunk native vlan 5
 no ip address
!

sh int status
Gi0/2  connected    trunk      a-full a-1000 10/100/1000BaseTX

My question is; does the command " switchport trunk native vlan" turn trunking to on just as the command "switchport mode trun"?

Thanks
0
Comment
Question by:donemore2003
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
4 Comments
 
LVL 26

Accepted Solution

by:
Soulja earned 500 total points
ID: 36582489
No. When you don't use either of the mode commands the port is essentially dynamic. It the port above connects to another trunk port, it will negotiate into a trunk and have vlan 5 as its native. Otherwise, it is an access port in vlan 5. This is why is it best to put ports in a certain mode to insure they remain that way.
0
 
LVL 26

Expert Comment

by:Soulja
ID: 36582500
You can confirm what I am saying by entering:

sh interface gig0/2 switchport
0
 
LVL 26

Expert Comment

by:Soulja
ID: 36582620
Just to add:

switchport mode trunk or switchport mode access sets to port to a static access or trunk port. In the case of switchport mode trunk, it is still possible for it to try to negotiate with other dynamic ports so you add the command switchport trunk nonnegotiate to keep it from sent DTP packets.
0
 

Author Comment

by:donemore2003
ID: 36582810
Thank you Soulja.  Thanks for pointing out that by not specifying the mode, the port can either be access or trunk depending on what is connecting to that port.
0

Featured Post

Resolve Critical IT Incidents Fast

If your data, services or processes become compromised, your organization can suffer damage in just minutes and how fast you communicate during a major IT incident is everything. Learn how to immediately identify incidents & best practices to resolve them quickly and effectively.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

I see many questions here on Experts Exchange regarding switch port configurations and trunks. This article is meant for beginners in the subject to help to get basic knowledge about Virtual Local Area Network (VLAN (http://en.wikipedia.org/wiki/Vir…
Arrow Electronics was searching for a KVM  (Keyboard/Video/Mouse) switch that could display on one single monitor the current status of all units being tested on the rack.
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…

737 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question