Solved

vlan trunking

Posted on 2013-12-20
3
579 Views
Last Modified: 2013-12-20
Hello,
I understand vlans and trunking. What I don't understand is the "access mode vlan" and "trunking native mode vlan" on a trunking port and why the difference and what it means.

I know that all traffic for a certain vlan is only for switchports designated for that vlan. But what is the native vlan and what traffic does it carry?

What does this mean below also:

Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 10 (VLAN0010)

Thanks.
0
Comment
Question by:tolinrome
[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
  • 2
3 Comments
 
LVL 57

Assisted Solution

by:giltjr
giltjr earned 250 total points
ID: 39732263
--> Negotiation of Trunking: On

Means that this port is not forced as a trunk.  It will negotiate with the device connected to that port to see if it should run as in trunk or access mode.

--> Access Mode VLAN: 1 (default)

Use VLAN 1 if this port is running in access mode.  So if negotiation as a trunk fails, this port will be in access mode.

--> Trunking Native Mode VLAN: 10 (VLAN0010)

If this port is running in trunk mode, the native VLAN is VLAN 10.
0
 
LVL 11

Accepted Solution

by:
Miftaul earned 250 total points
ID: 39732288
But what is the native vlan and what traffic does it carry?

Native VLAN carries control traffic, say the keepalives like dtp, cdp to keep the trunks on.

Negotiation of Trunking: On
It means one end of the link is negotiating dtp packets with the other end to form trunk. if the other end is set to auto or trunk, the trunk forms. For security purposes, we usually disable this feature by using "switchport nonegotiate"

Access Mode VLAN: 1 (default)
If the trunk is not forming, this link will default to access port VLAN1

Trunking Native Mode VLAN: 10 (VLAN0010)
Native VLAN carries control traffic, here the Native VLAN is set to VLAN10
0
 
LVL 57

Expert Comment

by:giltjr
ID: 39732521
On a trunk you can have tagged or untagged frames.  Any frame that is untagged is assumed to be on the native VLAN.  So if your native VLAN is VLAN 10, any untagged traffic is assumed to be on VLAN 10.

Some switches have started allowing you to tag the native VLAN traffic.  This is so somebody cant craft frames that are  802.1Q double-tagged which could/would allow them to travers VLAN's.  One reference:

http://www.networkworld.com/community/node/38732
0

Featured Post

Connect further...control easier

With the ATEN CE624, you can now enjoy a high-quality visual experience powered by HDBaseT technology and the convenience of a single Cat6 cable to transmit uncompressed video with zero latency and multi-streaming for dual-view applications where remote access is required.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
replacing 2811 to ISR 4331 2 49
connect to cisco 2690 series 6 24
Change to New Domain, carry Wks configs foward? 4 29
NFS v4 7 24
When it comes to security, there are always trade-offs between security and convenience/ease of administration. This article examines some of the main pros and cons of using key authentication vs password authentication for hosting an SFTP server.
In this article, I am going to show you how to simulate a multi-site Lab environment on a single Hyper-V host. I use this method successfully in my own lab to simulate three fully routed global AD Sites on a Windows 10 Hyper-V host.
Internet Business Fax to Email Made Easy - With  eFax Corporate (http://www.enterprise.efax.com), you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, f…
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…

730 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