Trunking and Autonegotiation

[bevans]

I have a 6500 switch (core) and a 3500 switch (remote site) that connect via and ISP fiber link up. I have had issues with the autonegotiation on the GBICs in my Cisco gear as to connecting up with the ISP equipment. I issued the following commands...

6500: set port negotiation 3/5 disable

3500: speed nonegotiate (set on gig0/1)

However, I am still having issues. I can also remove autonegotiation on the trunking by doing this...

6500:

set trunk 3/5 nonegotiate dot1q 1-1005,1025-4094

--instead of--

set trunk 3/5 on dot1q 1-1005,1025-4094

3500:

switchport nonegotiate (not set now)

(to be set on int gig0/1)

So, my question is:

1. What is the difference from the trunking mode to be ON or NONEGOTIATE on the 6500?

2. What is the difference from the SWITCHPORT NONEGOTIATE command being on or off on the 3500?

Please help! Thanks in advance.

- BE

[sachinraja · Accepted solution]

Hello BE,

DTP is a dynamic protocol , which sets up trunk.. I have attached a fantastic URL for DTP configurations.. It gives answers to all the questions asked by you... really cool document... have a look at it:

http://cisco.com/en/US/products/hw/switches/ps700/products_tech_note09186a008012ecf3.shtml#dtp

Let us know if you have any more queries.. all the best.. rate replies if found useful.

Raj

[bevans]

Raj,

Thank you for your post. That article is very informative as you mentioned. It confirms for me what I thought I knew clearly. Thanks again!

- BE