10GB interface and route switch trunk

[WILLIAM STEGMAN]

I found a post from 2007 that answered this in the negative, but wanted to check if there is more recent info regarding the ability of a 10GB interface in a 4510 to negotiate down to 1GB. I found that under the int config the speed command only allows the option nonegotiate, which leads me to believe it has the ability to negotiate, but I can't test. This question is arising as part of a need to migrate off our current switching infrastructure in 2 phases. Our network closet has some fiber uplinks to our current data center switch, and while I will be replacing the distribution layer with 10GB trunk links, I'm looking to see if I can keep the access layer in tact until phase 2, which is replacing the access layer switches and installing a couple distribution switches with 10GB links.

I also wanted to ask what the trunk link showing up as port 15/1 and 16/1 was. Show port indicates it's virtual and associated with the route switch. I'm trying to account for all the trunk links between the data center and the access layer switches, and these trunks popped up.

HBG_SW02 (enable) sh port 15/1

* = Configured MAC Address

# = 802.1X Authenticated Port Name.

Port Name Status Vlan Duplex Speed Type

----- -------------------- ---------- ---------- ------ ----------- ------------

15/1 connected trunk full 1000 Route Switch

15/1 nonegotiate isl trunking 1

16/1 nonegotiate isl trunking 1

thank you,

Bill

[Yudong Wu · Accepted solution]

1. I don't think you can negotiate a 10G port down to 1G. But on new SUP6-E, you can use "Twin gigabit converter modules" to convert a 10gig port to 2x 1 gig ports.

2. 15/1 and 16/1 is the internal port between switch side and MSFC.

HTH.

[Giuseppe Larosa · Accepted solution]

Hello Bill,

a) negative a 10GE has a physical layer so different that it cannot fallback to 1 GE.

However, for modern switches a twingig converter that gets two Ge ports from a 1 port 10 GE is available.

see

http://www.cisco.com/en/US/docs/switches/lan/catalyst3750e_3560e/hardware/install/notes/1757202.html

this could help in your case but you need to buy them

2)

this is CatOS hybrid mode C6500 with two supervisors

trunks 15/1 and 16/1 are the internal links to MSFC in supervisor #1 and MSFC in supervisor #2

you can check this with

sh module going down to submodules section you should see two MSFCs as 15 and 16 modules.

the numbers have been chosen so that even in a 6513 chassis cannot overlap with linecards

Hope to help

Giuseppe