Cisco 4507R+E to Cisco 3850 Migration

ed.warren · ‎05-30-2020

Good Morning,

I am at my wits end attempting to find out an issue I have with migrating a 4507R+e to a 3850 switch.

The 4507R+e is connected to the distribution switch (4510) which is connected to the firewall. I am running VLANs and the 4510 has a DFGW .254 for the VLAN on the 4507R+e. The 4507R+e has 30 computers connected to a patch panel Cat5e (T658B) and Cat5e (T658B) to the switch.

When I switch the Cat5e cable from the 4510 to the 3850 connectivity is good to the 4510 and can get out of the network. I connect a laptop directly to the 3850 I can get out the network and to the internet however when I connect one of the desktops that are connected via the patch panel - NO CONNECTIVITY.

I set auto to the MDIX and speed. I mimicked every setting on the 4507R+e and still nothing. Now here is the interesting part for me. If I drape a new cat5 cable across the room from the 3850 directly to the computer bypassing the patch panel I have connectivity.

Anyone have a clue what my issue could be? I am most appreciative of any assistance.

Ed

"A tech with a massive headache"

marce1000 · ‎05-30-2020

- There will probably be an on the edge cabling issue which the 3850 can not handle you need to check out cabling with a fluke , apparently the 3850 does not support TDR :

https://community.cisco.com/t5/networking-documents/how-to-use-time-domain-reflectometer-tdr/ta-p/3119327

M.

-- Each morning when I wake up and look into the mirror I always say ' Why am I so brilliant ? '
When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '

ed.warren · ‎07-19-2020

Good Morning M.,

My team and I was able to run the TDR test. Apparently the 3850 we have has the feature.

It does appear that the cables are crossed between the patch panel and a liskey box near the workstations. (See pic)

Giuseppe Larosa · ‎07-20-2020

Hello @ed.warren ,

>> It does appear that the cables are crossed between the patch panel and a liskey box near the workstations.

IF this is the case I would try to disable MDIX on the ports to see if without it the new switch port is able to build a working connection.

Hope to help

Giuseppe

ed.warren · ‎07-20-2020

Hello Giuseppe, You were definitely correct. As soon as MDIX was removed it connected up with no issues. Much, much appreciation. Thanks, Ed