3650 ports not coming up with end clients/devices

[phil_carter]

Hello,

We have migrated some 3750s to new 3650s and seen serious connectivity issues when re-patching Windows 7 clients and servers across from old to new. The same config is applied but the ports never come up. The workaround is to default the interface configuration and then re-apply all but the 'speed 100' setting:

interface GigabitEthernet1/0/20
 switchport access vlan 4
 switchport mode access
 switchport voice vlan 501
 duplex full
 no snmp trap link-status
 no mdix auto
 storm-control broadcast level 5.00
 storm-control multicast level 30.00
 spanning-tree portfast

YARNTN_A_CC365_01(config-if)#do sh int g1/0/20 status
Port Name Status Vlan Duplex Speed Type
Gi1/0/20 connected 4 half a-100 10/100/1000BaseTX

The duplex setting is also mismatched on the switch - even though hard coded full, it comes up as half. By adding 'speed 100' it drops the connection altogether.

Details:

PID: WS-C3650-24PS     , VID: V02

Switch Ports Model              SW Version        SW Image              Mode
------ ----- -----              ----------        ----------            ----
*    1 28    WS-C3650-24PS      03.03.04SE        cat3k_caa-universalk9 INSTALL

Anyone seen this problem and know of a fix?

Thanks

Phil

[Leo Laohoo]

Uhhhh ... Dude, MDIX is TURNED OFF.  WTF!

One has got to be nuts to turn of MDIX.  

[phil_carter]

mdix auto only affects whether a straight or cross-over cable is required. The same config has been applied on the 3650 that was on the 3750 with same cable and end device.

Also, I believe if you turn this on, you must set speed/duplex to auto as well, which is not our company policy (introduces risk of half duplex connections to end devices that have set speed and duplex). That and not all end devices support the mdix feature anyway.

[Leo Laohoo]

which is not our company policy (introduces risk of half duplex connections to end devices that have set speed and duplex). 

Your company policy must be written during the stone age.  

Back 10 years ago, I agree about setting duplex and speed settings.  Nowadays, unless you are looking to slow down and severely hinder the performance of the network, no one hard codes speed and duplex settings.  

Also, I believe if you turn this on, you must set speed/duplex to auto as well

MDIX is like BPDU Guard.  It is a friend and not to be treated like a plague.

NOTE:  Your colleague, Chris Ayres, has opened another thread.  

[glen.grant]

 For one device I would try the setting on the port as auto . My guess is you have clients that are set as auto and thus if you are hardcoding the switch you have mismatches then which cause half duplex connections . If you need to hardcode the switch then you are going to have to run around and verify every single pc nic setting is hardcoded to 100/full also .