WS-C2960X-48FPS-L and SFP support Auto MDI/MDX or is crossover needed?

[Jason Aarons]

I have two WS-C2960X-48FPS-L running c2960x-universalk9-mz.150-2.EX5 and using two GLC-Ts in each switch etherchanneled together.

I put a straight-thru cable in and SW1 shows up/up and SW2 shows down/line protocol down. Do I need a cross-over cable?

Nothing is in err-disable.  I did a shut and not shut on all interface and still one side is up/up and other side is down/down.  Really odd.

Both sides have exact identical config.  

2960X02#show run int gig1/0/50
Building configuration...

Current configuration : 144 bytes
!
interface GigabitEthernet1/0/50
 description Uplink to 2960X-01
 switchport mode trunk
 speed 1000
 duplex full
 channel-group 1 mode on
end

2960X02#show run int gig1/0/52
Building configuration...

Current configuration : 144 bytes
!
interface GigabitEthernet1/0/52
 description Uplink to 2960X-01
 switchport mode trunk
 speed 1000
 duplex full
 channel-group 1 mode on
end

[Reza Sharifi]

Straight through cable should work just fine.

Try this, delete both all interface from the Portchannle and test to see if they come up.

no channel-group 1 mode on

HTH

[Jason Aarons]

Removed the channel-group 1 mode on, no difference. Leaving the channel-group off the config.

Shut all ports, then no shut all ports.  Still down/down.
 

[Martin Carr]

Technically, a cross over cable is required.

However, with 'MDIX', you can use a straight through, when you configure speed parameters etc it disables this feature, is there a reason why you need to do this?

Set both to auto...

Martin

[Leo Laohoo]

The issue is your IOS.  There's a known "bug" with 2960X running EX5.  Downgrade your IOS to EX4.

[yusuf habibi]

Hi Leo,

i think is not bug, i have same situation with that when i trying to hardcode (speed & duplex) on interface both of switches. if the interface using auto is look like a normal.

my opinion, if we want to harcode the interface both of switches we need cross-over cable eventhough the switches has auto MDIX or one of switch is auto (speed & duplex).

SW1 hardcode < mode trunk  > SW2 harcode (with cross-over cable) up/up
SW1 hardcode < mode trunk > SW2 auto (with straight) up/up

[Leo Laohoo]

MDI/MDI-X gets disabled if you configure speed or duplex or both.

[Jason Aarons]

What is the bug id?  I'm not able to find a match in the bug toolkit -jason

[Leo Laohoo]

Jason, 

I remembered seeing a few posts regarding 2960X and a lot of SFP issues (HERE).  The only solution was to downgrade to EX3 or EX4.  

Ok, now here's the rub:  EX4 was INITIALLY the solution to solve this issue regarding SFP/SFP+ issues with 2960X.  The rub is even EX4 people started seeing MORE issues (other than SFP/SFP+).  So the final "recommendation" is to go further down to EX3.  

Personally, I wouldn't recommend anyone use 15.2(2)E.  If you have to use 15.2(2)E then be careful.  If you have 802.1x and PoE phones, AVOID 15.2(2)E or who-do-you-call (you won't be able to call someone.  LITERALLY!)?

[Jason Aarons]

There is not a EX4 on cisco.com.  Only the c2960x-universalk9-tar.150-2.EX5.tar or the c2960x-universalk9-tar.152-2.E.tar.

[Leo Laohoo]

Jason, 

There WAS an EX4. 

Try use EX3 instead.