duplex full 100 problem 6748-GE

[antonio.dinapoli]

Hi,

I have a strange problem with duplex mode.

I have a Cisco 7606 with RSP720-3C-GE (IOS advanced ip services 12.2(33)SRD2a) and a 6748-GE-TX 48 port 10/100/1000 module (firmware 12.2.(14r)S5).

On 6748-GE-TX module, I have some ports that operate in half duplex 100 when they are connected to some other network devices (not Cisco) that are set in full duplex 100 (no negotation).

When I try to set speed 100 duplex full on Cisco 7606, links disconnect.

If I set autonegotiation on network device, nothing changes: link operates in half duplex 100 or becomes disconnected.

If I connect the network device on another copper module (Cisco 6148A-GE-TX) that is installed on the same 7606, link continues to operate in half duplex 100 when port is in autonegotiation mode but the big difference with previous module is that port begins to operate in 100 full when I set speed and duplex.

Is there any bug on  firmware release of the 6748 module?

Is it possible to resolve this behavior with an IOS update?

Anyone can help me?

thanks in advance

antonio

[more_jazZz_2]

Hi, Antonio

What cable you use crossover or straight? And what show command “show interfaces transceiver properties”?

Best regards,

Zak.

[NickNac79 · Accepted solution]

Hi Antonio,

When you set either Speed or Duplex on a port, unfortunately Auto-MDIX also gets turned off.  It's completely bonkers, and for no good reason, but that's the way it is.

You'll need to swap your Straight cable for a crossover or vice-versa.

Hope that helps,

Nick

[antonio.dinapoli]

Thanks for yours answers.

I swap straigth cable for a crossover, then I set speed 100 and duplex full and link becomes connected.

So now I can use also ports on 6748-GE-TX module.

antonio