Speed/Duplex Mismatch issue

[Zeeeee]

Hi All,

This is my setup:

Scenario 1:

Port1/48 of 3750 - Speed 100/Duplex Full

Port1/48 of 6509 - Speed auto/Duplex auto

Link is up.

Scenario 2:

Port1/48 of 3750 - Speed auto/Duplex auto

Port1/48 of 6509 - Speed 100/Duplex Full

Link is up.

Scenario 3:

Port1/48 of 3750 - Speed auto/Duplex auto

Port1/48 of 6509 - Speed auto/Duplex auto

Link is up.

Scenario 4:

Port1/48 of 3750 - Speed 100/Duplex Full

Port1/48 of 6509 - Speed 100/Duplex Full

Link is down.

I wanted to set it to 100/duplex for both switches but the link fails to be up. Did i miss anything?

Thank you,

Aizat

[Mark Malone]

Is there anything in place between the 3750 and 6509 in scenario 4 , like hub unmanaged switch , riverbed etc  or is it a direct link between the 2 switches ?

[Zeeeee]

Hi Mark,

It is a direct link with nothing in between.

[chrihussey]

Are they gigabit or 100mb interfaces?

[Zeeeee]

Hi Chrihussey,

3750 is 100mb while 6509 is 1gb.

[chrihussey]

So if you configure both hard coded as 100/Full maybe you could try a cross over cable. You would need that if they were both native 100mbs.

[Mark Malone]

both those switches should be new enough to support auto mdix for straight through cables would have thought unless it turned off

[Mark Malone]

If its not mdix is the cause what does the show interface g1/48 capabilities show when the interface is hardcoded

[Zeeeee]

Hi Mark,

Am i right to say that i do not think it is a mdix issue as the link is up with auto/auto to 100/full?

[Mark Malone]

Yes true actually id still make sure its on , if its it up its up whether auto or hardcoded , mdix job is only to convert if required its doesn't base itself on speed settings as far as I know , what does the capabilities show when its configured , is it stating its set right

#sh int g1/4/1 capabilities
GigabitEthernet1/4/1
  Model:                 WS-X6748-SFP
  Type:                  1000BaseSX
  Speed:                 1000
  Duplex:                full
  Trunk encap. type:     802.1Q

[Zeeeee]

Hi Mark,

I am out now. Will show you the output in 2hr time.

[Mark Malone]

Hi did you get any further with this

[Zeeeee]

Hi Mark,

Sorry I didnt realize you message. But as suggested, i set it as auto/auto.

Do let me know if you still want me to show the output of the properties as you mentioned above.

[Mark Malone]

ah no that's grand if its working auto/auto best to leave it as it is the recommended way , I was just interested to see why it wasn't working at hardset if you were still trying to set it that way

[Zeeeee]

Hi Mark,

Thank you for assisting!