No link between GigabitEthernet and FastEthernet ports

[Ricky S]

Hello everyone, I am having a bit of a weird issue. I have a Cisco Aironet 1142 AP with a Gig port (GigabitEthernet0) and a Cisco 3548XL switch with FastEthernet ports. When I connect the two together, I do not get any link lights. I have tried playing with the Speed and Duplex settings on both ends by winding down AP side to speed 100 but no luck. I am using a straight-thru cable.

Any ideas?

[ashirkar]

Hi Ricky,

I m not sure cisco 3500XL are POE supportable.

If your switch has a module capable of providing  PoE to end stations, you can set each interface on the module to  automatically detect and apply PoE if the end station requires power.

Try out this command

Switch# conf t 

Switch(config)# int gig1/1

Switch(config-if)# power inline auto

Thanks 
Ashish 

[Sandeep Choudhary]

Hi Ricky,

NO need to change the settings of the port.

you can connect a AP on switch interface and run away.it works like this.

Just put the port in the right vlan.

Switch#config t

Switch(config)#int fa0/1

Switch(config-if)#switchport access vlan x

Regards

[jimmysands73_2]

I think the above poster input about inline power will work, definite place to start.   But now that I think about it, no POE on a 3548 xl, you would need a  WS-C3524-PWR-XL-EN.  I do not believe that a 48 port 3548 POE sw was ever made, could be wrong.

Sandeep...you are looking at layer2/3, the poster cannot get past layer 1.

[Ricky S]

Thanks guys. I forgot to mention this AP is being fed power by a power injector therefore no need for POE. Currently it is plugged into an HP 3COM Baseline Switch 2848 which I am here to remove. When it's plugged into the 3COM, link comes up and everything works. However I need to pass another VLAN to the AP in order to get my second SSID to work.Therefore I am trying to trunk it with the Cisco switch right beneath. However I can't get past layer 1.

[Ricky S]

Fixed!

I was able to relocate the AP and plug it directly into the switch with the power injector connected, and link came up. Weird :s

Thanks for all the responses guys.

[Leo Laohoo]

 I am using a straight-thru cable.  Any ideas?

Cross over.

When it's plugged into the 3COM, link comes up and everything works.

I'm not an expert with 3Com switches but I believe this particular switch is MDI/MDI-X while the very, very older 3500XL doesn't even know what the meaning of MDI/MDI-X means.