[AzJazz]

I am trying to help a friend who has an Apple PC on a wired LAN.

The LAN has a DNS server located elsewhere on the network. His PC is connected directly with what looks like a TIA/EIA-T568B cable.

When his Apple PC is directly wired back to the router, the PC gets it's LAN TCP/IP address and other network configuration information fine.

However, the weird stuff starts when I try to add a switch into the mix. When I insert a switch between the PC and the normal LAN connection, I can't get any network configuration information or internet access - although there are flashing lights on the switch for both the LAN and PC connections.

Any ideas?

Thanks,

AzJazz

 

[nitroxp]

Hi AzJazz,

Is the switch managed?

I.E does it have VLANS / Layer 2 isolation setup on it?

Try a factory reset of the switch if you dont need the management.

Good Luck

 

[AzJazz]

The switch is a Cisco/Linksys EZXS55W 5-port Workgroup switch. I purchased it because it had MDI-X built in (figuring that it would remove at least one potential issue).

I just plugged it in straight from the box. I don't see where the EZXS55W is configurable - there isn't any information in the box on configuring it.

AzJazz

 

[Wand3r3r]

data sheet says it has a uplink port. did you connect to the uplink port? You should

 

[AzJazz]

data sheet says it has a uplink port. did you connect to the uplink port? You should

Hi, Wand3r3r -

Yes, I connected to the LAN connection to the Uplink port. I then connected the PC to ports 1-5, with no luck. The PC always configured for a 169.xxx.xxx.xxx address instead of a 192.168.xxx.xxx address when going through the switch.

AzJazz

 

[Wand3r3r]

I don't see mdi/mdix mentioned in the data sheet

http://downloads.linksysbycisco.com/downloads/datasheet/1224638754168/EZXS55W_V40_DS_B.pdf

connect instead to a lan port and see if it works then

 

[AzJazz]

I don't see mdi/mdix mentioned in the data sheet

http://downloads.linksysbycisco.com/downloads/datasheet/1224638754168/EZXS55W_V40_DS_B.pdf

connect instead to a lan port and see if it works then

Hi, Wand3r3r -

Hmmm. Well, the back of the box says, "Five 10/100 ports with auto MDI/MDI-X crossover detection". Not sure why the spec sheet doesn't show it. Hopefully, the box isn't lying.

I tried your suggestion of connecting the main LAN cable to one of the 5 ports (LAN on Port 4, PC on Port 3), and that didn't work, either. :4-dontkno

 

[Wand3r3r]

return the switch. It has to be defective.

 

[AzJazz]

return the switch. It has to be defective.

I'd really like to think that the switch was defective, but it is the third switch (all different models) I have tried on this network. All of them have had this problem.

I was hoping that the MDI-X auto detection might help, but it didn't.

AzJazz

 

[Wand3r3r]

Third switch???

Hook up the switch to the lan cable via the uplink port.
Connect via wire a laptop or a different pc [not the apple]

Does it work?

what the line goes to, is it a switch that has port authenication enabled?

 

[Troy_Jollimore]

How big is this network? Could it be running a network link protocol that possibly precludes rogue devices (ie. switches) from being recognized by the network?

Another thing to try is plugging the PC into the router so that it gets all of it's IP information through DHCP. Write it all down. Yes. ALL of it. Now, go and plug back into the switch. Now manually configure the LAN settings with the numbers you wrote down, and then see if it works.

 

[AzJazz]

Third switch???

Hook up the switch to the lan cable via the uplink port.
Connect via wire a laptop or a different pc [not the apple]

Does it work?

what the line goes to, is it a switch that has port authentication enabled?

Wand3r3r - I tried my laptop (A Dell WinXP machine), and saw the same results. Internet OK when directly connected, dead when going through the switch. I don't know about the port authentication - That's a good question. They may have turned that on, since the whole building is being fed by just a single T1 line (tiny bandwidth by today's standards).

How big is this network? Could it be running a network link protocol that possibly precludes rogue devices (ie. switches) from being recognized by the network?

Another thing to try is plugging the PC into the router so that it gets all of it's IP information through DHCP. Write it all down. Yes. ALL of it. Now, go and plug back into the switch. Now manually configure the LAN settings with the numbers you wrote down, and then see if it works.

Troy - Thanks! I tried that, still with no luck.

AzJazz

 

[Troy_Jollimore]

Port authentication or other security measures are more for security than to protect their bandwidth. It's so the IT admins can control more exactly just who accesses the network. Have you tried asking someone in the IT department if this is the case?

If your Dell also didn't work, and the numbers that DO work don't work, then connectivity if being denied at a more direct level.