[NTLUG:Discuss] what is the problem?

[Chris J Albertson]

You've done a lot of the debugging I would have done to this point.
When connecting switches, it's either regular port to uplink via
straight-thru cable... or regular port to regular port via cross-over
cable.
Since You're doing the regular port on switch A to uplink on B, you have a
straight-thru. If it works when you just replace switch B with a PC, then
I'd say switch A and the straight-thru cable work fine.
Now, if you get the same results with switch C uplink port, I would have
to say that you've got something wrong with the uplink configuration of
switches B and C. I doubt switch A has anything to do with this, nor do I
think it's the cable.
One thing I would do for sure is remove all devices from all the switches.
If these are truly switches as you say, then you have some software
configuration to start looking at. You may have some virtual LAN setups or
such going on. I dunno.
Another thing to try is to get switches B and C talking. If you can get
those switches to connect, then start adding devices to them. You may
find, as mentioned by someone else, that your cable modem is hurting you.

In my experience with getting switches and hubs to talk on the same
subnet, bad uplink connections usually identify themselves with no link
light at all. This is the puzzling part.

Good luck!

Chris


Kelledin said:
> Your cable modem should be connected directly to a router, not
> sitting on a switch.  Having it sitting on your network like
> just another networked PC may work, it may not.  Even if it
> seems to work, it may force certain limitations.  If PCs on
> Switch A are able to reach PCs on Switch B (and vice versa), but
> not all of them can use the cable modem, this is likely to be
> your problem.  Your solution in this case would be to set up a
> router (preferably Linux on an old 486 with two Ethernet cards).
>
> If PCs on Switch A are _not_ able to reach PCs on Switch B, then
> you need to check a few things:
>
> 1) See if disconnecting the cable modem allows the two switches
> to work properly together.
> 2) See if the uplink port being used requires a crossover
> connection (versus the more standard straight-through).  Some
> 10baseT and Fast Ethernet switches require this; copper Gigabit
> switches should not.
> 3) Make sure the uplink port being used is actually set to work
> as an uplink port.  Most switches have a setting that can force
> the uplink port to work just like any other port.
>
> On Monday 29 July 2002 01:33 pm, m m wrote:
>> Hi All:
>>
>> I have a problem on internet connection, please help.
>>
>> switch A connect to cable modem, switch A is about 100-150
>> feet aparts for PCs and switch B. the connection cable are two
>> cat5 with inline receptacle. I can connect from network switch
>> A to any of my PCs, it works. I use the same wire to connect
>> to network switche A (regular) to Switch B (uplink), it does
>> not work. the switch A light is on (indicate good), the switch
>> B uplink light is blinking (indicates collusion) I use the
>> same wire to connect to network switche A (uplink) to Switch C
>> (regular), it does not work either. the switch A, the switch B
>> lights are blinking (indicates collusion)
>>
>> any one have a clue?
>>
>> thanks.
>>
>>
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> --
> Kelledin
> "If a server crashes in a server farm and no one pings it, does
> it still cost four figures to fix?"
>
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