[Gllug] bridging ports on a 3com switch

[Xander D Harkness]

John Hearns wrote:
> On Thu, 28 Nov 2002, Xander D Harkness wrote:
> 
> 
>>My brother who is still stuck at work trying to get a wireless link 
>>going has run into a couple of difficulties.
>>
>>He has four wireless aerials two on either side of the divide.
> 
> 
> Xander, a diagram would help here.
> 
A diagram is attached

It is channel bonding that is being used.  You are quite correct, the 
switches were purchased for this purpose.  They have worked at some 
point; however the behaviour they are exhibiting seemed very odd.

Obviously to ssh to a point there must be two way traffic; however this 
traffic may only be initiated from one side of the network.


Network X and Y are separated on the diagram to show two separate 
buildings.  They are both part of the same physical network 192.168.5.0/24

I can Ping from X to Y and SSH from a host in building X to Y.  I cannot 
do the reverse.

If A and B and C and D are swapped

I can then ping from Y to X and ssh from a host in Y to X but I can no 
longer ping from X to Y or ssh.

Kind regards
Xander
> 
>>He is trying to bridge two ports on a 3com switch
> 
>  either side to allow 
> Sorry, but smartness mode switches on here.
> What a switch is is a multi-port bridge.
> Before switches were popularised by (argghh! I forget the company name)
> ethernet was carried on shared coax cable, or by shared hubs.
> Segments were divided by two-port devices called learning bridges.
> Company XXX (arggh! I've used their kit) came up with the brilliant idea
> of using cheap ICs to create a 'hub' where each port was a bridge.
> So no more huge collision rates when there is a lot of data transfer.
> 
> 
> 
>>all four aerials to be used to double the bandwidth.
> 
> 
> 
> I am going to make an assumption here - what you want to do is to have
> twice the wireless bandwidth.
> In that case I think you need:
> (a) to set the antennas to run on different wireless channels explicitly,
> and make sure they are not on adjacent channels - I don't know how many
> channels apart they should be, but this is easy to look up.
> 
> (b) you need ethernet channel bonding, not bridging.
> A given switch may not necessarily do this.
> 
> 
> I may of course be talking nonsense - if the configuration your brother 
> has
> is not what I've imagined.
> 
> 
> 


-- 
It is better to kiss an avocado than to get in a fight with an aardvark.
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