Re: [LARTC] Linux bridging and cascaded switches

[John Default <default@advaita.sytes.net>]

Hi

Greg Scott wrote:
> More fundamentally, can I cascade these switches and my bridge/firewall
> this deep?  How do the Internet router and internal servers find each
> others' MAC addresses when they are 4 "hops" (OSI layer 2 hops)
> separated?  Or am I making this too complicated?
>
>   
i was taught that you should have no more than 4 switches between any 
two LAN nodes, so this should work. STP should be ok, but not needed 
until you have some redundant links between bridge/fw and core switches 
(if you have more core switches, you would probably like to use more 
links for redundancy).
[you would probably want the core switch to become STP root then.. ]

when switch doesn't know destination it works like hub, so at the 
beginning your network will be flooded with frames and this way all 
switches will learn mac addresses no matter how many hops. (frame will 
be broadcasted to all corners of LAN).

servers and router will search for each other's MAC using ARP 
broadcasts, which will get to every node in LAN (if you don't filter 
them out : ) ). Therefore they will certainly find each other.
 
(( 4 switches add constant delay to your traffic that i think you would 
like to avoid.  if you could make internet router a firewall (you 
probably can't : ) ), that would remove 2 layers of bridging, would be 
more simple and allow more control.

servers--distribution_switch--core_switch--router/firewall
                                                     |
                                                internet switch
))
>> Internal---User---Core-----Firewall---Internet---Internet router
>> Servers   switch  switch  (Bridged)    switch   (and default GW for
>>                                                  internal servers)
>>     
>
> Thanks
>
> - Greg
>   
___________________________________

S pozdravom / Best regards

John Default
__________________________________

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