[AusNOG] Stackable Switching and Network Redundancy

[Joseph Goldman]

Hi List,

  I wish to use stacked switching (2 units) for redundancy.

  I have 2 switches that I plan to stack, and 2 routers configured in a 
LB+HA arrangement. I would like each router to have connection with each 
of the physical switches, for the redundancy in case a single switch dies.

  I have been debating about best way to achieve this, whether just 
simply plugging the 2 ports in, bridging on the router end and allowing 
the router + switch platform to decide which link should actually be 
used, or using something like LACP. In a non LACP setup, will the switch 
platform be smart enough to recognise that the device I'm trying to 
reach plugs into physical switch 1, so it will send the appropriate data 
via that switch port? Trying to avoid 'flooding' the stacking backplane 
(not that I will be transporting that much data, but better to design 
appropriately now).

  LACP seems the more appropriate way to go, but I wasn't sure on 
peoples experiences in the sense of the data having to cross the 
stacking backplane, and having 'out-of-sequence' kind of problems.

  For reference - the stacking platform I am considering testing on is 
SMC 8848M 'TigerStack II' with RouterOS routers.

  I am also interested in peoples general opinions/experiences on the 
SMC's. I have used them stand-alone, and preferred the Cisco switches we 
now have in place, but our current Cisco platform does not support 
stacking, and rather than pushing for budget for new platform, thought 
we may try utilise devices we already have on hand.
  I found the CLI 'slow' and very clone-ish to Cisco - which frustrated 
me as I was used to Cisco but the small differences caught me up. This 
is less a fault of the switch rather than personal preference.

Thanks,
Joe