What sort of network would benefit from switch stacking? Are there any drawbacks to taking this approach? What would be an alternative to stack switches?
There are two ways of connecting multiple switches together:
a) Cascade: You connect port of a switch to a port of another switch. This way, you are looking at two independent switches connected to each other (with their independent IP numbers if given). Regular Ethernet cable (copper or fiber) is used for such connections.
b) Stack: You connect the special stacking port (usually at the back) of one switch to the special stacking port of another switch. Usually, these stacking ports have more bandwidth than the front 10 or 100 or 1000 Mbps ports. Special, thick, stacking cables are used for such connections.
Switches stacked together look like a "single switch" and are managed with a single IP address.
But with the recent availability of 10 or 40 or 100 Gbps ports it has been common usage to stack switches via their uplink ports. This tecnique also enables long distance stacking by using fiber interfaces and fiber cabling.
Using these high bandwidth uplink ports, I don't see too much difference/usage between cascade connection and stack connection.
However, recent technologies enable stacked switches to form redundant backbone topologies using Link Aggregation Control Protocol (LACP).
Switch1 ---- Switch2
Switch3 Switch4 .... Switch15
Switch1 and Switch2 are stacked together. Switch3, Switch4, ... are connected to both of them. These two lines connected to Switch1 and Switch2 can be grouped together under LACP because stacked Switch1 and Switch2 act like a single switch.
This way, if either of the two backbone switches fail (Switch1 or 2), the other switch will still provide connectivity to edge switches (Switch3, 4, ...).
Better alternative to stacking will be using a chassis switch. It is a better alternative because chassis switch backplane usually has more bandwidth compared to 10 or 40 or 100 Gbps connections of a stacked group of switches.
Disadvantage of a chassis switch will be its high price. Usually chassis switch power supplies and line cards are epensive. Chassis switch control cards are even more expensive.
Thanks @Ender Kefoglu, this is a really helpful answer!
Stack switches will save multiple IP, a single IP will use for complete stack and get more ports on switch. No need to manage multiple switches. single adminsitation.
Stack switches are useful mainly in configuration - they appear to the rest of the network as one single switch, making them easier to configure.