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Understanding the different types of Ethernet Switches

Ivor Diedricks | June 3, 2014 at 9:43 am PST

445 pts (3 Comments)

Ethernet Switches are broadly categorized into two main categories – od!lar and "i#ed

Config!ration$

Moduar s!itc"es% as the name implies% allows yo! to add e#pansion mod!les into the switches as

needed% thereby deli&ering the best fle#ibility to address changing networ's$ E#amples of e#pansion

mod!les are applicationspecific (s!ch as "irewall% ireless% or *etwor' +nalysis)% mod!les for 

additional interfaces% power s!pplies% or cooling fans$ Cisco Catalyst 4, and -, are good e#amples

of od!lar switches$#i$ed %on&i'uration switches are switches with a fi#ed n!mber of ports and are typically not

e#pandable$ .his category is disc!ssed in f!rther detail below$ Cisco Catalyst /,% 3, and the

Cisco3001500 series are good e#amples of "i#ed Config!ration switches$

Let me say up front that there are variations to the categories below as switch makers are constantly 

adding capabilities and evolving the categories, but the broad essence remains the same.

.he "i#ed config!ration switch category is f!rther bro'en down into2

 – Unmanaged Switches

 – Smart Switches

 – anaged / and 3 Switches

(nmana'ed S!itc"es:

.his category of switch is the most cost effecti&e for deployment scenarios that re!ire only basic

layer / switching and connecti&ity$ +s s!ch% they fit best when yo! need a few e#tra ports on yo!r 

des'% in a lab% in a conference room% or e&en at home$

ith some Unmanaged switches in the mar'et% yo! can e&en get capabilities s!ch as cable

diagnostics% prioritization of traffic !sing defa!lt oS settings% Energy sa&ings capabilities !sing EEE

(Energy Efficient Ethernet) and e&en 6oE (6ower 7&er Ethernet)$ 8owe&er% as the name implies%

these switches generally cannot be modified1managed$ 9o! simply pl!g them in and they re!ire no

config!ration at all$

Cisco :00 Series switches are good e#amples of this category$

Smart S!itc"es (also 'nown as ightly anaged Switches)2

.his category of switches is the most bl!rred and fastest changing$ .he general r!le here is that

these switches offer certain le&els of anagement% oS% Sec!rity% etc$ b!t is ;lighter< in capabilities

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and less scalable than the anaged switches$ =t therefore ma'es them a costeffecti&e alternati&e to

anaged switches$ +s s!ch% Smart switches fit best at the edge of a large networ' (with anaged

Switches being !sed in the core)% as the infrastr!ct!re for smaller deployments% or for low comple#ity

networ's in general$

.he capabilities a&ailable for this Smart switch category &ary widely$ +ll of these de&ices ha&e aninterface for anagement – historically a browserbased interface !sed to be the only way to

config!re these de&ices% tho!gh nowadays yo! can manage some of these de&ices with C= and1or 

S*61>7* as well$ >egardless% these capabilities are lighter than what yo! will find in their 

anaged switch co!nterparts$ Smart switches tend to ha&e a management interface that is more

simplified than what anaged Switches offer$

Smart switches allow yo! to segment the networ' into wor'gro!ps by creating ?+*s% tho!gh with a

lower n!mber of ?+*s and nodes (+C addresses) than yo!@d get with a anaged switch$

.hey also offer some le&els of sec!rity% s!ch as A0/$:# endpoint a!thentication% and in some cases

with limited n!mbers of +Cs (access control lists)% tho!gh the le&els of control and gran!larity wo!ld

not be the same as a anaged switch$

=n addition% Smart switches s!pport basic !alityofser&ice (oS) that facilitates prioritization of 

!sers and applications based on A0/$:1.7S1BSC6% thereby ma'ing it !ite a &ersatile sol!tion$

Cisco /00 Series switches are good e#amples of this category$

#u) Mana'ed *2 and *3 s!itc"es:

anaged Switches are designed to deli&er the most comprehensi&e set of feat!res to pro&ide the

best application e#perience% the highest le&els of sec!rity% the most precise control and management

of the networ'% and offer the greatest scalability in the "i#ed Config!ration category of Switches$ +s

a res!lt% they are !s!ally deployed as aggregation1access switches in &ery large networ's or as core

switches in relati&ely smaller networ's$ anaged switches sho!ld s!pport both / switching and 3

=6 ro!ting tho!gh yo!@ll find some with only / switching s!pport$

"rom a Sec!rity perspecti&e% anaged switches pro&ide protection of the data plane (User traffic

being forwarded)% control plane (traffic being comm!nicated between networ'ing de&ices to ens!re

!ser traffic goes to the right destination)% and management plane (traffic !sed to manage the networ'

or de&ice itself)$ anaged switches also offer networ' storm control% denialofser&ice protection% and

m!ch more$

.he +ccess Control ist capabilities allows for fle#ibly dropping% rate limiting% mirroring% or logging of traffic by / address% 3 address% .C61UB6 port n!mbers% Ethernet type% =C6 or .C6 flags% etc$

anaged switches are rich in feat!res that enable them to protect themsel&es and the networ' from

deliberate or !nintended Benial of Ser&ice attac's$ =t incl!des Bynamic +>6 =nspection% =6&4 B8C6

snooping% =6&- "irst 8op Sec!rity with >+ !ard% *B =nspection% *eighbor Dinding =ntegrity% and

m!ch more$

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 +dditional Sec!rity capabilities may incl!de 6ri&ate ?+*s for sec!ring comm!nities of !sers or 

de&ice isolation% Sec!re anagement (downloads thro!gh SC6% ebbased +!thentication%

>adi!s1.+C+CS +++% etc)% Control 6lane 6olicing (Co66) for protecting the C6U of the switch%

richer s!pport for A0/$:# (timebased% Bynamic ?+* +ssignment% port1hostbased% etc)

"rom a Scalability perspecti&e% these de&ices ha&e large table sizes so that yo! can create largen!mbers of ?+*s (for wor'gro!ps)% de&ices (+C table size)% =6 ro!tes% and +C policies for flow

based sec!rity1oS p!rposes% etc$

"or highest networ' a&ailability and !ptime% anaged switches s!pport 3 red!ndancy !sing ?>>6

(?irt!al >o!ter >ed!ndancy 6rotocol)% large n!mbers of in' +ggregation gro!ps (which is !sed

both for scalability and resiliency)% and capabilities for protecting / s!ch as Spanning .ree >oot

!ard and D6BU !ard$

hen we tal' abo!t oS and !lticast feat!res% the richness of capabilities goes far beyond what

yo!@d see in a Smart Switch$ 8ere yo!@d see things s!ch as =6 and B Snooping with !erier 

f!nctions for optimizing =6&41&- m!lticast traffic in the +*% .C6 Congestion +&oidance% 4 or A

!e!es to treat traffic differently by importance% setting1tagging traffic by / (A0/$:p) or 3

(BSC61.7S)% and rate limiting traffic$

=n terms of anagement% things s!ch as m!ltiple ways to config!re (!sing C=% eb U=% S*6

anagement application)% disco&ering of neighbor de&ices in the networ's (!sing CB6% B6%

Dono!r% etc)% and tro!bleshooting capabilities (s!ch as ?+* and 6ort irroring% .racero!te% 6ing%

Syslog% Cable Biagnostics% >7*% etc) are all incl!ded$

hat = highlighted is by no means e#ha!sti&e% b!t gi&es yo! a sense of what some of the differences

may be between anaged and Smart Switches$

Cisco Catalyst and Cisco 300 Series and 500 Series switches are good e#amples of this category of 

prod!cts$

anaged Switches can go e&en f!rther than what =@&e highlighted$ "or e#ample% there@s e&en richer 

s!pport for Bynamic Unicast and !lticast >o!ting protocols% deeper flow intelligence or macro flow

statistics with *etflow1S"low% nonStop "orwarding capabilities% 6S1?>" s!pport% 6olicy

enforcement% and many others$

*ow% to ta'e a deeper di&e into these switch categories and tal' abo!t &ario!s options% yo! can

select the switches based on2

 – Speed

 – *!mber of ports

 – 67E &ers!s non67E

 – Stac'able &ers!s Standalone

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S+eed:

9o! can find "i#ed Config!ration switches in "ast Ethernet (:01:00 bps)% igabit Ethernet

(:01:001:000 bps)% .en igabit (:01:001:0001:0000 bps) and e&en some 401:00 bps speeds$

.hese switches ha&e a n!mber of !plin' ports and a n!mber of downlin' ports$ Bownlin's connect

to end !sers – !plin's connect to other Switches or to the networ' infrastr!ct!re$ C!rrently% igabit is

the most pop!lar interface speed tho!gh "ast Ethernet is still widely !sed% especially in pricesensiti&e en&ironments$ .en igabit has been growing rapidly% especially in the datacenter and% as

the cost comes down% it will contin!e to e#pand into more networ' applications$ ith :0Dase. .en

igabit copper interfaces being integrated into 7 (+* on the otherboard) and :0Dase.

switches becoming a&ailable now (see the new Cisco S500FA"A. :-port :0igabit switch)%

b!ilding a Storage or Ser&er farm with :0 igabit interfaces has ne&er been easier or more cost

effecti&e$ 401:00 is still emerging and will be mainstream in a few years$

um-er o& +orts:

"i#ed Config!ration Switches typically come in 5% A% :0% :-% /4% /A% 4A% and 5/port config!rations$

.hese ports may be a combination of S"61S"6G slots for fiber connecti&ity% b!t more commonly they

are copper ports with >H45 connectors on the front% allowing for distances !p to :00 meters$ ith

"iber S"6 mod!les% yo! can go distances !p to 40 'ilometers

P./ versus nonP./:

6ower o&er Ethernet is a capability that facilitates powering a de&ice (s!ch as an =6 phone% =6

S!r&eillance Camera% or ireless +ccess 6oint) o&er the same cable as the data traffic$ 7ne of the

ad&antages of 6oE is the fle#ibility it pro&ides in allowing yo! to easily place endpoints anywhere in

the b!siness% e&en places where it might be diffic!lt to r!n a power o!tlet$ 7ne e#ample is that yo!

can place a ireless +ccess 6oint inside a wall or ceiling$

Switches deli&er power according to a few standards – =EEE A0/$3af deli&ers power !p to :5$4 atts

on a switch port whereas =EEE A0/$3at (also 'nown as 67EG) deli&ers power !p to 30 atts on a

switch port$ "or most endpoints% A0/$3af is s!fficient b!t there are de&ices% s!ch as ?ideo phones or 

 +ccess 6oints with m!ltiple radios% which ha&e higher power needs$ =t@s important to point o!t that

there are other 6oE standards c!rrently being de&eloped that will deli&er e&en high le&els of power 

for f!t!re applications$ Switches ha&e a power b!dget set aside for r!nning the switch itself% and also

an amo!nt of power dedicated for 67E endpoints$

.o find the switch that is right for yo!% all yo! need to do is choose a switch according to yo!r power 

needs$ hen connecting to des'tops or other types of de&ices which do not re!ire 67E% the non

67E switches are a more costeffecti&e option$

Stacka-e versus Standaone: +s the networ' grows% yo! will need more switches to pro&ide networ' connecti&ity to the growing

n!mber of de&ices in the networ'$ hen !sing Standalone switches% each switch is managed%

tro!bleshot% and config!red as an indi&id!al entity$

=n contrast% Stac'able switches pro&ide a way to simplify and increase the a&ailability of the networ'$

=nstead of config!ring% managing% and tro!bleshooting eight 4Aport switches indi&id!ally% yo! can

manage all eight li'e a single !nit !sing a Stac'able Switches$ ith a tr!e Stac'able Switch% those

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eight switches (total 3A4 ports) f!nction as a single switch – there is a single S*61>7* agent%

single Spanning .ree domain% single C= or eb interface – i$e$ single management plane$ 9o! can

also create lin' aggregation gro!ps spanning across m!ltiple !nits in the stac'% port mirror traffic

from one !nit in the stac' to another% or set!p +Cs1oS spanning all the !nits$ .here are &al!able

operational ad&antages to be gained by this approach$

8ere@s a word of warning$ De caref!l abo!t prod!cts in the mar'et which are sold as ;Stac'able<

when they merely offer a single !ser interface% or central management interface% for getting to each

indi&id!al switch !nit$ .his approach is not stac'able% b!t really ;cl!stering<$ 9o! still ha&e to

config!re e&ery feat!re s!ch as +Cs% oS% 6ort mirroring% etc% indi&id!ally on each switch$ Use the

following as a proof point – can = create a lin' aggregation gro!p with one port in one !nit of the

stac' and another port of that gro!p in another !nit of the stac'I Can = select a port on one !nit in

the stac' and mirror the traffic to a port on another !nit of the stac'I hen = config!re an +C for 

Sec!rity p!rposes% can = apply that to any port on any !nit in the stac'I =f the answer is ;*o< to any

of these !estions% yo!@re probably not wor'ing with a stac'able switch$

.here are other ad&antages of .r!e Stac'ing as well$ 9o! can connect the stac' members in a ring

s!ch that% if a port or cable fails% the stac' will a!tomatically ro!te aro!nd that fail!re% many times at

microsecond speeds$ 9o! can also add or s!btract stac' members and ha&e it a!tomatically

recognized and added into the stac'$

Cisco Catalyst /,F and 3, or Cisco 500 Series Switches are e#amples of Switches in this category$

 As you can see there’s a multitude of switch options to choose from. So, have a close look at your 

current deployment and future needs to determine the right switch for your network.