Mpls Session

8/18/2019 Mpls Session

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Manoj Wadhwa

18

th

Oct 2008

Multi Protocol Label Switching

(MPLS)


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Agenda

Why we need MPLS

MPLS Concepts

Label Assignment !ist"ib#tion

$"ame Mode MPLS concepts implementation

MPLS monito"ing

MPLS %P&s


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'ow "o#te"s (o"wa"d pac)ets


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P"ocess Switching *+ ,"aditional method o( (o"wa"ding

pac)ets- $#ll loo)#p o( e.e"y pac)et- &o longe" #sed now-

/ach e.e"y pac)et is p"ocessed by the "o#te" p"ocesso"-

'ence it is .e"y slow-

$ast Switching *+ sed #ntil 200+200- $i"st pac)et is

p"ocess switched a(te" which in(o"mation is mo.ed in the

cache- S#bse3#ent pac)ets doesn4t loo)#p the "o#ting

table "es#lting in (aste" (o"wa"ding o( pac)ets- 5t had

limitations li)e pe" pac)et load sha"ing was not s#ppo"ted-


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Cisco /6p"ess $o"wa"ding 7C/$ *+ /liminates 1st pac)et

iss#e o( (ast switching- 5t p"e+b#ilds the cache- 5t c"eates

$59 7$o"wa"d 5n(o"mation 9ase and Adjacency table which

p"emaps the ne6t hop ip add"ess ne6t hop Mac add"ess-

5t s#ppo"ts pe" pac)et load sha"ing- 'owe.e" it had

d"awbac)s li)e it "e3#i"es mo"e memo"y and is Cisco

p"op"ieta"y


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,"aditional 5P (o"wa"ding

,"aditional 5P (o"wa"ding is based on *+

:o#ting p"otocols #sed to dist"ib#te laye" "o#ting

in(o"mation

$o"wa"ding based on the destination add"ess only

:o#ting loo)#ps pe"(o"med on e.e"y hop


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Why we need MPLS

5( yo# want C/$ style speed going th"o#gh a 5SP netwo")

which has non+Cisco "o#te"s; that4s whe"e MPLS comes

into pict#"e- 5t allows "o#te"s to ha.e e6t"emely (ast laye" 2

style (o"wa"ding on non+Cisco e3#ipment- So MPLS is

basically li)e an added (eat#"e in a "o#te" that allows it to

go m#ch (aste" than typical "o#ting p"otocols wo#ld- 5t

allows all o( the (o"wa"ding to happen at Laye" 2-

/ssentially the "o#te" becomes as (ast as a switch-


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What is MPLS

5nd#st"y standa"d mechanism

$o"wa"ding decisions based on laye" 2 labels

Labels can co""espond to *+ !estination netwo")

So#"ce add"ess


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9asic MPLS concepts


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MPLS e6ample


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MPLS components

MPLS has two majo" components

Cont"ol plane

Whe"e Laye" "o#ting p"otocols e6ists 7OSP$; /5=:P etc

Whe"e label e6change p"otocols e6ists 7,!P; L!P etc

!ata plane

Also )nown as (o"wa"ding plane

Sends data based on L o" L2 in(o"mation ,a)es ca"e o( label swapping


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MPLS A"chitect#"e


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MPLS Labels

MPLS ,echnology is intended to be #sed anywhe"e

"ega"dless o( Laye" 1 media and Laye" 2 p"otocol

MPLS #ses a 2+bit label (ield that is inse"ted between

Laye" 2 and Laye" heade"s 7("ame > mode MPLS o.e" A,M #ses the A,M heade" 7%P5? %C5 (ield as

the label 7Cell+mode

Labels ha.e local signi(icance

Label allocations a"e asynch"ono#s


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MPLS Label (o"mat


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MPLS Label (o"mat


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MPLS Label Stac)


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Common MPLS ,e"ms

Label Switch :o#te" 7LS:

/dge LS:

Cont"ol Plane

!ata Plane

Label !ist"ib#tion P"otocol 7L!P

$o"wa"ding 5n(o"mation 9ase 7$59

Label 5n(o"mation 9ase 7L59

Label $o"wa"ding 5n(o"mation 9ase 7L$59

Label Switched Path 7LSP


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Common MPLS ,e"ms

L59 *+ ,he L59 (#nctions in the cont"ol plane and is #sed by

the L!P whe"e 5P destination netwo") in the "o#ting table

a"e mapped to the ne6t hop labels that a"e "ecei.ed ("om

downst"eam "o#te"s as well as local labels gene"ated by

the L!P

L$59 *+ ,he L$59 "esides in the data plane contains a

local label to ne6t hop label mapping along with o#tgoing

inte"(ace which is #sed to (o"wa"d labeled pac)ed-

LSP *+ LSP is a se3#ence o( LS:4s that (o"wa"d labeled

pac)ets


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Common MPLS ,e"ms

5n(o"mation abo#t "eachability to destination netwo")s ("om

"o#ting p"otocols is #sed to pop#late the "o#ting table- ,he

"o#ting table in t#"n p"o.ides in(o"mation (o" the $59- ,he

L59 is pop#lated #sing in(o"mation ("om L!P and ("om L59

along with $59; L$59 is pop#lated-


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LS: A"chitect#"e


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/dge LS: A"chitect#"e


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MPLS P"ocess

:o#te"s b#ild the "o#ting table

,he MPLS > enabled "o#te"s assign labels to each "o#te

,he "o#te"s ad.e"tise thei" labels to othe" LS:4s

All LS:4s b#ild thei" $59; L59 and L$59

&ote *+ MPLS is almost li)e "#nning a second p"otocol on top

o( e.e"ything- &ow we ha.e an e6t"a "o#ting p"otocol that4s

sending labels which has e((ecti.ely b"o#ght "o#ting to alaye" 2 label p"ocess ma)ing "o#te" almost as e((icient as a

switch when they a"e sending the data


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MPLS P"ocess


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MPLS P"ocess


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Pen#ltimate 'op Popping 7P'P

MPLS pe"(o"mance is optimi@ed by the #se o( P'P


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Loop P"e.ention


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&o"mal ,,L p"opagation


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!isabling ,,L p"opagation


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,"ace"o#te with ,,L disabled


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5mpact o( disabling ,,L p"opagation


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L!P Session establishment


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MPLS $"ame mode con(ig#"ation

9elow a"e the steps to enable $"ame mode MPLS

Acti.ating 5P C/$

/nabling inte"(aces (o" MPLS

,#"ning on the L!P

5nc"easing the M,

%e"i(ication


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Con(ig#"ing MPLS


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Con(ig#"ing MPLS


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Con(ig#"ing 5P ,,L P"opagation


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5P ,,L p"opagation


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5P ,,L p"opagation

With ,,L p"opagation disabled; the t"ace command

displays only the ing"ess p"o.ide" "o#te" 7and sometimes

the eg"ess p"o.ide" "o#te"-


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5P ,,L p"opagation


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5P ,,L p"opagation

Selecti.e 5P ,,L p"opagation hides the p"o.ide" netwo")

("om the c#stome" b#t still allows t"o#bleshooting


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MPLS monito"ing commands


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nde"standing MPLS %P&


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!"awbac)s o( t"aditional %P&s

O.e"lay %P& *+ Costly i( (#ll mesh connecti.ity is "e3#i"ed

Pee"+Pee" %P& *+ Client "elies on se".ice p"o.ide" (o" "o#ting-

SP "#ns the challenge o( 5P add"esses-


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MPLS %P&4s


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MPLS %P&4s

MPLS %P&4s #se the concept o( %:$ 7%i"t#al :o#ting

$o"wa"ding

With MPLS %P&4s; yo# can ha.e o.e"lapping p"i.ate

add"essing beca#se %:$4s ma)e them appea" as a

di((e"ent "o#ting table altogethe"-


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&ew MPLS %P& ,e"ms


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Close" loo) at the p"o.ide" netwo")

MPLS %P& %:$ C (i ti


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MPLS %P& > %:$ Con(ig#"ation

%:$ Con(ig#"ation tas)s* C"eate %:$

Assign :o#te !isting#ishe" to the %:$

Speci(y e6po"t and impo"t :o#te ,a"gets

Assign inte"(aces to %:$s

Configuration on PE

ip vrf Cust_aaa

rd 100:10 route-target export 100:10

route-target import 100:10

!

ip vrf Cust_bbb

rd 100:20

route-target export 100:20

route-target import 100:20

!

interface serial 0/0 ip vrf forwarding Cust_aaa

ip address 10001 22222

!

interface serial 0/1

ip vrf forwarding Cust_bbb

ip address 10001 22222

C"

#"

10100/2$

Cust_aaa

C"

10100/2$

Cust_bbb

%0/0

%0/1

vrf Cust_aaa

rd 100:10

vrf Cust_bbb

rd 100:20


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MPLS Applications

MPLS is al"eady #sed in many di((e"ent applications

nicast 5P "o#ting

M#lticast 5P "o#ting

MPLS ,/


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Plat(o"ms that s#ppo"t MPLS

,he Cisco Se"ies 2B1; 0; 0; 2D; D; 00+

&:P+1; 00+&:P+2S%; 00+&SP; Catalyst D000 with

:o#te Switch Mod#le 7:SM; 200; 01; 00; D00;

Catalyst D00?Cisco 00 Se"ies with WS+SP20+9 and

WS+SP20+9EL; =igabit Switch :o#te" 7=S:; :o#te

P"ocesso" Mod#le 7:PM; ni.e"sal 9"oadband :o#te"

79: 200; ASDD0; and 5=E800+:M all s#ppo"t

MPLS-


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,han) Fo#

Mpls Session

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