Advanced(Computer( Networks

Transcription

1 dvned(omputer( Networks MPLS ontents! MPLS((Multi(Protool(Lel(Swithing)! Lel(swpping! Elements(of(MPLS! Lel(swithing! Lel(distriution! Intertion(with(IGP! Trffi(engineering Prof.(ndrzej(Dud 2 MPLS Prolems(with(TM(integrtion! IGP(limits! very(lrge(routing(tles(in(the(ore(network! for(every(pket(look(up(more(tht(00(000(entries(! forwrding(from(the(isp(point(of(view(l just(find(the(egress( router! IP(routing(my(ignore(the(rel(physil(topology(! ISP(n(put((router(on(the(edge(nd(use(TM/Frme(Rely( Virtul(Pth,(swithes(in(the(middle! edge(router(selets(the(pth(sed(on(the(destintion(ddress(! route(look(up(done(only(one(in(the(isp(network(! ut(still(slility(prolems( IP#over#TM#VPs! TM(loud(invisile(to( Lyer( 3(Routing! Full(mesh(of(Vs(within( TM(loud(L n(nl)/2 IP#over#MPLS! TM(network(visile(to( Lyer( 3(Routing! Single(djeny(possile( with(edge(router MPLS(elimintes(the( nlsqured prolem(of(ip(over(tm(vps 3 4

2 MPLS! More(IGP(limits! SPF(lgorithms(send(trffi(on(shred(pth(nd(my(ignore( unloded(links! even(if(lod(lning(n(e(done(in(some(ses((igrp)! TM(or(FR(n(use(virtul(iruits,(ut(PPP/SDH/DWDM(does( not(! Gols(of(MPLS! inrese(forwrding(performne! provide(more(flexiility(thn(igp(routing! expliit(routing,(qos routing! kup(routes,(lod(lning,(vpn! multiprotool(l (unifying(view(t(2.5(lyer(l (unified(wy(of( ontrolling(the(underlying(lyer(2(network! TM,(FR,(PPP,(SDH/DWDM TM(VPI/VI(swithing TM(ells heder(ontins(vpi/vi 9 in VPI/VI out VPI/VI Lel(swpping MPLS(elements D Ingress(LER((Lel(Edge(Router) LSR((Lel(Swith(Router) Egress(LER((Lel(Edge(Router) V(tle(t(: in VPI/VI out VPI/VI Virtul(iruits(opened(in( the(following(order: H H H 2 H 3 H 4 2 D 7 sr dst out * 28.78/5 /70 8/ /6 /28 FE(L Lel(Mpping d FE in out xxx /70 /25 yyy /28 d/33 LSP((Lel(Swithed(Pth) 28.78/ /6 FE((Forwrd(Equivlene(lss) LI((Lel(Informtion(se) 8

3 MPLS(Priniples! Lels! ingress(ler(lssifies(pkets(to(identify(fe(tht(determines( (lel(inserts(the(lel((32(its)! LSR(swithes(sed(on(the(lel(! lel(swpping(l lel(hs(mening(lol(to(one(lsr( (requires(lel(distriution(protool)! egress(ler(removes(the(lel! LSR! ontins(li(l swithing(tle(tht(determines(the(pth(in( the(network((lsp)! LSP(L similr(to((tm/fr(virtul(iruit! hnge(of(the(forwrding(prdigm! insted(of(hop(y(hop! LSP(determined(t(entry(in(funtion(of(FE,(soure,(or(other 9 Forwrding(Equivlene(lsses! FE(L group(of(ip(pkets(! forwrded(in(the(sme(mnner,(over(the(sme(pth,(nd( with(the(sme(forwrding(tretment(! FE(my(orrespond(to(! destintion(ip(sunet! soure(nd(destintion(ip(sunet(! trffi(lss(tht(ler(onsiders(signifint(! For(exmple,(ll(trffi(with((ertin(vlue(of(IP( preedene(my(onstitute((fe! FE(in(our(exmples! IP(prefix 0 Forwrding(Equivlene(lsses MPLS(Enpsultion(L PPP(&(LN IP LER IP LSP L L LSR IP LSR Pkets#re#destined#for#different#ddress# prefixes,#ut#n#e mpped#to#ommon#pth L2 L2 IP L3 L3 LER IP Lyer#2#Heder (eg.#ppp,#802.3) Lel#Stk Entry#Formt MPLS# Shim Heders#(Sn) n 4#Otets Network#Lyer#Heder nd#pket#(eg.#ip) Lel Exp. S TTL Lel:## Lel#Vlue,#20#its Exp.:# Experimentl,#3#its#(ws#lss#of#Servie) S: ottom#of#stk,###it###(#=#lst#entry#in#lel#stk) TTL: Time#to#Live,#8#its! FE(=( (suset(of(pkets(tht(re(ll(treted(the(sme( wy(y((router! onventionl(routing:((pket(is(ssigned( to((fe(t( eh(hop((i.e.(l3(looklup),(in(mpls(it(is(only(done(one(! MPLS(on(PPP(links(nd(LNs(uses(shim(heder! inserted(etween(lyer(2(nd(3(heders t(the(network( ingress 2

4 MPLS(Enpsultion(L TM MPLS(exmple TM#Heder Formt TM SR TM#Heder TM##Pylod Option# Option#2 Option#3 n 5#Otets VPI VI PT LP HE Generi#Lel#Enp. (PPP/LN#formt) 48(ytes Lel 48(ytes ( ( Lel omined#lel TM#VPI#(Tunnel) Lel L#5#PDU#Frme#(nx48#ytes) Network#Lyer#Heder nd#pket#(eg.#ip) L5#Triler! Top((or(2(lels(re(ontined(in(the(VPI/VI(fields(of( TM(heder! one(in(eh(or(single(lel(in(omined(field,(negotited(y(ldp! Further(fields(in(stk(re(enoded(with( shim heder( sr dst out * 28.78/5 /70 * 29.88/6 /70 sr dst out * 29.88/6 /28 * 28.78/5 /28 8/ /6 / in(ppp/ln(formt 3 4 in d out /70 /25 d/28 /25 d/30 /33 in in out /25 /77 out /33 /37 FE(skipped(in(LI in out /77 pop /37 pop / /6 Lel(Distriution(Protool((LDP) Lel(distriution(ensures(tht(djent(routers(hve (ommon(view(of(fe(<d>(lel(indings Routing(Tle: ddrdprefix((((next(hop /8((((((LS IP(Pket Lel(Informtion(se: LelDIn(((((FE(((((LelDOut XX(((((((((( /8((((((7 Step#3:##LSR#inserts#lel vlue#into#forwrding#se Routing(Tle: ddrdprefix((((next(hop /8((((((LS LS LS LS For( /8 use(lel( 7 Step#2:##LSR#ommunites inding#to#djent#lsr Lel(Informtion(se: LelDIn(((((FE(((((LelDOut 7(((((((((( /8(((((((XX Step#:##LSR#retes#inding etween#fe#nd#lel#vlue ommon%understnding%of%whih%fe%the%lel%is%referring%to! Lel(distriution(n(either(piggyk(on(top(of(n(existing(routing(protool, or((dedited(lel(distriution(protool((ldp)(n(e(reted. 5 Lel(distriution! Lel(distriution(is(lwys(done(from(downstrem(to( upstrem! downstrem+unsoliited:( new(route(=>(send(new(lel LS((! downstrem+on+demnd:( upstrem(lsr(sks(for((lel LS LelLFE(inding Request(for(inding LelLFE(inding LS((( LS 6

5 Lel(retention Lel(ontrol LS((( LS((( LS Vlid(NextLHop LS(( Lierl LS Vlid(NextLHop LS onservtive! Lel(retention(n(e! lierl:( (memorize(ll(lels(from(downstrem(lsr((fster)! onservtive:( memorize(only(seleted(lels((less(memory)( X 7 Inoming Lel! Lel(ontrol(n(e Next(Hop (for(fe) Outgoing Lel! ordered:( (LSR(only(inds(nd(dvertise((lel(for(( prtiulr(fe(if! it(is(the(egress(lsr(for(tht(fe(or! it(hs(lredy(reeived((lel(inding(from(its(nextlhop! LSP(formtion( flows from(egress(to(ingress! independent:( LSR(inds((Lel(to((FE(independently,( whether(or(not(the(lsr(hs(reeived((lel(from(the(nextl hop(for(the(fe(! LSR(then(dvertises( the(lel(to(its(neighor! LSP(is(formed(s(inoming(nd(outgoing(lels(re(splied( together 8 Lel(distriution Lel(distriution(exmple(L OSPF! Different(lel(distriution(protools! LDP((Lel(Distriution(Protool)! defined(for(mpls! Extension( of(gp! Extension( of(rsvp! RSVPLTE:(trditionl(RSVP(+(Expliit(Route! RLLDP((onstrintLsed(LDP)! LDP(+(Expliit(Route,( (L IP(prefix M. (L IP(ddress,( (L interfe /LL/L3(L LI(entry M. O. N. M.2 T. P. N.2, M, N, O, M, T, N, P 9 20

6 OSPF(L routing(tles Lel(indings O: lol M: lol N: lol : O.2 : M.2 : N.2 T: M.2 P: N.2 M. O. N. N: lol P: lol : P.2 : N. : N. T: N. M: N. O: N. M.2 T. P. N.2 M: lol T: lol : T.2 : M. : M. N: M. P: M. O: M. 2 : /L0, /L02 : /L03, /L04 : /L05, /L06, -/pop M : /L07, /L08, -/pop N : /L09, /L0, -/pop O : /L, /L2, -/pop P : /L3, /L4 T : /L5, /L6 M. O. N. : /L7 : /L8, -/pop : /L9 M : /L20 N : /L2, -/pop O : /L22 P : /L23, -/pop T : /L24 M.2 T. N.2 P. : /L25, -/pop : /L26 : /L27 M : /L28, -/pop N : /L29 O : /L30 P : /L3 T : /L32, -/pop 22 Swithing(tles LDP(Protool( UDPLHello : /L0 : /L04 : -/pop M : -/pop N : -/pop O : -/pop P : /L4 T : /L5 /L7-/L0 /L9--/pop /L20--/pop /L22--/pop /L24-/L5 /L26-/L04 /L27--/pop /L29--/pop /L30--/pop /L3-/L4 M. O. N. : /L7 : -/pop : /L9 M : /L20 N : -/pop O : /L22 P : -/pop T : /L24 M.2 T. N.2 /L04--/pop /L4--/pop P. : -/pop : /L26 : /L27 M : -/pop N : /L29 O : /L30 P : /L3 T : -/pop /L0--/pop /L5--/pop 23 UDPLHello TPLopen Initiliztion(s) Lel(request(for((FE Lel(inding:(FE(L Lel 24

7 ERLLSP(setup(using(RLLDP Trffi(Engineering(with(MPLS. Lel Request messge. It ontins ER pth <,,D> 2. Request messge proessed nd next node determined. Pth list modified to <,D> 3. Request messge termintes. Demnd 6. When LER reeives lel mpping, the ER estlished. 5. LSR reeives lel to use for sending dt to LER D. Lel tle updted 4. Lel mpping messge origintes. D Trffi#engineering#is#the#proess#of#mpping#trffi#demnd#onto##network LER# LSR# LSR# LER#D Network Topology Ingress! Expliit(Route(setup ER Lel Swithed Pth! RLLDP(n(lso(e(used(to(reserve( resoures! pek(rte,(ommitted(rte,(urst(size Egress 25! Mximize( utiliztion(of(links(nd(nodes(! Engineer(links(to(hieve(required(dely! Spred(the(network( trffi(ross(network(links,(minimize( impt(of(single(filure! Ensure(ville(spre(link(pity(for(reLrouting(trffi 26 Unifying(forwrding(prdigm GMPLS/MPλS( Optil#Lel#Swith Ethernet PPP (SONET,#SDH) TM Frme Rely λ Routing# ontrol! MPLS(offers(n(endLtoLend(unifying(forwrding(prdigm! MPLS(is( multiprotool elow((link(lyer)(s(well(s(ove( (network(lyer)! provides(for(onsistent(opertions,(engineering(ross(multiple( tehnologies! llows(opertors(to(ontrol(different(tehnologies(in((unified( mnner λ λ 2 λ n λ λ 2 λ n Fri λ λ 2 λ λ 2 λ n λ λ 2 λ n! Optil(networks(suh(s(DWDM! λ is(just(nother(lel(to(distriute(l no(new(protools(required 27 28

8 Fts(to(rememer! MPLS(llows(flexile(pket(lssifition(nd( network(resoures(optimiztion! Lels(re(distriuted(y(different(protools! LDP,(RSVP,(GP! Lels(hve( lol((lsr)(signifine! no(need(for(glol((domin)(wide(lel( llotion/numering! Different(link(lyer(protools(my(oLexist(in(the( sme(lsr 29