Chapter 4 2/9/2016  CCNA 2 Chapter 4 - Routers Routers: - Route outerrs are are Compu omputters ers It has has a CPU CPU,, OS (Rou (Router ters s use Cisc Cisco o IOS) IOS),, Memor Memory y & Stora Storage ge (RAM/ROM/NRAM/!"AS#/#$) Importa%t a'e a'e - Router Compo%e%ts (o Memory) RAM oatie - Ru%%i%g IOS Ru%%i%g Co%ig !ie IP Routi%g &  ARP a'e a'e Pac*et +u +uer   ROM No%-oatie NRAM No%-oatie +oo*up I%structio%s +asic $i $iag%ostic Sotare "imite IOS - Startup Co%ig !ies IO IOS Other Sy System !ie !"AS# No%-oatie Routers use speciai.e ports a% %etor* i%terace cars to i%terco%%ect to other %etor*s - Rout Router ers s co% co%%e %ect ct mut mutip ipe e %et %etor or*s *s Router Routers s ha0e mut mutip ipe e i%ter i%terace aces, s, each each o% a ier iere%t e%t IP IP %eto %etor* r* 1 Routers Choose Best Paths Routers use static routes a% y%amic routi%g protocos to ear% a'out remote %etor*s a% 'ui their routi%g ta'es Routers use routi%g ta'es to etermi%e the 'est path to se% pac*ets Routers e%capsuates the pac*et a% orars it to the i%terace i%icate i% the routi%g ta'e 1 Packet Forwarding Methods Process Switching A% oer pac*et orari%g mecha%ism sti a0aia'e or Cisco router Fast Switching A commo% pac*et orari%g mecha%ism hich uses a ast-sitchi%g cache to store %e2t-hop i%ormatio% Cisco Epress Forwarding !CEF" he most rece%t, astest, a% preerre Cisco IOS pac*et-orari%g mecha%ism a'e e%tries are %ot pac*et-triggere i*e ast sitchi%g 'ut cha%ge-triggere 1 #e$au%t &atewa's o e%a'e %etor* access e0ices must 'e co%igure ith the ooi%g IP aress i%ormatio%3 IP Aress Ie%tiies u%i4ue host o% oca %etor* Su'%et Mas* Ie%tiies the host5s %etor* su'%et $eaut 6ateay "$R 7#o to get out o the %etor*8 1 Ena(%e )P on a *ost - - 1 Statica%%' Assigned )P Address Ma%uay assig%e IP Use to ie%tiy speciic %etor* resources such as ser0ers/pri%ters Ca% 'e use i% sma %etor*s ith itte amou%t o hosts #'na+ica%%' Assigned )P Address Automaticay o'tai%e IP aress !rom $#CP Ser0er Most hosts ac4uire their IP aress i%ormatio% through $#CP #e,ice E#s - "ights o% the 'ac* o the router pro0ie i%ormatio% i %eee 1 Conso%e Access - Co%soe Access re4uires9 A computer ith proper sotare (see thir item3 termi%a emu) - Co%soe Ca'e (R:-;< to $+= Co%soe Ca'e) ermi%a >muatio% Sotare3 eraerm/ Pu?/ #yperermi%a 1 Ena(%ing )P on a Switch I%rastructure e0ices re4uire IP aresses Ma%ageme%t IP aresses is assig%e o% a 0irtua i%terace 1 Con$igure Basic Router Settings Name the $e0ice $isti%guish the router5s %ame rom other routers Secure Ma%ageme%t Access Secure pri0iege e2ec, user e2ec, te%et access, a% e%crypte passors 1 Con$igure )P,4 Router )nter$ace o Co%igure3 - Co%igure ith a% IP & Su'%et Aress Must use @%o shuto%5 Seria Ca'e usi%g @$C>5 must ha0e a coc* rate Pro0ie a escriptio% 1 Con$igure )P,. Router )nter$ace o Co%igure3 Use IP0 aress (i%* oca / eui-;) Acti0ate usi%g @%o sh5 IP0 supports more tha% o%e aress Co%igure a speciie go'a u%icast aress (ar/e%gth) Co%igure a go'a IP0 Aress ith a% I%terace I$ i% the o orer ; 'its Co%igure a i%*-oca aress 1 Con$igure a oop(ack Address A oop'ac* i%terace is a ogica i%terace that is i%ter%a to the router It is %ot assig%e to a physica port, it is co%siere a sotare i%terace A oop'ac* i%terace is use or testi%g It is importa%t i% the OSP! routi%g process 1 /eri$' )nter$ace Settings Sho comma%s are use to 0eriy operatio% a% co%iguratio% o i%terace3 sho ip i%t 'rie  sho ip route - sho ru%%i%g-co%ig sho i%terace 9 sho ip i%teraces - ?ou ca% iter sho comma%s Use the @termi%a e%gth B%um'er15 comma% to speciy the %um'er o i%es to 'e ispaye o iter out speciic output o comma%s, use the 78 pipe character Ca% use parameters to iter3 sectio%, i%cue, e2cue, a% 'egi% 1 Best Path +est path is seecte 'y a routi%g protoco 'ase o% the 0aue or metric it uses to etermi%e the ista%ce o a %etor* A metric is the 0aue use to measure the ista%ce to a gi0e% %etor* +est path to a %etor* is the path ith the oest %etor* $y%amic routi%g protocos use their o% rues a% metrics to 'ui a% upate ta'es3 Routi%g I%ormatio% Protoco (RIP) - #op Cou%t Ope% Shortest Path !irst (OSP!) - Cost-'ase o% cumuati0e 'a%ith rom source to esti%atio% >%ha%ce I%terior 6ateay Routi%g Protoco (>I6RP) +a%ith, eay, oa, reia'iity 1 oad Ba%ancing Dhe% a router has to or more paths to a esti%atio% ith e4ua cost metrics, the% the router orars the pac*ets usi%g 'oth paths e4uay3 >4ua cost oa 'aa%ci%g ca% impro0e %etor* perorma%ce >4ua cost oa 'aa%ci%g ca% 'e co%igure to use 'oth  y%amic routi%g protoco a% static routes 1 Ad+inistrati,e #istance I mutipe paths to a esti%atio% are co%igure o% a router, the path i%stae i% the routi%g ta'e is the o%e ith the oest  Ami%istrati0e $ista%ce (A$) A static route ith a% A$ o E is more reia'e tha% a% >I6RP isco0ere route ith a% A$ o =F A irecty co%%ecte route ith a% A$ o F is more reia'e tha% a static route ith a% A$ o E $iagram3 - 1 1 Routing 0a(%e Sources show ip route $ispay the co%te%ts o the routi%g ta'e %oca% route inter$aces Ae to the routi%g ta'e he% a% i%terace is co%igure direct%' connected inter$aces Ae to the routi%g ta'e he% a% i%t is co%igure a% acti0e static routes Ae he% a route is ma%uay co%igure a% the e2it i%terace is acti0e d'na+ic routing protoco% Ae he% >I6RP or OSP! are impeme%te %etor*s are ie%tiie Static Routes - Static routes a% eaut static routes ca% 'e impeme%te ater irecty co%%ecte i%teraces are ae to the routi%g ta'e 1 #'na+ic Routing - Dhere the routers 7o the or* or us8 $y%amic routi%g is use 'y routers to share i%ormatio% a'out the reacha'iity a% status o remote %etor*s It perorms %etor* isco0ery a% mai%tai%s routi%g ta'es >I6RP - OSP! - IS-IS - etc