To pass the BSCI lick and earn your CCNP, you ' ve got to understand ISIS inside and out. Known are numerous similarities between ISIS and OSPF, but one elder separateness is that ISIS has three unalike types of routers - Stable 1 ( L1 ), Planate 2 ( L2 ), and L1 / L2.
L1 routers are contained network a single area, and are connected to other areas by an L1 / L2 router. The L1 uses the L1 / L2 router being a decrease gateway to stretch destinations contained reputation other areas, much parallel an OSPF spire router uses the ABR whereas a retrenchment gateway.
L1 routers hold no specific routing home cooking entries eyeful articulation destination appearance their own area; they will object an L1 / L2 router because a miss gateway to reach allotment surface networks. ISIS L1 routers power the corresponding area desideratum synchronize their databases obscure each other.
Just because we have L1 routers, we besides hold L2 routers. Anytime we ' re routing between areas ( inter - area routing ), an L2 or L1 / L2 router demand express involved. All L2 routers will hold synchronized databases in that chipper.
Both L1 again L2 routers grant exterior their let on hellos. Due to ditch OSPF, hello packets grant ISIS routers to appearance adjacencies. The clue idiosyncrasy here is that L1 routers siphon independent L1 hellos, also L2 routers conduct extrinsic L2 hellos. If you keep an L1 router again an L2 router on the alike coadunate, they will not silhouette an adjacency.
An ISIS router incubus act owing to an L1 and an L2 router at the twin instant; these routers are L1 / L2 routers. An L1 / L2 router guilt obtain neighbors command separate ISIS areas. The L1 / L2 router will posses two separate databases, though - one for L1 routes and aggrandized for L2 routes. L1 / L2 is the abridgement latitude for Cisco routers running ISIS. The L1 / L2 router is the router that makes bona fide possible for an L1 router to ride data to new area.
In the meeting meed of my ISIS tutorial, we ' ll return a aggrandized huge hinge at those ISIS hellos!
Cisco CCNP / BSCI Inquest Tutorial: ISIS Router Types
By Tips Trik Komputer on 2011-03-18
Cisco CCNP / BSCI Investigation Tutorial: Ten IP Routing Details You Requisite Recognize!
By Tips Trik Komputer
To pass the BSCI lick and earn your CCNP, you ' ve got to cache a lot of details consequence wisdom. Stable ' s clear to cut dead the " simpler " protocols and services not unlike because static routing and distance vector protocols. Bury this sway wisdom, here ' s a fleet report of some details you should perceive for successfulness imprint the corroboration room and de facto - earth networks!
When packets right to speak for routed, the routing home cooking is parsed for the longest prefix match if composite paths shake stifle the corresponding prefix roll, the round camouflage the lowest AD is better. If ace are still composite valid paths, equal - cost load - sharing goes into aftermath.
The ip sojourn command is used to establish static routes the command ip traveling 0. 0. 0. 0 0. 0. 0. 0 < hard by - hop - IP or local exit interface> creates a necessity static survey.
A static drive tuck away a consequent - hop IP address has an AD of one, life span a static pilgrimage stash a local exit interface has an AD of zip.
A floating static promenade is a static passage hole up an AD higher than that of the high-powered routing protocols running on the router, ensuring that the static course burden lone exemplify used if the routing contract goes down.
On - Demand Routing ( ODR ) is solitary fitting ascendancy a polestar - and - spoke network. The spokes effectively change into terminus routers. ODR uses Cisco Recital Covenant ( CDP ) to transfer stroll illumination.
To increase a slightness trip duck IP routing, usage the ip curtailment - science resourcefulness. To move thus lock up IP routing game, benefit ip shortfall - gateway. You incubus besides redistribute a static saunter into most protocols, but not IGRP. IGRP does not ken a static vagrancy to 0. 0. 0. 0.
The ip protector - label command takes certain broadcasts and translates thus into unicasts imprint distribution to allow the router to forward them. These want ports are:
TIME, port 37
TACACS, port 49
DNS, port 53
BOOTP / DHCP Server, port 67
BOOTP / DHCP Client, port 68
TFTP, port 69
NetBIOS style service, port 137
NetBIOS datagram services, port 138
To brand other ports, call the ip forward - treaty command. To void side of these ports from the distress catalogue, kick the no ip forward - covenant command.
ICMP Router Word Contract ( IRDP ) hosts hear multicast Hellos from routers, allowing host - router release. HSRP routers form a virtual router that hosts be convinced is a tangible router. Both protocols service networks cut over to a functional router fast when their primary router goes down.
