CCIE實(shí)驗(yàn)室考試指南(2)

Lab 02 -
    Policy Routing
    The following scenario refers to the diagram below.
    Scenario:
    All routers are configured in a single OSPF area.
    Router_C, based on the cost metric for OSPF will send all packets with
    a destination network address of 10.4.0.0 out the E0 interface.
    Problem:
    Have all packets destined for network 10.4.0.0 exit the Serial 0
    Router_C.
    Router_C#sh ip route
    Codes: C - connected, S - static,
    I - IGRP,
    R - RIP, M - mobile, B - BGP,
    D - EIGRP,
    EX - EIGRP external, O - OSPF,
    IA - OSPF inter area,
    N1 - OSPF NSSA external type 1,
    N2 - OSPF NSSA external type 2,
    E1 - OSPF external type 1,
    E2 - OSPF external type 2, E - EGP,
    i - IS-IS,
    L1 - IS-IS level-1,
    L2 - IS-IS level-2,
    * - candidate default,
    U - per-user static route,
    o - ODR
    Gateway of last resort is not set
    10.0.0.0/16 is subnetted, 3 subnets
    C 10.2.0.0 is directly connected,
    Serial0
    C 10.3.0.0 is directly connected,
    Ethernet0
    O 10.4.0.0 [110/74] via 10.3.0.1,
    00:00:13, Ethernet0 　Solution:
    Policy routing will allow you to configure a route map. The route map
    will be used by the router in lieu of destination routing.
    In this scenario the best route to the destination network 10.4.0.0 is
    to go ethernet. We want to force the route to take the serial
    connection.
    Step 1
    Configure a route map tag. I chose "takeserial".
    Step 2
    Point the route map to the tag. Don’t let the 10 shake you it is just a
    sequence number.
    Router_C(config)#route-map
    takeserial permit ?
    <0-65535>
    Sequence to insert to/delete
    from existing route-map entry
    Step 3
    Identify which packet should be route mapped. In our example we will
    match the ip address of access list 1.
    Step 4
    Tell the router where to send the matched packet. We will send the
    packets to Serial 0.
    Current configuration:
    !
    version 11.2
    !
    hostname Router_C
    !
    !
    !
    interface Ethernet0
    ip address 10.3.0.3 255.255.0.0
    !
    interface Ethernet1
    ip address 10.1.0.3 255.255.0.0
    ip policy route-map takeserial*Step 1
    !
    interface Serial0
    ip address 10.2.0.1 255.255.0.0
    clockrate 38400
    !
    interface Serial1
    no ip address
    shutdown
    !
    router ospf 100
    network 10.0.0.0 0.255.255.255 area 0
    !
    no ip classless
    access-list 1 permit 10.1.0.5
    route-map takeserial permit 10 *Step 2
    match ip address 1 *Step 3
    set interface Serial0 *Step 4
    !
    line con 0
    line aux 0
    line vty 0 4
    login
    !
    end
    Now we will ping 10.4.0.2 from Workstaton A:
    Router_C#debug ip policy
    Policy routing debugging is on
    Router_C#
    IP: s=10.1.0.5 (Ethernet1), d=10.4.0.2,
    len 74, policy match
    IP: route map takeserial, item 10,
    permit
    IP: s=10.1.0.5 (Ethernet1),
    d=10.4.0.2 (Serial0),
    len 74, policy routed
    IP: Ethernet1 to Serial0 10.4.0.2
    IP: s=10.1.0.5 (Ethernet1), d=10.4.0.2,
    len 74, policy match
    IP: route map takeserial, item 10,
    permit
    IP: s=10.1.0.5 (Ethernet1),
    d=10.4.0.2 (Serial0),
    len 74, policy routed
    IP: Ethernet1 to Serial0 10.4.0.2
    IP: s=10.1.0.5 (Ethernet1), d=10.4.0.2,
    len 74, policy match
    IP: route map takeserial, item 10,
    permit
    IP: s=10.1.0.5 (Ethernet1),
    d=10.4.0.2 (Serial0),
    len 74, policy routed
    IP: Ethernet1 to Serial0 10.4.0.2
    IP: s=10.1.0.5 (Ethernet1), d=10.4.0.2,
    len 74, policy match
    IP: route map takeserial, item 10,
    permit
    IP: s=10.1.0.5 (Ethernet1),
    d=10.4.0.2 (Serial0),
    len 74, policy routed
    IP: Ethernet1 to Serial0 10.4.0.2