From: Duncan Maccubbin (duncan.maccubbin@earthlink.net)
Date: Tue Jul 11 2006 - 09:15:45 ART
Kay,
You won't actually be tracking a link failure but the next hop IP. So if your interface goes down the IP goes down. SLA will fail the ping test and use the next IP in your route-map. Here is Cisco's example:
In the following example, object tracking is configured for PBR.
The policy is that packets received on Ethernet 0, should be forwarded to 10.1.1.1 only if that device is reachable (responding to pings). If 10.1.1.1 is not up, then the packets should be forwarded to 10.2.2.2. If 10.2.2.2 is also not reachable, then the policy routing fails and the packets are routed according to the routing table.
Two SAA Echo operations are configured to ping the remote devices. The SAA operations are then tracked. Policy routing will monitor the state of the tracked operations and make forwarding decisions based on their state.
! define and start the SAA operations
rtr 1
type echo protocol ipicmpecho 10.1.1.1
rtr schedule 1 start-time now life forever
!
rtr 2
type echo protocol ipicmpecho 10.2.2.2
rtr schedule 2 start-time now life forever
!
!track the SAA operations
track 123 rtr 1 reachability
track 124 rtr 2 reachability
!
! enable policy routing on the incoming interface
interface ethernet 0
ip address 10.4.4.4 255.255.255.0
ip policy route-map alpha
!
! 10.1.1.1 is via this interface
interface ethernet 1
ip address 10.1.1.254 255.255.255.0
!
! 10.2.2.2 is via this interface
interface ethernet 2
ip address 10.2.2.254 255.255.255.0
!
! define a route-map to set the next-hop depending on the state of the tracked rtrs
route-map alpha
set ip next-hop verify-availability 10.1.1.1 10 track 123
set ip next-hop verify-availability 10.2.2.2 20 track 124
-----Original Message-----
>From: Kay D <krsna83@gmail.com>
>Sent: Jul 11, 2006 8:04 AM
>To: Duncan Maccubbin <duncan.maccubbin@earthlink.net>
>Cc: ccielab@groupstudy.com
>Subject: Re: SAA RTR reaction
>
>Thanks Duncan , but how would i match a link failure , i will have to make
>this completely automated , such that until and unless there is a link
>failure the traffic should not be policy routed .
>
>Is there a way of linking RTR and PBR ,which would hopefully fix it
>
>TIA
>Kay
>
>
>On 7/11/06, Duncan Maccubbin <duncan.maccubbin@earthlink.net> wrote:
>>
>> Kay,
>>
>> I would say if you want to do something like that you'll need to use a PBR
>> for your primary connection and then fail to another next hop if that fails.
>>
>>
>> http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124cg/hirp_c/ch20/h_pbrtrk.htm
>>
>>
>>
>> -----Original Message-----
>> >From: nobody@groupstudy.com <nobody@groupstudy.com>
>> >To: Cisco certification <ccielab@groupstudy.com>
>> >Sent: Tue Jul 11 05:12:44 2006
>> >Subject: SAA RTR reaction
>> >
>> > Hi ,
>> > I am trying to detect an indirect link failure on a network
>> between
>> >routers and pix firewalls ,without using Routing protocols using RTR by
>> >sending echos , now if RTR detects a link failure can it invoke
>> ,,,,,,,for
>> >example ,,,,,,,a Route-map ,,,,,using which i can redirect the traffic to
>> >another interface instead of black holing the traffic (some kind of a
>> >policy based routing using static routes would also do ) .
>> >
>> >If yes , please let me know how .
>> >
>> >TIA
>> > Kay
>> >
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