01-04-2012 06:14 AM - edited 03-07-2019 04:10 AM
I would like to implement a track command without HSRP .
like "trace 111 interface se0/0 ip route"
if interface se0/0 interface goes down and i want to divert the tracffice to Gi0/1..
Plese help me ...
Thanks
Sri
01-04-2012 06:42 AM
You can use, IP-SLA to check the route-availability and based on return reply, you can re-route the traffic to another interface. It is much similar to default-route failover.
Thanks
Rizwan Rafeek
I lover Sri Lanka.
01-04-2012 10:31 PM
Hi ,
Can I use below configuration ?
track 1 interface se0/0
delay down 5
exit
ip route 1.1.1.0 255.255.255.0 se0/0 track 1
If the se0/0 goes down the static route will be vanished from routing table. so that traffice will be diverted to ohter interface depending on metric.
thanks
sri
01-04-2012 11:25 PM
Hi Sri,
I did lab this up this GNS3 and seems ur idea is working.
Track:
Router3(config)#track 1 interface fa0/0 line-protocol
Static Route:
Router3#sh run | i 11.0.0.0 255.0.0.0
ip route 11.0.0.0 255.0.0.0 FastEthernet0/0 track 1
Router3#traceroute 11.11.11.11
Type escape sequence to abort.
Tracing the route to 11.11.11.11
1 2.2.2.1 36 msec 16 msec 20 msec
2 1.1.1.1 48 msec * 48 msec
Router3(config-if)#int fa0/0
Router3(config-if)#sh
Router3(config-if)#
*Mar 1 00:44:54.139: %TRACKING-5-STATE: 1 interface Fa0/0 line-protocol Up->Down
Router3(config-if)#^Z
Router3#
*Mar 1 00:44:55.227: %SYS-5-CONFIG_I: Configured from console by console
*Mar 1 00:44:56.139: %LINK-5-CHANGED: Interface FastEthernet0/0, changed state to administratively down
Router3#
*Mar 1 00:44:57.139: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to down
Router3#traceroute 11.11.11.11
Type escape sequence to abort.
Tracing the route to 11.11.11.11
1 3.3.3.2 44 msec * 24 msec
Now the Route is using the route learnt via EIGRP instead of the static.
Krishna
01-04-2012 11:54 PM
Hi John,
Hope the below explaination will help you...
R1(config)# ip route 0.0.0.0 0.0.0.0 2.2.2.2
R1(config)# ip route 0.0.0.0 0.0.0.0 3.3.3.3 10
If you notice the Administrative Distance for the secondary route pointing to ISP2 is increased to 10 so that it becomes the backup link.
The above configuration with just two floating static routes partially accomplishes our requirement as it will work only in the scenario where the routers interfaces connected to the WAN link are in up/down or down/down status. But in a lot of situations we see that even though the links remain up but we are not able to reach the gateway, this usually happens when the issue is at the ISP side.
In such scenarios, IP SLAs becomes an engineer's best friend. With around six additional IOS commands we can have a more reliable automatic failover environment.
Using IP SLA the Cisco IOS gets the ability to use Internet Control Message Protocol (ICMP) pings to identify when a WAN link goes down at the remote end and hence allows the initiation of a backup connection from an alternative port. The Reliable Static Routing Backup using Object Tracking feature can ensure reliable backup in the case of several catastrophic events, such as Internet circuit failure or peer device failure.
IP SLA is configured to ping a target, such as a publicly routable IP address or a target inside the corporate network or your next-hop IP on the ISP's router. The pings are routed from the primary interface only. Following a sample configuration of IP SLA to generate icmp ping targeted at the ISP1s next-hop IP.
R1(config)# ip sla 1
R1(config)# icmp-echo 2.2.2.2 source-interface FastEthernet0/0
R1(config)# timeout 1000
R1(config)# threshold 2
R1(config)# frequency 3
R1(config)# ip sla schedule 1 life forever start-time now
The above configuration defines and starts an IP SLA probe.
The ICMP Echo probe sends an ICMP Echo packet to next-hop IP 2.2.2.2 every 3 seconds, as defined by the “frequency” parameter.
Timeout sets the amount of time (in milliseconds) for which the Cisco IOS IP SLAs operation waits for a response from its request packet.
Threshold sets the rising threshold that generates a reaction event and stores history information for the Cisco IOS IP SLAs operation.
After defining the IP SLA operation our next step is to define an object that tracks the SLA probe. This can be accomplished by using the IOS Track Object as shown below:
R1(config)# track 1 ip sla 1 reachability
The above command will track the state of the IP SLA operation. If there are no ping responses from the next-hop IP the track will go down and it will come up when the ip sla operation starts receiving ping response.
To verify the track status use the use the “show track” command as shown below:
R1# show track
Track 1
IP SLA 1 reachability
Reachability is Down
1 change, last change 00:03:19
Latest operation return code: Unknown
The above output shows that the track status is down. Every IP SLAs operation maintains an operation return-code value. This return code is interpreted by the tracking process. The return code may return OK, OverThreshold, and several other return codes.
Different operations may have different return-code values, so only values common to all operation types are used. The below table shows the track states as per the IP SLA return code.
Tracking | Return Code | Track State |
Reachability | OK or over threshold (all other return codes) | Up Down |
The Last step in the IP SLA Reliable Static Route configuration is to add the “track” statement to the default routes pointing to the ISP routers as shown below:
R1(config)# ip route 0.0.0.0 0.0.0.0 2.2.2.2 track 1
R1(config)# ip route 0.0.0.0 0.0.0.0 3.3.3.3 10
The track number keyword and argument combination specifies that the static route will be installed only if the state of the configured track object is up. Hence if the track status is down the secondary route will be used to forward all the traffic.
Please rate the helpfull posts.
Regards,
Naidu.
01-05-2012 12:27 AM
Wow great explanation Naidu!!!
Can you please give a little more clarity on:
R1(config)#threshold 2
What is this for?
Krishna
01-05-2012 01:34 AM
Hi Krishna,
The threshold in milliseconds is a optional command, it Sets the upper threshold value for calculating network monitoring statistics created by an IP SLAs operation.
Would required you to go through the below link for more information.
http://www.cisco.com/en/US/docs/ios/12_4/ip_sla/configuration/guide/hsthresh.html
Please rate all the helpfull posts.
Regards,
Naidu.
01-05-2012 03:04 AM
Hi,
If your primary interface is a serial interface then you dont need any track or IP SLA at all. You can achieve failover just by using floating static routes. Because router will automatically make the required changes in the routing table as soon as your serial interface protocol goes down.
Regards,
Pawan Sharma
01-09-2012 03:43 AM
Hi Srikanth,
What is the status on this post?
Hope you have all suitable responses / solutions for your primary post.
Hence please remember to rate all the helpfull posts which encourage other throughout this great CSC program.
Please rate all the helpfull posts.
Regards,
Naidu.
01-09-2012 07:13 AM
Hi Naidu,
Thanks for your detailed information on IPSLA.
We are planning to run EIGRP on P2P link.
Thanks
- Sri
01-09-2012 10:58 PM
Hi Srikanth,
The primary post you are planning to track the interface without HSRP and for which the suitable solutions has given.
And now you are saying that you are planning to implement HSRP which means you are keep on changing the primary thred and making people confuse what you need exactly.
Remember that the contributors and experts putting the efforts and spending their time to give you the proper solutions based on the thred you opened.
Open always the initial thred or post or query with a proper plan and keep in mind to what you are looking to achieve. Also value the experts time and efforts.
This CSC is a great forum which can solve your problems as you are expecting. So value the people in this forum.
Please rate all the helpfull posts.
Regards,
Naidu.
01-10-2012 12:36 AM
Naidu,
We had a plan to implement track command but after looking into our complete architecture of the network then we planned to change our mind to implent EIGRP on our netowrk since we have other backup link.
I alway repect all thread here ,since you all give very useful suggestions here.
Thanks
Sri
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