RTR tracking without IP SLA feature

Answered Question
May 26th, 2010

Hi

We are using the following image on our production  layer-3 switch

IOS (tm) s72033_rp Software (s72033_rp-IPSERVICESK9_WAN-M), Version 12.2(18)SXF11, RELEASE  SOFTWARE (fc1)

There is no support for IP SLA in the current  version. But it seems there is no support for "track 2 rtr 10 reachability" and "ip route x y z track 1"  type of commands either. While the following commands are accepted

# rtr 10

          # type echo protocol ipIcmpEcho  10.10.10.10

          # frequency 2

          # request-data-size 32

          # timeout 1000

# rtr schedule 10 life forever start-time now

How to make the following work on the current IOS.  Is there an alternative to achieve the same or is IOS upgrade a must???

# track 2 rtr 10 reachability

# track 1 list boolean and

          # object 2 not

ip route 11.11.11.0 255.255.255.0 12.12.12.12 track  1

P.S. The objective is to install a static route for  network 11.11.11.0/24 towards  12.12.12.12 when the device at 10.10.10.10 (not directly connected) is NOT reachable. This will be backup route for the remote 10 network. We don't have dynamic routing or vpn in between. Any ideas??

Thanks.

I have this problem too.
0 votes
Correct Answer by Calin Chiorean about 6 years 6 months ago

Hi there!

I don't know if this is working 100% (and that your image support EEM) but look below.

I understand that you can type this:

# rtr 10

          # type echo protocol ipIcmpEcho  10.10.10.10

          # frequency 2

          # request-data-size 32

          # timeout 1000

          # threshold 100

# rtr schedule 10 life forever start-time now

EEM is used and you have a timeout occurence (10.10.10.10 is not reachable anymore):

event manager applet RTR_10_TIMEOUT
event snmp oid 1.3.6.1.4.1.9.9.42.1.2.9.1.6.10 get-type exact entry-op eq entry-val 1 exit-op eq exit-val 2 poll-interval 5
action 1.0 syslog msg "10.10.10.10 not reachable"

action 1.1 cli command "enable"

action 1.2 cli command "configure terminal"

action 1.3 cli command "ip route 11.11.11.0 255.255.255.0 12.12.12.12"

Explanation for OID value can be found here:

http://tools.cisco.com/Support/SNMP/do/BrowseOID.do?local=en&translate=Translate&objectInput=rttMonCtrlOperTimeoutOccurred

The last .10 in the OID value is your RTR (or IP SLA) number.

Of course the problem is that route remains there even if 10.10.10.10 is reachable again. To remove it you need another EEM.

This example can be "fine tuned" to match your expectation.

Let me know if this helps you.

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Correct Answer
Calin Chiorean Thu, 05/27/2010 - 01:30

Hi there!

I don't know if this is working 100% (and that your image support EEM) but look below.

I understand that you can type this:

# rtr 10

          # type echo protocol ipIcmpEcho  10.10.10.10

          # frequency 2

          # request-data-size 32

          # timeout 1000

          # threshold 100

# rtr schedule 10 life forever start-time now

EEM is used and you have a timeout occurence (10.10.10.10 is not reachable anymore):

event manager applet RTR_10_TIMEOUT
event snmp oid 1.3.6.1.4.1.9.9.42.1.2.9.1.6.10 get-type exact entry-op eq entry-val 1 exit-op eq exit-val 2 poll-interval 5
action 1.0 syslog msg "10.10.10.10 not reachable"

action 1.1 cli command "enable"

action 1.2 cli command "configure terminal"

action 1.3 cli command "ip route 11.11.11.0 255.255.255.0 12.12.12.12"

Explanation for OID value can be found here:

http://tools.cisco.com/Support/SNMP/do/BrowseOID.do?local=en&translate=Translate&objectInput=rttMonCtrlOperTimeoutOccurred

The last .10 in the OID value is your RTR (or IP SLA) number.

Of course the problem is that route remains there even if 10.10.10.10 is reachable again. To remove it you need another EEM.

This example can be "fine tuned" to match your expectation.

Let me know if this helps you.

Calin Chiorean Thu, 05/27/2010 - 01:36

I think this will not work for you as according to the software advisory in Cisco EEM is supported from IOS versions SXI and SXH above. Anyway...try.

seabird505 Thu, 05/27/2010 - 23:39

Yes EEM is supported. Thanks so much for guidling me towards implementing it via EEM and generously providing me with the script for it.

For the reference of others who may need to acheive the same without IP SLA, the config is like this


rtr 10
  type echo protocol ipIcmpEcho 10.10.10.10
  timeout 1000
  frequency 3
  request-data-size 32
rtr schedule 10 life forever start-time now
!
event manager applet EEM_PRIMARY_DOWN
  event snmp oid 1.3.6.1.4.1.9.9.42.1.2.9.1.6.10 get-type exact entry-op eq entry-val 1 exit-op eq exit-val 2 poll-interval 3
  action 1.0 syslog msg "Primary link DOWN - Failing over to backup link"
  action 1.1 cli command "enable"
  action 1.2 cli command "configure terminal"
  action 1.3 cli command "ip route 11.11.11.0 255.255.255.0 12.12.12.12"
!
event manager applet EEM_PRIMARY_UP
  event snmp oid 1.3.6.1.4.1.9.9.42.1.2.9.1.6.10 get-type exact entry-op eq entry-val 2 exit-op eq exit-val 1 poll-interval 3
  action 1.0 syslog msg "Primary link UP - Failing over to primary link"
  action 1.1 cli command "enable"
  action 1.2 cli command "configure terminal"
  action 1.3 cli command "no ip route 11.11.11.0 255.255.255.0 12.12.12.12"

!

Thanks again Calin !

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