IP SLA and HSRP - Please help

Hello I would like to achieve redundancy but I was not able to understend completely the topic:

I read this:

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My scenario is:

Router A: SHDSL - int atm0/0.1 public wan ip fast0 - (lan side)

Router B: ADSL - int atm0/0.1 public wan ip fast0 - (lan side)

The routers are identical, are two Cisco 2650 with 32F/128D and IOS

12.4(17a) ADVSEC

I have managed creating the virtual ip of HSRP

my troubles are in the IP SLA command.

I need that router A pings this IP (example) I need that router B pings this IP (example)

The pinged IP is to test the reachability of the upstream router of each connection.

I would like to ping it every 30 seconds (frequency 30) and after 3 (three) pings un-answered, the router will change connection from sHDSL to ADSL. After 3 pings answered, the connection is re-routed on the main SHDSL link.

Can someone help me?

Reply to
Elia Spadoni
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You can configure tracking in many different ways. Personally assuming your SDSL is primary and ADSL is backup, configure HSRP on the LAN side and then on your primary router track the object as part of HSRP.... somthing like:


ip sla monitor 1 type echo protocol ipIcmpEcho frequency X ip sla monitor schedule 1 life forever start-time now ! track 1 rtr 1 reachability ! int Ethernet 0/0 ip address standby 10 ip X.X.X.X standby 10 track 1 standby 10 track ATM0/0 standby 10 priority 105 standby 10 preempt etc.....

This way if your tracked object of 1, a ping to fails, the HSRP of this router will be reduced and your secondary ADSL router take over.

Look on Cisco for IP SLA



Reply to
Darren Green

Hello, thank you for your answer,

"Darren Green" ha scritto nel messaggio news: snipped-for-privacy@l64g2000hse.googlegroups.com...

Hello I have read about IP SLA but I did not find any examples suitable for my personal situation.

Some questions:

a) So, since the SHDSL is the main link, and just if the SHDSL link is down, the ADSL will take over, I need to set the IP SLA commands on the SHDSL router only, right?

b) In this way, in the HSRP I will monitor both the status of the ATM0/0 interface AND the "ip sla entry number 1" right?

c) But how can I set, ping every 30 seconds and if three pings fail, re-route the connection? I can set the frequency of 30 seconds, but not how many pings need to be failed to lower the priority of the HSRP router.

d) To set "how much decrease the priority" I could use this command, standby

1 track 1 decrement 20, right?

e) > track 1 rtr 1 reachability delay down 10 up 20

this will delay the time to 10 seconds to put the HSRP router "offline", right?

Thank you in advance

Reply to
Elia Spadoni


Yes, I was only giving you an example. You could track the interface as well as the IP SLA entry 1, this is what I normally prefer to do

I would need to check the IP SLA documentation at cisco.com. However, remember that HSRP will ordinarily take over is 3 x HSRP hellos are missed and the default is normally 10 x secondary. YOu could modify this timer to 30 seconds also. May be easier.

Yes I believe so. I normally just have my HSRP priority set to 105. The standard decrement in HSRP is 10 and the default priority 100. If my ATM0/0/0 fails or my IP SLA fails, HSRP goes down to 95 and my secondary takes over.

Again I would need to refer to the IP SLA documentation on line at cisco.com. I will try an take a look a little later today.



Reply to

Hello, thank you again for your answers.

I have read some docs and solved some of my doubts... :)


"Darren" ha scritto nel messaggio news:481820c8$1 snipped-for-privacy@mk-nntp-2.news.uk.tiscali.com...

I haven't seen in the docs a sort of threshold, example, I ping every 30 secs the upstream router, If I fail for example threee times It will consider the upstream router unreachable.

Ok I set the main to 105 and the secondary to 95. Today I will test live! since I just edited the conf remotely.

That should as I wrote, it should be the delay.

Reply to
Elia Spadoni

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