IP SLA for failover

[deepthirajt]

I have the below setup and I want to get a Cisco router to enable failover between my ISP links.

At the branch end, failover happens as there are only connected to the Headoffice MPLS lines.

Whereas in the Headoffice, failover does not happen, and we have been manually changing the priority of the route.

The NPA that we have is to introduce a Cisco router between the HO Firewall and the ISP MPLS links inorder to actively monitor the the two paths and automatically choose the secondary ISP incase of primary link failure.

Fortigate 300A - Headoffice

Foritgate 50B - Branch

Could you please suggest a suitable router that can cater to my requirement [it is a small business] and also help me configure this setup?

Thanks!!

[r.kukreja · Accepted solution]

http://www.cisco.com/en/US/products/hw/vpndevc/ps2030/products_configuration_example09186a00806e880b.shtml

you should go with this link, if you want only to monitor on router go with single router and terminate both link create primary and backup then sla configuration for the respective tracks.

please rate this post if helpful

Regards,

rajat

[deepthirajt]

Thanks Rajat!

Like I have mentioned earlier, I need a basic router that can help me configure this. Could you please suggest a model number perhaps?

[cadet alain · Accepted solution]

Hi,

Any router should be good to do reliable static routes with ip sla.

Regards.

Alain.

[deepthirajt]

Thanks Alain!

Can I try this setup with a 1841??

[tommyboay]

Hi Raj,

No problem, 1800 ISR series and above will work just fine with IP SLA.

Be careful as the commands are slightly changing depending on the IOS train release you'll choose.

Tom

[deepthirajt]

Since this is purely for testing purpose, I will get an 1841, IOS 12.4 onwards and implement it!

Will this work?

http://www.firewall.cx/cisco-technical-knowledgebase/cisco-routers/813-cisco-router-ipsla-basic.html

Could you tell me what commands I can use to configure the IP SLAs?

[cadet alain]

Hi,

ip sla syntax is IOS version dependant but if you've got 12.4 then look at the configuration guide for 12.4

http://www.cisco.com/en/US/docs/ios/12_4/ip_sla/configuration/guide/hsicmp.html

For the tracking look here: http://www.cisco.com/en/US/docs/ios/12_3/12_3x/12_3xe/feature/guide/dbackupx.html

Regards.

Alain.

[tommyboay]

It will work just fine. The commands from your link are usable on 12.4 T release.

So just make sure you pick a T release on your 1841 and you can follow your article as a procedure.

For other releases, you'll need to use the ip sla monitor commands. Here is a link :

http://www.cisco.com/en/US/docs/ios/12_4/ip_sla/configuration/guide/hsicmp.html#wp1027188

[deepthirajt]

Can I try implementing this setup using a Cisco packet tracer?

[cadet alain]

Hi,

No I don't think it is implemented in PT but you can lab it with GNS3 without any problem even if 1841 is not supported on GNS3 so you'll have to use 3660 router.

Regards.

Alain.

[deepthirajt]

I have a Cisco 1941-k9 router provided by the ISP in my premises.

But I am not sure if IP SLA is a feature that comes along with this router or if I should get a license?

[cadet alain]

Hi,

no need for a licence for this feature. Just grab it and try to configure but it should be ok normally.

Regards.

Alain.

[deepthirajt]

Thanks a ton Alain!!

I will do that

[deepthirajt]

I am unable to remove the 1941 router as it will disturb the present ISP setup.

Is there any way that I can get this setup implemented in a simulator/lab?