BGP and HSRP Tracking

[jagdev.dhaliwal]

Hi All,

Is there any way to track the BGP route for the HSRP failover, I f i have  Multihomed BGP netwrok with Two ISPa and load sharing is configured. and HSRP has two groups configured.

Thanks

Jagdev         

[Abzal]

Hi,

By BGP route do you mean default route that ISPs advertising to you? If so, you could track ip route because HSRP support tracking objects.

Give us some more information.

Hope it will help.

Best regards,
Abzal

[jagdev.dhaliwal]

From one ISP (ISP-1) I want to learn a specific Subnet (Eg. 200.10.10.0/24) and from other ISP (ISP -2) default route for rest of internet traffic.  But would also learn deafult route from ISP-1 with lower weight for back up.

Thanks

Jagdev

[John Blakley]

You can track using ip sla and tracking within hsrp. Something like:

ip sla 1

icmp-echo 10.10.10.10 (BGP peer)

frequency 5

ip sla schedule 1 life forever start-time now

track 1 ip sla 1 reachability

int g0/0

ip address 192.168.1.2 255.255.255.0

standby 1 preempt

standby 1 ip 192.168.1.1

standby 1 track 1 decrement 10

When sla fails, tracking will fail and routing should go through your other isp. Does that help?

HTH,
John

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[shillings]

Another method is to not use BGP for outbound failover of the default route, but instead track 2-3 IP addresses within the ISP cloud, using IP SLA echo. This gives you a little more reach into the ISPs network rather than just detecting if your BGP neighborship fails.

IP SLA can be linked to a static route (i.e. default static route.) If a ping repeatedly fails, then the route is withdrawn. Obviously, you'll need a floating static default route via your other ISP, so that it can fail across.

Outbound routing towards ISPs local routes would still use BGP, as would all inbound routing.      

[jagdev.dhaliwal]

Thansk All,

At first place i do not want to track the eBGP peer or any other sytem, I want to use route traking from my Routing table:-

10.10.20.2 -- Next hope IP of PE for ISP1 

Ip route 0.0.0.0 0.0.0.0 10.10.10.2 track 100

Means if i am learing route from ISP1 than the next hope IP for the route would their PE router other wise it would be learing from iBGP and would have next hope IP of my CE2's LAN IP

                |--------CE1------------------PE1

ASA---------|

                |---------CE2-----------------PE2

Thanks

Jagdev

[Abzal]

Hi Jagdev,

You can either track ICMP reachability of ISPs eBGP peer or a specific ip route. It depends on your needs.

Example:

track 10 ip route 1.1.1.0 255.255.255.0 reachability

delay down 10 up 10

int G0/0

ip address 10.0.0.2 255.255.255.0

standby 1 preempt

standby 1 ip 10.0.0.1

standby 1 track 10 decrement 10

About a eBGP peer tracking John already showed you of that example.

Hope it will help.

Best regards,
Abzal

[jagdev.dhaliwal]

Thanks Abzel,

If use your example can i also use next hope IP, beacuse there will always reachebilty to internet eithe via one or other next hope?

Example:

track 10 ip route 1.1.1.0 255.255.255.0 10.10.10.2 reachability

delay down 10 up 10

Thanks

Jagdev

[Abzal]

Hi,

It is a good question indeed   there is no option for interface as I know.

But I think it is possible with threshold option.

You may have a try.

https://supportforums.cisco.com/thread/2119326

http://www.cisco.com/en/US/docs/ios/12_2t/12_2t15/feature/guide/fthsrptk.html#wp1185133

Unfortunatelly I don't have so much experinece with such tracking. Particular subnet that you want to track are you redistributing it to IGP?

Hope it will help.

Best regards,
Abzal