Backup link bet Practice

[terrencepayet]

Hi Experts,

I need some advice on what is the best way to configure a backlink as shown in the diagram attached.

I want to allow subnet 172.16.56.0/24 to have access to primary link 172.16.32.0/24 and have a backdoor on secondary link 172.16.48.0/24.

Thanks to advise the best way to achieve this.

Regards,

Terence

[Edison Ortiz]

I recommend running a dynamic routing protocol such as OSPF.

Just enable OSPF in all links and if the connection towards 11.202 is lost, it will communicate via 11.201 and the non-ADSL link.

Regards,

Edison

[shehinpm1]

yes ospf will be the best way to do this,you can change the ospf cost in that interface to make it as primary link.

[terrencepayet]

Hi Guys,

Thanks, but unfortunately OSPF doesn't work on the ADSL link. I've tried everything i can think of. I find it strange as the ISP has configured the ADSL cloud as point to point.

I dont think there's an issue with convergence.

Are there any other means of achieving the backup.

Thanks & Regards,

Terence

[Marwan ALshawi]

You can run gre tunnels over the p2p links then over gre you can run the routing having two gre tunnels in the hub router each tunnel terminate to one of the remote routers and using ospf and ospf cost on the tunnel interfaces you can get active/standby links

HTH

If helpful rate

[terrencepayet]

Hi HTH,

Thanks.

Will OSPF run on the GRE tunnels as explain earlier. OSPF doesn't work on the ADSL link.

Thanks to advise.

Regards,

Terence

[ajay chauhan]

Yes you can use OSPF on GRE .

Ajay

[Marwan ALshawi · Accepted solution]

Hi

Yes the point to to point dsl you need it just to get your tunnel to establish in the tunnel source and destination commands the routing will be unseen by the dsl as it will be encapsulated inside the gre tunnel

Please see the bellow example in your case you do not need IPSec so ignore the IPSec config in this example just see the the rotuign and gre concept

http://www.cisco.com/en/US/tech/tk583/tk372/technologies_configuration_example09186a00800a43f6.shtml

By the way, HTH stand for hope this help :)

If helpful rate

[Marwan ALshawi]

Just to add you might try to use ospf in point to point interface mode or NBMA with neighbor command without gre in the case I think it might work as ospf will use unicast instead multicast.

[terrencepayet]

Hi marwanshawi,

Thanks and sorry for getting your name wrong.

I will try it tonight and we'll advise tomorrow.

Regards,

Terence

[Marwan ALshawi]

Good luck and thanks for the rating

If there is any issue post the bellow of each router

Show ip route

Show ip ospf interface tunnel x

Show run

[terrencepayet]

Hi Marwanshawi,

Thanks a bunch. Ive configured OSPF on GRE, then i've adjusted the OSPF cost so that when the primary link fails it automatically route on the other.

Again thank you very much.

Best Regards,

Terence

[Marwan ALshawi]

Happy it's working and thanks for rating it as resolved

[betproexchange3]

Indeed the highlight to point dsl you want it just to get your passage to lay out in the passage source and objective orders the steering will be concealed by the dsl as it will be epitomized inside the gre burrow

If it's not too much trouble, see the cry model for your situation you needn't bother with IPSec so overlook the IPSec config in this model simply see the rotuign and gre idea betpro signup.