Redundancy link setup help

[terrencepayet]

Hi guys,

Grateful if you could help me with the above subject. I want to setup redundancy between our sites via our ISP ADSL could without causing any loops, and i would like to know which technology will best suit our scenario. I've attached a network diagram for you to undertsand further. Take note that i want to use OSPF on all sites.

Thanks for your quick response.

Regards,

Terence

[Eugene Khabarov]

I think that my answer will be more helpful, if you can provide your current configurations of the SITE_A, B and C

[terrencepayet]

Hi Eugene,

Thanks.

This is a brand new installation. There's no configurations what so ever. I've been ask by my boss to redesign the whole network.

And this is what they've gave me to work with.

I have some ideas on how to setup, see below and advise if am going in the right directions:

• I want to use GRE Tunnels with IPSec and use OSPF for routing.
• i can set OSPF cost on the backup link that is from SITEA to SITEB. or i can use IP SLA.

The rest is straight forward.

What do you think of the above?

Thanks,

Terence

[Eugene Khabarov · Accepted solution]

GRE tunnels with ipsec encryption is good solution, but I suggest you to try DMVPN (mGRE interfaces + NHRP protocol + IPSEC). It will reduce number of interface neede twice in you case and will allow for future growth of your network (adding remote offices)

So in case of GRE Tunnels it is preferred to use dynamic routing between sites whenever it is possible so I would like to suggest you OSPF usage and manage your links preference with OSPF costs.

HTH. Please rate if it was helpful. "Correct answer" will be also pleasant. Thank you.

[terrencepayet]

Thanks Eugene,

I will go with your suggestion.

Thanks again for your helpful post.

Best Regards,

Terence

[Eugene Khabarov]

You are welcome!