Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

reg:isp faiover

Iam having 3 links with 2 different ISP for the internet traffic. i want to achieve the 3 links active at the same time for internet traffic & the same time i need failover for this links.

8 REPLIES
New Member

Re: reg:isp faiover

is all 3 link are on same router ?

New Member

Re: reg:isp faiover

Yes sir,

3 links on the same router

Regards

srinivas.D

9246571397

Re: reg:isp faiover

Default route pointing to the 3 interfaces could be a solution for outgoing traffic, but incoming traffic would be a concern.

There are 2 methods to solve this: either use BGP with the ISP's, or use a hardware link load-balancer. Choice is entirely with admin based on his expertise over BGP.

Re: reg:isp faiover

HI,

Verify the possibility of Bundling the 3 Links for further usage.

As i know, Bundling will provide the Load Balancing as well as Fail over requirement.

Pls Rate if Helps

Best Regards,

Guru Prasad R

New Member

Re: reg:isp faiover

Dear guruprasad,

Thanks for ur valuble reply and if u dont mind can u explain clearly what is ment by bundling.plz give any exampls for this.

Regards

srinivas.D

9246571397

New Member

Re: reg:isp faiover

If you are using multiple ISPs you will not be able to bundle the circuits. This typically only works when all links terminate in a single device... on both ends of the links.

As for a hardware load balancer, that will only work for outbound traffic, not inbound.

IMHO BGP is going to be your only real option when doing multi-carrier bidirectional load balancing...

Hall of Fame Super Gold

Re: reg:isp faiover

Actually, "hardware" load balancers can also balance inbound traffic. By virtue of NAT, they do so by allocating more TCP outgoing requests to circuits where more incoming traffic is wanted at any give time.

Since for most installations incoming is more than outgoing, the resulting unbalance on outgoing traffic is not a concern.

BGP is simply not possible for most installations. So what is done, is NAT to multiple ISP, with multiple static routes and multiple NAT statements. This works reasonably well. For the case in question, it wold be advantageous if the ISP providing two links, was to bundle them using Multilink PPP.

Hope this helps, please rate post if it does!

Re: reg:isp faiover

HI Srinivas, [Pls Rate if HElps]

Sorry for the late reply.

Bundling should be possible by using Multilink PPP but Bundling has to be done end-to-end (ie., at your customer end and at service provider end).

If not means, the Outbound traffic can be load balanced to various link but the inbound traffic from ISP cannot be assured.

Its better to speak to your ISP reg this requirement.

Note: 3 Links from 2 different ISP's and with this Scenario the Bundling Concept will not work in Normal.

Whereas the 1" Link from a different ISP can be kept as Failover purpose and 2" Link from an ISP can be Bundled with the help of Service provider. So you have Failover + Load Balancing facility availaible.

DO RATE all HELPFUL Posts

Best Regards,

Guru Prasad R

131
Views
0
Helpful
8
Replies