Load options for 2 different Internet Connections

[angel-moon]

Hello All,

I have 2 Internet connections coming into a 6800  2 different ISPs.  50Mbps and 100Mbps.  I would like to use both of them at the same time.  Can someone tell me what my options are and the pros/cons of each?  I know there is load sharing but I have heard that kills apps like Skype, etc.

Thanks in advance.

All replies rated.

[Richard Burts]

Typically the things that impact apps like Skype etc are things that produce out of order packets or that introduce variability into the forwarding rate such as sending some of the packets on one forwarding path and sending other packets on a different forwarding path. You are most likely to get that if you implement per packet load sharing. As long as you do per destination/per flow load sharing then apps like Skype should be ok.

How you do load sharing depends a bit on how things are set up with your ISPs. Are you running a dynamic routing protocol with them?

HTH

Rick

[angel-moon]

Thanks everyone.  BGP will be used

[Richard Burts]

It helps to know that you will be using BGP with the ISPs. Note that by default if you receive an advertisement for the same route from both ISPs that BGP will choose one of them as the route to use.So to use both links you need to make sure that some things are advertised by one ISP and not the other. The easiest way to do this is to negotiate with the providers about what they will advertise. Perhaps one provider will advertise a limited set of routes while the other advertises only the default route. Or perhaps one provider will advertise full routes while the other provider advertises partial routes or perhaps only the default route.

Note that doing what I have described will control your outbound traffic (what you are sending to the Internet) and can achieve use of both links for outbound traffic. Managing to use both link for inbound traffic (what the Internet sends to you) is more tricky. The usual approach to this is that you advertise your address space broken into two parts. To provider 1 you do a normal advertisement of the first part and you prepend the advertisement of the second part to this provider. Then to provider 2 you advertise with prepend the first part of the address space and do a normal advertisement of the second part.

These techniques for controlling your advertisement to the providers work best if you have fairly large address space and have your own provider independent address space. It is more difficult if you have a smaller address space or if you have provider provided address space.

HTH

Rick

[Amit Goyal]

Hi Angel,

You can try implementing PBR for load sharing which is the easiest method of doing it. Other way of achieving load balancing is PFRv2 but tough to implement.

You can refer below link to setup PBR.

https://supportforums.cisco.com/discussion/12696601/two-links-balance-traffic

HTH

-Amit

[Joseph W. Doherty]

Did you want to share proportionally?

Egress or ingress and egress load sharing?

And as Rick asked, what routing protocols are you planning to use, if any?

[MANI .P]

Hi Angel-moon ,

01. Advertise Public IP Pool to both side ISP'S .

02. Create access-list for your internal private IP address .

03.Define two types of route-map ( one for all user and another for app user )

04.match the ACL to route-map's 

05.set the action 

06. Defined into the BGP .

i hope it would be clarified & please let me know if anything need.

Regards,

Mani