BGP Incoming traffic

[Siddique]

I have single router connected with 2 different ISP. One link is 10G interface 1 and another link is 1G interface 2. Can I control all incoming traffic 70% via interface 1 as this is 10G link and 30% traffic incoming via interface 2 as this is 1G link. Is it possible through BGP? If possible please share the link or config link.    

Thanks a Lot.

[Richard Burts]

We do not know much about your environment and that makes it difficult to give good advice. But thinking in general terms this is what I would advise: controlling inbound traffic is usually achieved by manipulating what you advertise to your BGP neighbors. If you advertise multiple prefixes (and especially if those prefixes are provider independent addresses) you might be able to use AS prepending to make some prefixes prefer one ISP while other prefixes prefer the other ISP.

But I am guessing that you do not advertise multiple prefixes to your BGP neighbors. In that case the alternative that I would suggest is to use some kind of Policy Based Routing to control how you send traffic to the Internet to achieve 70% to one ISP and 30% to the other ISP. This would result in some type of sharing of incoming (response) traffic. 

[Siddique]

Thanks for your reply.  

If possible can you share what kind of PBR can I use to achieve 70% and 30% outgoing traffic. 

Thanks 

[Jon Marshall]

It is really for you to work out. 

PBR allows you send traffic from specific subnets to a configured next hop IP so you would need to work out what traffic to send to which hop ie. you must have some idea of what accounts for 70% of your traffic so you can send it via the 10Gbps link. 

And this will only affect traffic going to the internet but if you are using NAT on the router the return traffic may well follow the same path, but it may not. 

It is also not clear what public IP subnets you have and what you are advertising and receiving from the ISPs so it may be that PBR is not the best option. 

Perhaps you can provide some more details ? 

Jon

[Richard Burts]

I agree with Jon that it is difficult to give good advice when we know so little about your environment. In particular it would be helpful if we knew whether you have any Public IP addresses (and if so some information about how they are used). What, if anything, do you advertise to the ISPs? Does either of the ISP advertise to you more than just the default route? Assuming that you are doing normal NAT for traffic originating inside your network, then the response traffic should use the same path returning to your network, which would help in achieving your goal of balancing. Is there any traffic originated in the Internet and sent to something inside your network? If so what are the details of that traffic?

The more common approach in PBR is to separate traffic based on the source address. So some subnets might send their outbound traffic using the lower bandwidth ISP while more subnets would send their outbound traffic using the higher bandwidth ISP. Another approach might be to send traffic that is not interactive (FTP, etc) using the lower bandwidth ISP and send interactive traffic (HTTP/HTTPS, etc) using the higher bandwidth ISP.

[Siddique]

Thank for your reply.

This router directly connected with ISP router without NAT. and I accept 10000 route from ISP.

I am sharing 2 prefix with ISP.

Basic bgp neighboring configuring done. Now how i can do load-balance  70% and 30% ?

Thanks

[Richard Burts]

The information that you provide is interesting, but not enough for us to be able to give much advice. I am surprised that you connect to ISP without NAT. Does your network use NAT but it is done somewhere else? Or does your network use Public IPs and so does not need NAT?

If you accept 10000 routes from ISP is that from a single ISP or do both ISP send a number of routes? Perhaps the output of these commands would be helpful:

show ip bgp

show ip bgp neighbor