linux multipath routing load balance

Question

I would like to know how to load balance two Business DLS links which have fixed IPs. I believe it would look something like this:

ip route add default scope global \
                     nexthop via gatewayDLS1 dev interface1 weight 1 \
                     nexthop via gatewayDLS2 dev interface2 weight 1

Is this be all I need in order to get multipath routing? Please, give me a more detailed answer if possible, thanks you.

Are they both from the same provider and do you have real, public IPv4 addresses for things on your side of the gateway? I.e. are you running nat? — Flexo, Jun 03 '11 at 15:48
@alan they are both from the same provider, I don't know if it is from the same dslam, but they have different fixed ipv4 address — user52883, Jun 03 '11 at 15:52

score 4 · Answer 1 · edited Jun 22 '21 at 06:20

4

As you already figured out, you just can work with a multipath route using equal weights. But the granularity of the balancing will be rather bad - all requests to the same destination IP address will go through the same link. You might want something more finely tunable here - which you can get by adding a couple of iptables rules - this howto from tipsternet.com might give you a starting point.

For some background information there is a well-written section about multipath routing in Understanding Linux Network Internals (C.Benvenuti) which is even available online.

edited Jun 22 '21 at 06:20

Community

1

answered Jun 03 '11 at 21:53

the-wabbit

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Could you write a little bit more on why all the connection to the same destination go through the same link in such configuration? I'm just trying to figure this out, and even started a question here: http://unix.stackexchange.com/questions/284416/ – Mikhail Morfikov May 20 '16 at 12:36

linux multipath routing load balance

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