Re: Routing over multiple interfaces

[Eric Dumazet <eric.dumazet@gmail.com>]

Le lundi 01 novembre 2010 à 14:16 -0700, David Miller a écrit :
> From: David Woodhouse <dwmw2@infradead.org>
> Date: Mon, 01 Nov 2010 17:12:02 -0400
> 
> > But when I do a large upload, I find that the kernel is only ever using
> > a *single* link at a time, rather than both. How can I make it use
> > *both* links? It's fine to confine each flow to a single link if it
> > doesn't saturate that link... but once the queue is full, it should
> > overflow onto the other device.
> 
> Once a TCP socket gets a routing cache entry, that's what it uses
> for the rest of the life of the connection.
> 
> The multi-pathing decision happens at the time the routing
> cache entry is created.
> 
> What you want is multi-path routing support in the routing cache.
> 
> We used to have that, but the guy who implemented it (after bugging
> me to integrate it for 4 months straight, non-stop) just did a code
> dump and then disappeared and fixed none of the serious fundamental
> problems which existed in his code.
> 
> After a year of no action, I simply tore out all of his code.
> 
> More recently Ulrich Weber gave a presentation at netfilter workshop
> on some uplink load balancing work he is doing, you might have
> a look at his talk and get in contact with him:
> 
> http://people.astaro.com/uweber/uplink_balancing.pdf
> --

Astaro case is a bit different, since links have different IP addresses,
and a single upload uses a single link anyway because of hashing or
policy that selects one source IP address.

David W. probably wants to use teql or some bonding ?

# tc qdisc add dev ppp0 root teql0
# tc qdisc add dev ppp1 root teql0
# ip link set dev teql0 up
# ip route add default src 90.155.92.214 dev teql0