Re: Routing over multiple interfaces

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

Le mercredi 10 novembre 2010 à 14:50 +0000, David Woodhouse a écrit :
> On Mon, 2010-11-01 at 22:35 +0100, Eric Dumazet wrote:
> > 
> > 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
> 
> That works; thanks. Or it should do... there's a slight complication
> right now in that one of my lines is actually routed through a separate
> ADSL<->Ethernet box, because one of the ports on my Solos card is a bit
> shagged and syncs a lot slower than it should. So it's actually eth1 and
> ppp1 that I'm sharing. That should be fixed relatively soon as they're
> sending me a new box.
> 
> There's a minor issue with this setup though — ideally, any given TCP
> connection would tend to use the *same* interface as much as possible,
> and only 'overflow' onto the other interface if it's actually saturating
> the uplink on the first. That would tend to reduce the amount of packet
> re-ordering. At the moment it will split outbound packets over both
> lines even when they're relatively idle, introducing packet re-ordering
> where it wasn't really necessary.
> 
> That said, the world is supposed to cope with packet re-ordering, so I'm
> not going to lose a lot of sleep over it. And I have a feeling the
> downstream link from the ISP does it exactly the same.
> 

Its a bit problematic, as you said you want to use both links to do one
upload ;)

Maybe it is possible to instruct teql to try to not change links unless
one link is full...