Re: Aggregating 2 ISP links (DSL)

From: Brane (b_b_at_net.hr)
Date: 05/05/05 

Date: Thu, 5 May 2005 19:25:13 +0200

On 5 May 2005 09:32:40 -0700, jetmarc@hotmail.com wrote:

> Hi,
>
> to increase total bandwith for a LAN, I try to aggregate two
> DSL links. Each of the links has one single WAN IP, and a
> NAT-routing modem attached to it. Both listen to the same
> LAN as gateway. I have a linux box available to dedicate it
> to the routing.
>
> So far, I achieved partial success, using the "ip route"
> command with the "nexthop" option:
>
> ip route add default scope global \
> nexthop via $DSL1_IP dev eth0 weight $DSL1_DN \
> nexthop via $DSL2_IP dev eth0 weight $DSL2_DN
>
> Then I set the linux box as default gateway on all desktops.
> All traffic is sent to the linux box, and then redirected by
> the balancing algorithm to either of the DSL modems. There
> it is NAT'ed and sent out to the WAN.
>
> However, this setup causes trouble on incoming connections.
> Lets say I configure the SSH access on the first DSL modem
> (NAT port forward to the linux box). The incoming connection
> starts on an unknown WAN machine, passes through the first
> DSL modem and arrives at the linux box. The reply packet
> is handled by the load-balancing algorithm and a route is
> created in the cache, forwarding it to either of the two DSL
> modems. If by chance it happens to be the same first modem,
> the connection succeeds. If the other one happens to be
> chosen, the packet is forwarded to it, where it is NAT'ed
> with a _different_ WAN IP and sent to the WAN SSH client.
> Obviously it must be rejected there, because although it is
> a correct reply packet, it originates from a different source
> IP and port number, and cannot be matched to the outgoing
> SSH connection.
>
> Is there a way to avoid this to happen? I can think of
> creating static routes for connections on the SSH port, and
> outgoing WWW ports, etc. But is this really the way to go?
>
> Marc

man ip :-))
ip rule add dev ppp0 table 1
ip rule add dev ppp1 table 2
ip route add from (external 1) ...
ip route add from (externlal 2) ...
ip route add default equalize nexthop ....

check the ip man pages and if you can manage it
ask and i can send you a working config
regards
brane

Relevant Pages

  • Re: what is the 1394 connection ?
    ... Switch ISP's, buy/rent some expensive DSL modem, ... It is not necessary to drill a hole in your wall if you purchase DSL ... and very low monthly charges. ... >And now my 1394 connection was enabled after the visit to the shop. ...
    (microsoft.public.windowsxp.newusers)
  • Phone use kills DSL connection, even with whole-house splitter
    ... Well, I installed a whole-house splitter, thinking that my problem was ... DSL connection. ... again with RJ-12 plugs from splitter to DSL modem. ... dial, without losing the DSL connection, but as soon as ringing begins on ...
    (comp.dcom.xdsl)
  • Re: Windows XP fails to renew my IP address
    ... I have a very simply plain-vanilla DSL set up at home. ... plugs into the WAN socket of my wireless router and one of the 4 open ... DSL connection at home I actually had to set the connection mode to ... The DSL modem does ...
    (microsoft.public.windowsxp.network_web)
  • Re: [SLE] Experiences with Quest DSL?
    ... > on my connection. ... > ethernet port of her new Actiontec DSL modem, connected to Quest DSL. ...
    (SuSE)
  • Re: ifconfig eth0 down works but it wont go up!
    ... > gateway from route table. ... > The web page cited above uses a different command and the man route page ... After hanging up, I can bring DSL ... You shouldn't need to drop eth0 before or after raising a ppp connection. ...
    (comp.os.linux.networking)