I take part of this back: On Sun, 10 Dec 2000, Paul wrote: > Arthur, > > Thanks for your help. I tried what you suggested, here is the result: > > # /sbin/ip route add default nexthop via 24.141.xxx.1 nexthop via > 64.229.xxx.1 > RTNETLINK answers: Network is unreachable > > So instead, I tried: > > # /sbin/ip route add default nexthop via 24.141.xxx.1 dev eth0 nexthop via > 64.229.xxx.1 dev ppp0 > > # ip route ls > 64.229.xxx.1 dev ppp0 proto kernel scope link src 64.229.xxx.12 > 24.141.xxx.0/22 dev eth0 proto kernel scope link src 24.141.xxx.89 > 127.0.0.0/8 dev lo scope link > default > nexthop via 24.141.xxx.1 dev eth0 weight 1 > nexthop via 64.229.xxx.1 dev ppp0 weight 1 This DOES work. > > and that seemed to work, so I tried: > > # /sbin/ip route add default nexthop dev eth0 nexthop dev ppp0 > > # ip route ls > 64.229.xxx.1 dev ppp0 proto kernel scope link src 64.229.xxx.12 > 24.141.xxx.0/22 dev eth0 proto kernel scope link src 24.141.xxx.89 > 127.0.0.0/8 dev lo scope link > default > nexthop dev eth0 weight 1 > nexthop dev ppp0 weight 1 > This does WEIRD things. I can traceroute to ftp.cdrom.com, but I can't ping it, nor can I ftp to it. > > Now this seems to work. Is there anything wrong with this? Can you take > a guess at why what you suggested didn't work? I think I tried all the > different permutations with addresses, I think the problem must come from > the pppoe interface. > > Now all I have to do is kludge something together for my redundancy, set > up firewalling, and masqerading. > > Thanks, > Paul > > > On Sun, 10 Dec 2000, Arthur van Leeuwen wrote: > > > On Sun, 10 Dec 2000 hesselsp@xxxxxxxxxxxxxxx wrote: > > > > > Well, I think I have the redundancy down... In a kludgy way. Right now I > > > have two default routes. > > > > > route add default gw 24.141.xxx.1 > > > route add default gw 64.229.xxx.1 > > > > Actually, if I understand the code correctly what you do here is in fact > > create a multipath route. A cleaner way to do so is using ip route 2 as > > follows: > > > > ip route add default nexthop via 24.141.xxx.1 nexthop via 64.229.xxx.1 > > > > This explicitly states that you will be using a multipath route and balances > > outgoing routes over the two interfaces. > > > > > I can write a script that if one of connections goes down for x number of > > > pings, then remove the route. > > > > And here's the crux. It would be nice for the kernel to use its idea of > > gateway reachability (in the neighbor cache) to automatically ignore an > > upstream hop in case it is dead. However, for multipath routes, no > > death detection is done on the gateways in the different hops. This is > > quite somewhat different from the single default route behaviour > > > > > Now for the load balancing. > > > > The kernel balances outgoing routes over the upstream interfaces. Unless all > > your packets go to the same address, that should balance your traffic > > already. Other than that there's some code based on EQL that will flush the > > route cache after every packet, thereby smashing the route-balancing down to > > packet-level load balancing. I can't seem to find the URL for that code, > > though, unfortunately. > > > > > Can you point me to documentation on iproute? Other then the Advanced > > > Routing HOWTO, unless I am missing something in it. > > > > http://snafu.freedom.org/linux2.2/iproute-notes.html#doc > > > > There's some more interesting stuff on http://snafu.freedom.org/linux2.2/ > > as well. > > > > Doei, Arthur. > > > > > > -- HEY! I'm a guy like me! --Homer
