I'll descript this question in more details:
1. Two internet connections on the same router with pppoe both.
2. load balance default route:
nexthop via a.a.a.a dev ppp0 weight 1
nexthop via b.b.b.b. dev ppp1 weight 1
3. telnet to remote server through ppp1 first time, and maybe 10 minutes later, telent disconnected.
Something I found:
1. route cache will be flushed every 10 minutes by defualt(/proc/sys/net/ipv4/route/secret_interval)
2. after 10 minutes later, caches are flushed; then packets in telnet connection will be routed again;
at this time, multipath may choose another nexthop, e.g. ppp0
3. packets with ppp1 source ip transmited out from ppp0, and telnet disconneted
So, How do I fixed this situation?
Thank a lot!