multiple pppoe with proxy server

multiple pppoe with proxy server

Im trying to use a Raspbarry pi to to build a proxy server with multiple
pppoe connections. so, i can let my spider easier to change different ip
through proxy server and using different ip address.
Device are : one pppoe modem, one raspbarry pi, one laptop

And here is what i did :
1. build up two pppoe connections by using Raspbarry pi (different ip but
same gateway)
2. setup load balance to make sure two pppoe connect is functional
command :
ip route replace default scope global nexthop dev ppp0 weight 1
nexthop dev ppp1 weight 1
3. setup 2 ip alias
command :
ip address add 192.168.55.11/24 brd + dev eth0 label eth0:0
ip address add 192.168.55.12/24 brd + dev eth0 label eth0:1
4. setup squid server like this :
acl ip1 myip 192.168.55.11
tcp_outgoing_address xxx.xxx.xxx.xxx (the real ip i get from ppp0) ip1

acl ip2 myip 192.168.55.12
tcp_outgoing_address xxx.xxx.xxx.xxx (the real ip i get from ppp1) ip2
5. use other computer to connect it through lan ip and make proxy change
real ip for me

And the question is i found out that the network package will lost by
random, and squid log will show tcp_miss/200 or tcp_miss/503 errors.
Can anyone please give me a direction on this issues or any suggestion to
make this easier ? Thank you