My Testing Network:
+---------------------------+ +-------------+
| Internet |---| z.z.z.z |
+---------------------------+ +-------------+
| |
| |
| ppp0 x.x.x.x |ppp0 y.y.y.y
+-----------+ +-------------+
| Server1 |eth1 |Server2 |
| |-------| |
+-----------+ eth1+----------- -+
|
| eth2 172.31.0.254/16
Server1 eth1: 172.30.0.1/16, Server2: 172.30.0.2/16
Server1's ip rule show
0: from all lookup local
32765: from 172.31.0.0/16 to z.z.z.z lookup 10
..... lookup main
.... lookup 253
Server1's ip route show:
x.x.x.1 dev ppp0 proto kernel scope link src x.x.x.x
172.30.0.0/16 dev eth1 proto kernel scope link src 172.30.0.1
172.31.0.0/16 dev eth2 proto
................................172.31.0.254
127.0.0.0/8 .... lo
default
nexthop via 172.30.0.2 dev eth1 weight 1
nexthop dev ppp0 weight 1
ip route show table 10:
default dev eth1 scope link
iptables rule:
iptables -t nat -A POSTROUTING -s 172.31.0.0/16 -d 0.0.0.0/0 \
-o ppp0 -j MASQUERADE
iptables -t nat -A POSTROUTING -s 172.31.0.0/16 -d 0.0.0.0/0 \
-o eth1 -j SNAT --to 172.30.0.1
Server2's ip rule show:
0: from all lookup local
..... lookup main
.... lookup 253
Server2's ip route show:
y.y.y.1 dev ppp0 proto kernel scope link src y.y.y.y
172.30.0.0/16 dev eth1 proto kernel scope link src 172.30.0.1
127.0.0.0/8 .... lo
default
nexthop via y.y.y.1 dev ppp0
iptables rule:
iptables -t nat -A POSTROUTING -s 172.30.0.0/16 -d 0.0.0.0/0 \
-o ppp0 -j MASQUERADE
My purposes are:
1: load sharing with ppp0 and eth1.
2. when trying connect to z.z.z.z, It should use eth1.
( Now, for test, eth1 is private network but final purpose It will be
changed to public network.)
In this situation, the 172.31.0.0/16 network can't establish connection to
z.z.z.z.
When I delete the rule (ip rule del from 172.31.0.0/16 to z.z.z.z lookup
10), The connection is established.
And the other question,
Why the source IP of the packet that going out from eth1 have ppp0's IP
address?
(In my result, It's really happened..
What's wrong in upper configuration?
thanks.
