config redirect
        option target 'SNAT'
        option src 'lan'
        option dest 'wan'
        option proto 'all'
        option src_ip '192.168.0.2'
        option src_dip '192.168.88.173'
        option name 'ip1'

config redirect
        option target 'SNAT'
        option src 'lan'
        option dest 'wan'

vtun
    kmod-tun
    liblzo
    zlib
    libopenssl

vtund.conf

options{}
default {}
session{}

在 luci

Network -> Interfaces -> Wan