a = "3ffe:1::/24"
b = "3ffe:2::/24"
l = "3ffe::1"
p = "3ffe:100::1"
flow esp out from 3ffe:1::/24 to 3ffe:2::/24 local 3ffe::1 peer 3ffe:100::1 type require
flow esp in from 3ffe:2::/24 to 3ffe:1::/24 local 3ffe::1 peer 3ffe:100::1 type require