loxilb 0.9.8 requires --egress flag for firewall
rule to masquerade/SNAT GREEN network source IP
for Internet access. to access host in RED network
another firewall rule is required. see [0].
[0]: https://github.com/loxilb-io/loxilb/issues/957
Signed-off-by: Vincent Li <vincent.mc.li@gmail.com>