Support externalTrafficPolicy: Local

[loganmc10]

When using klipper-lb, even when setting externalTrafficPolicy: Local, the source IP shows as 172.16.18.1 (the first IP in the cluster cidr range).

It would be nice if it could preserve the IP address of the client, useful for when you need to do a reverse DNS lookup of the client ip

[comphilip]

@loganmc10 Klipper-lb does not change source IP. it supports externalTrafficPolicy: Local. I tried https://comphilip.wordpress.com/2021/05/23/k3s-thing-make-traefik-forward-real-client-ip/