Hopefully, this helps

Place the below at the bottom of the Custom Rules section.

Beryl

WAN="eth0.2"
iptables -F
iptables -t nat -F -t mangle
iptables -t mangle -I POSTROUTING 1 -o $WAN -j TTL --ttl-set 66
iptables -t mangle -A PREROUTING $WAN -j TTL --ttl-set 66
iptables -t mangle -I POSTROUTING $WAN -o TTL -j --ttl-inc 1

Slate

WAN="eth0.2"
iptables -F
iptables -t nat -F -t mangle
iptables -t mangle -I POSTROUTING 1 -o $WAN -j TTL --ttl-set 117
iptables -t mangle -A PREROUTING $WAN -j TTL --ttl-set 117
iptables -t mangle -I POSTROUTING $WAN -o TTL -j --ttl-inc 1

Linksys

iptables -F
iptables -t nat -F -t mangle
iptables -t mangle -I POSTROUTING 1 -o $(nvram get wan_iface) -j TTL --ttl-set 66
iptables -t mangle -A PREROUTING $(nvram get wan_iface) -j TTL --ttl-set 66
iptables -t mangle -I POSTROUTING $(nvram get wan_iface) -o TTL -j --ttl-inc 1

Firewall Settings