rp_filter on use:
echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter
- and
+ or
echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
Note that some distributions enable it in startup scripts.
config NET_IPGRE
tristate "IP: GRE tunnels over IP"
+ depends on IPV6 || IPV6=n
help
Tunneling means encapsulating data of one protocol type within
another protocol and sending it over a channel that understands the