ulfougretap: Userspace L2 GRE tunnel over UDP ============================================= Designed for OpenVZ servers running on older kernels without Foo-over-UDP support. USAGE ----- $ autoreconf -i && ./configure && make && make install $ ulfougretap <dev> <local address> <local port> \ <peer address> <peer port> For example, # ulfougretap l2gre0 192.168.1.2 5555 10.0.2.1 5556 Does the same thing as: # ip fou add port 5555 ipproto 47 \ local 192.168.1.2 peer 10.0.2.1 peer_port 5556 # ip link add name l2gre0 type gretap \ local 192.168.1.2 remote 10.0.2.1 ttl 64 \ encap fou encap-sport 5555 encap-dport 5556 BUGS ---- - IPv6 transport is currently not supported. - Features of GRE such as Checksum, Key, or Sequence are not supported. - IP fragment is not supported. Not tested actually. You must properly set MTU.