name " NAME " (default) select the tunnel device name.
mode " MODE" set the tunnel mode. Available modes depend on the encapsulating address family. Modes for IPv4 encapsulation available: ipip ", " sit ", " isatap " and " gre "." Modes for IPv6 encapsulation available: ip6ip6 ", " ipip6 " and " any "."
remote " ADDRESS" set the remote endpoint of the tunnel.
local " ADDRESS" set the fixed local address for tunneled packets. It must be an address on another interface of this host.
ttl " N" set a fixed TTL N on tunneled packets. N is a number in the range 1--255. 0 is a special value meaning that packets inherit the TTL value. The default value for IPv4 tunnels is: "inherit" . The default value for IPv6 tunnels is: "64" .
tos " T"
dsfield " T"
tclass " T" set a fixed TOS (or traffic class in IPv6) T on tunneled packets. The default value is: "inherit" .
dev " NAME" bind the tunnel to the device NAME so that tunneled packets will only be routed via this device and will not be able to escape to another device when the route to endpoint changes.
nopmtudisc disable Path MTU Discovery on this tunnel. It is enabled by default. Note that a fixed ttl is incompatible with this option: tunnelling with a fixed ttl always makes pmtu discovery.
key " K"
ikey " K"
okey " K" ( " only GRE tunnels " ) use keyed GRE with key K ". " K is either a number or an IP address-like dotted quad. The key parameter sets the key to use in both directions. The ikey " and " okey parameters set different keys for input and output.
csum ", " icsum ", " ocsum ( " only GRE tunnels " ) generate/require checksums for tunneled packets. The ocsum flag calculates checksums for outgoing packets. The icsum flag requires that all input packets have the correct checksum. The csum flag is equivalent to the combination "icsum ocsum" .
seq ", " iseq ", " oseq ( " only GRE tunnels " ) serialize packets. The oseq flag enables sequencing of outgoing packets. The iseq flag requires that all input packets are serialized. The seq flag is equivalent to the combination "iseq oseq" . It isn't work. Don't use it.
"dscp inherit" ( " only IPv6 tunnels " ) Inherit DS field between inner and outer header.
encaplim " ELIM" ( " only IPv6 tunnels " ) set a fixed encapsulation limit. Default is 4.
flowlabel " FLOWLABEL" ( " only IPv6 tunnels " ) set a fixed flowlabel.
dev " NAME" mandatory device name.
prl-default " ADDR"
prl-nodefault " ADDR"
prl-delete " ADDR" "Add or delete " ADDR as a potential router or default router.