Interface TunnelAddOptions

Allow remote endpoint on the local host. Note: only IPv6 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.

Note: only GRE tunnels.

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.

See

tos

Set a fixed encapsulation limit. Default is 4. Note: only IPv6 tunnels.

Set a fixed flowlabel. Note: only IPv6 tunnels.

See

ttl

See

csum

Enable IPv4 DF suppression on this tunnel. Normally datagrams that exceed the MTU will be fragmented; the presence of the DF flag inhibits this, resulting instead in an ICMP Unreachable (Fragmentation Required) message. Enabling this attribute causes the DF flag to be ignored.

See

key

See

seq

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.

Note: only GRE tunnels.

Set the fixed local address for tunneled packets. It must be an address on another interface of this host.

Set the tunnel mode. Available modes depend on the encapsulating address family.

Select the tunnel device name.

See

{@link['allow-localremote']}

See

{@link['ignore-df']}

Disable Path MTU Discovery on this tunnel. It is enabled by default. Note that a fixed ttl is incompatible with this option: tunneling with a fixed ttl always makes pmtu discovery.

See

pmtudisc

See

csum

See

key

See

seq

XXX.

Set the remote endpoint of the tunnel.

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.

Note: only GRE tunnels.

See

tos

Set the type of service (IPv4) or traffic class (IPv6) field on tunneled packets, which can be specified as either a two-digit hex value (e.g. c0) or a predefined string (e.g. internet). The value inherit causes the field to be copied from the original IP header. The values inherit/STRING or inherit/00..ff will set the field to STRING or 00..ff when tunneling non-IP packets.

The default value is 00.

Set a fixed TTL (IPv4) or hoplimit (IPv6) 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.