etherip(4) - NetBSD Manual Pages

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ETHERIP(4)              NetBSD Kernel Interfaces Manual             ETHERIP(4)


NAME

     etherip -- EtherIP tunneling device


SYNOPSIS

     pseudo-device etherip


DESCRIPTION

     The etherip interface is a tunneling pseudo device for Ethernet frames.
     It can tunnel Ethernet traffic over IPv4 and IPv6 using the EtherIP pro-
     tocol specified in RFC 3378.

     The only difference between an etherip interface and a real Ethernet
     interface is that there is an IP tunnel instead of a wire.  Therefore, to
     use etherip the administrator must first create the interface and then
     configure protocol and addresses used for the outer header.  This can be
     done by using ifconfig(8) create and tunnel subcommands, or SIOCIFCREATE
     and SIOCSLIFPHYADDR ioctls.

   Packet format
     Ethernet frames are prepended with a EtherIP header as described by RFC
     3378.  The resulting EtherIP packets will be encapsulated in an outer
     packet, which may be either an IPv4 or IPv6 packet, with IP protocol num-
     ber 97.

   Ethernet address
     When a etherip device is created, it is assigned an Ethernet address of
     the form f2:0b:a5:xx:xx:xx.  This address can later be changed through a
     sysctl node.

     The sysctl node is net.link.etherip.<iface>.  Any string of six colon-
     separated hexadecimal numbers will be accepted.  Reading that node will
     provide a string representation of the current Ethernet address.

   Security
     The EtherIP header of incoming packets is not checked for validity.  This
     is because there seems to be some confusion about how such a header has
     to look like.  For outgoing packets, the header is set up the same way as
     done in OpenBSD, FreeBSD, and Linux to be compatible with those systems.

   Converting from previous implementation
     A tunnel configured for the previous (undocumented) implementation will
     work with just renaming the device from gif to etherip.


SEE ALSO

     bridge(4), gif(4), inet(4), inet6(4), tap(4), ifconfig(8)


HISTORY

     The etherip device first appeared in NetBSD 4.0, it is based on tap(4),
     gif(4), and the former gif-based EtherIP implementation ported from
     OpenBSD.


BUGS

     Probably many.  There is lots of code duplication between etherip,
     tap(4), gif(4), and probably other tunnelling drivers which should be
     cleaned up.

NetBSD 5.1.2                   November 23, 2006                  NetBSD 5.1.2