|MOBILEIP(4)||Device Drivers Manual||MOBILEIP(4)|
mobileipdriver provides IP tunnel construction using the Mobile IP (RFC 2004) encapsulation protocol
mobileip datagrams (IP protocol number 55)
are encapsulated into IP using a small encapsulation header. This protocol,
in line with the RFC, only supports encapsulating IPv4.
The MTU is set to 1488 by default. This may not be an optimal value depending on the link between the two tunnel endpoints, but it can be adjusted via ifconfig(8).
For correct operation, the route to the tunnel destination must not go over the interface itself. This can be implemented by adding a distinct or a more specific route to the tunnel destination than the hosts or networks routed via the tunnel interface. Alternatively, the tunnel traffic may be configured in a separate routing table to the encapsulated traffic.
mobileip interfaces support the following
ioctl(2)s for configuring tunnel
SIOCSLIFPHYADDRstruct if_laddrreq *
SIOCGLIFPHYADDRstruct if_laddrreq *
SIOCSLIFPHYRTABLEstruct ifreq *
SIOCGLIFPHYRTABLEstruct ifreq *
Host X --- Host A ----------- MobileIP ------------ Host D --- Host E \ / \ / +------ Host B ------ Host C ------+
On Host A (OpenBSD):
# route add default B # ifconfig mobileipN create # ifconfig mobileipN tunnel A D # ifconfig mobileipN A D netmask 255.255.255.255 # route add E D
On Host D (OpenBSD):
# route add default C # ifconfig mobileipN create # ifconfig mobileipN tunnel D A # ifconfig mobileipN D A netmask 255.255.255.255 # route add D E
The route domain used for the encapsulated traffic may be set using ifconfig(8) and the tunneldomain argument:
# ifconfig mobileipN tunneldomain 1
mobileipdriver was split off from gre(4) in OpenBSD 6.3.
|February 7, 2018||OpenBSD-current|