>Number:         9920
>Category:       kern
>Synopsis:       gre and ipip documentation not complete, wrong, or something
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          doc-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Apr 17 21:00:00 PDT 2000
>Closed-Date:
>Last-Modified:
>Originator:     Andrew Brown
>Release:        1.4X as of 20000416
>Organization:
	none...just me.
>Environment:
System: NetBSD this 1.4X NetBSD 1.4X (THAT) #2: Sun Apr 16 15:13:55 EDT 2000 root@this:/usr/src/sys/arch/i386/compile/THAT i386


>Description:

	i figured i'd set up a tunnel (or two) since i have current at
home and it ought to be fun.  man gre.  okay...played around for a
bit.  got it going a few hours later.  then broke it.  got it going
again the next day (after a cvs update, a new kernel, and a new
userland build, but i don't think that's it).  conclusions:

	gre: seems to work fine, even if the documentation leaves a little
		and isn't quite right elsewhere
	ipip: seems to send but not receive.

>How-To-Repeat:

	read docs.  try it.  become confused.  periodically lament the
lack of bpf support for gre and ipip interfaces and then wonder what
that would do for you anyway.

>Fix:

on gre.4

	* the source and destination given to the ifconfig gre0
command don't need to be the same as the source and destination given
to the greconfig line.
	* the documentation should describe the difference between the
addresses of the two endpoints and the addresses of the source and
destination of the tunne.  specifically, the local tunnel endpoint
will be the address used for local connections out over the tunnel,
whereas the tunnel source will be the ip source address of the
encapsulated packets.
	* some ciscos apparently don't support the ip mobility
protocol.
	* the example configuration for the remote netbsd tunnel
endpoint looks a little incomplete, nut i've not tried it, so i can't
say for sure.

on ipip.4

	* the cisco configuration given is lacking

		tunnel mode ipip

which will keep it from working properly.  cisco tunnels default to
gre encapsulation.
	* i can apparently send, but not receive.

note: i was just gonna send some man page patches (and i will) but i'm
too tired right now to think in roff.  :)
>Release-Note:
>Audit-Trail:
>Unformatted: