Problem with port 0
fenner at research.att.com
Tue Jan 16 22:19:00 UTC 2007
I'd note that RFC 768 explicitly mentions this possibility:
Source Port is an optional field, when meaningful, it indicates the port
of the sending process, and may be assumed to be the port to which a
reply should be addressed in the absence of any other information. If
not used, a value of zero is inserted.
I think Hug is saying that since the boot loader is the only thing that's
running on the box, it's got no reason to use a port number, so it's
Hug's error message:
>with default tftp - Jan 12 09:37:55 dukeengi01 tftpd: connect: Can't
>assign requested address
is consistent with the following code from in_pcbconnect_setup():
if (sin->sin_port == 0)
which dates back to BSD 4.4 and before.
This is probably not completely wrong, but it's not right in this particular
case - tftpd should be able to connect a UDP socket to a remote port 0 in
order to respond to this request.
(FreeBSD definitely can't send from port 0, but that's OK because we don't
More information about the freebsd-net