X-Git-Url: http://git.ozlabs.org/?p=ppp.git;a=blobdiff_plain;f=FAQ;h=9a1675a3eab5147145a3dc0d87dd8ccdcb75e59f;hp=24555446aa9c3301b73b5de337e652d070ba87f1;hb=e5ad7e3dbf232955054ee90e54cebd6ee9533a85;hpb=40f56b1dddffc7393022d7d4d31a360a8b2ce7f7

diff --git a/FAQ b/FAQ
index 2455544..9a1675a 100644
--- a/FAQ
+++ b/FAQ
@@ -440,3 +440,70 @@ with Deflate, it's hard to get a high output data rate from the
 compressor, simply because it compresses strings of nulls so well that
 it has to eat a very large amount of input data to get each byte of
 output.
+
+
+------------------------------------------------------------------------
+
+Q: I get messages saying "Unsupported protocol (...) received".  What do
+these mean?
+
+A: If you only get one or two when pppd starts negotiating with the
+peer, they mean that the peer wanted to negotiate some PPP protocol
+that pppd doesn't understand.  This doesn't represent a problem, it
+simply means that there is some functionality that the peer supports
+that pppd doesn't, so that functionality can't be used.
+
+If you get them sporadically while the link is operating, or if the
+protocol numbers (in parentheses) don't correspond to any valid PPP
+protocol that the peer might be using, then the problem is probably
+that characters are getting corrupted on the receive side, or that
+extra characters are being inserted into the receive stream somehow.
+If this is happening, most packets that get corrupted should get
+discarded by the FCS (Frame Check Sequence, a 16-bit CRC) check, but a
+small number may get through.
+
+One possibility may be that you are receiving broadcast messages on
+the remote system which are being sent over your serial link.  Another
+possibility is that your modem is set for XON/XOFF (software) flow
+control and is inserting ^Q and ^S characters into the receive data
+stream.
+
+
+------------------------------------------------------------------------
+
+Q: I get messages saying "Protocol-Reject for unsupported protocol ...".
+What do these mean?
+
+A: This is the other side of the previous question.  If characters are
+getting corrupted on the way to the peer, or if your system is
+inserting extra bogus characters into the transmit data stream, the
+peer may send protocol-reject messages to you, resulting in the above
+message (since your pppd doesn't recognize the protocol number
+either.)
+
+
+------------------------------------------------------------------------
+
+Q: I get a message saying something like "ioctl(TIOCSETD): Operation
+not permitted".  How do I fix this?
+
+A: This is because pppd is not running as root.  If you have not
+installed pppd setuid-root, you will have to be root to run it.  If
+you have installed pppd setuid-root and you still get this message, it
+is probably because your shell is using some other copy of pppd than
+the installed one - for example, if you are in the pppd directory
+where you've just built pppd and your $PATH has . before /usr/sbin (or
+wherever pppd gets installed).
+
+
+------------------------------------------------------------------------
+
+Q: Has your package been ported to HP/UX or IRIX or AIX?
+
+A: No.  I don't have access to systems running HP/UX or AIX.  No-one
+has volunteered to port it to HP/UX.  I had someone who did a port for
+AIX 4.x, but who is no longer able to maintain it.  And apparently AIX
+3.x is quite different, so it would need a separate port.
+
+IRIX includes a good PPP implementation in the standard distribution,
+as far as I know.