X-Git-Url: http://git.ozlabs.org/?p=ppp.git;a=blobdiff_plain;f=FAQ;h=a25f0d5217319d85308a8fa92032d9490306ccf2;hp=24555446aa9c3301b73b5de337e652d070ba87f1;hb=262600f5df1461ecbd29ef3a2579e477bb397769;hpb=40f56b1dddffc7393022d7d4d31a360a8b2ce7f7 diff --git a/FAQ b/FAQ index 2455544..a25f0d5 100644 --- a/FAQ +++ b/FAQ @@ -370,13 +370,9 @@ the server. Thus, it may be necessary to use the `remotename' option to pppd when using PAP authentication so that it can select the appropriate secret from /etc/ppp/pap-secrets. -Microsoft also has a variant of CHAP which they apparently think is -more secure than standard CHAP because they don't store secrets in -clear text on the server. However, a bogus client only needs to know -the encrypted secret to gain access, so the only extra security is -that the bogus client would need to run something other than Windows. -There is a client-side implementation of Microsoft's CHAP in ppp-2.3; -see README.MSCHAP80. +Microsoft also has a variant of CHAP which uses a different hashing +arrangement from normal CHAP. There is a client-side implementation +of Microsoft's CHAP in ppp-2.3; see README.MSCHAP80. ------------------------------------------------------------------------ @@ -440,3 +436,145 @@ 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. + + +------------------------------------------------------------------------ + +Q: Under SunOS 4, when I try to modload the ppp modules, I get the +message "can't open /dev/vd: No such device". + +A: First check in /dev that there is an entry like this: + +crw-r--r-- 1 root 57, 0 Oct 2 1991 vd + +If not, make one (mknod /dev/vd c 57 0). If the problem still exists, +probably your kernel has been configured without the vd driver +included. The vd driver is needed for loadable module support. + +First, identify the config file that was used. When you boot your +machine, or if you run /etc/dmesg, you'll see a line that looks +something like this: + +SunOS Release 4.1.3_U1 (CAP_XBOX) #7: Thu Mar 21 15:31:56 EST 1996 + ^^^^^^^^ + this is the config file name + +The config file will be in the /sys/`arch -k`/conf directory (arch -k +should return sun4m for a SparcStation 10, sun3x for a Sun 3/80, +etc.). Look in there for a line saying "options VDDRV". If that line +isn't present (or is commented out), add it (or uncomment it). + +You then need to rebuild the kernel as described in the SunOS +manuals. Basically you need to run config and make like this: + + /usr/etc/config CAP_XBOX + cd ../CAP_XBOX + make + +(replacing the string CAP_XBOX by the name of the config file for your +kernel, of course). + +Then copy the new kernel to /: + + mv /vmunix /vmunix.working + cp vmunix / + +and reboot. Modload should then work. + + +------------------------------------------------------------------------ + +Q: I'm running Linux (or NetBSD or FreeBSD), and my system comes with +PPP already. Should I consider installing this package? Why? + +A: The PPP that is already installed in your system is (or is derived +from) some version of this PPP package. You can find out what version +of this package is already installed with the command "pppd --help". +If this is older than the latest version, you may wish to install the +latest version so that you can take advantage of the new features or +bug fixes. + + +------------------------------------------------------------------------ + +Q: I'm running pppd in demand mode, and I find that pppd often dials +out unnecessarily when I try to make a connection within my local +machine or with a machine on my local LAN. What can I do about this? + +A: Very often the cause of this is that a program is trying to contact +a nameserver to resolve a hostname, and the nameserver (specified in +/etc/resolv.conf, usually) is on the far side of the ppp link. You +can try executing a command such as `ping myhost' (where myhost is the +name of the local machine, or some other machine on a local LAN), to +see whether that starts the ppp link. If it does, check the setup of +your /etc/hosts file to make sure you have the local machine and any +hosts on your local LAN listed, and /etc/resolv.conf and/or +/etc/nsswitch.conf files to make sure you resolve hostnames from +/etc/hosts if possible before trying to contact a nameserver.