patch-pre2.0.6 linux/Documentation/isdn/syncPPP.FAQ

• Lines: 248
• Date: Sun May 19 15:29:28 1996
• Orig file: pre2.0.5/linux/Documentation/isdn/syncPPP.FAQ
• Orig date: Wed Apr 24 17:00:33 1996

diff -u --recursive --new-file pre2.0.5/linux/Documentation/isdn/syncPPP.FAQ linux/Documentation/isdn/syncPPP.FAQ
@@ -1,32 +1,50 @@
 simple isdn4linux PPP FAQ .. to be continued .. not 'debugged' 
+-------------------------------------------------------------------
 
-Q: pppd,ipppd, syncPPP , asyncPPP .. what is that ?
-  what should I use?
-A: The pppd is for asynchronous PPP .. asynchronous means
-here, the framing is character based. (e.g when
-using ttyI* or tty* devices)
-
-The ipppd handles PPP packets coming in HDLC
-frames (bit based protocol) ... The PPP driver
-in isdn4linux pushes all IP packets direct
-to the network layer and all PPP protocol
-frames to the /dev/ippp* device. 
-So, the ipppd is a simple external network
-protocol handler.
-
-If you login into a remote machine using the
-/dev/ttyI* devices and then enable PPP on the
-remote terminal server -> use the 'old' pppd
-
-If your remote side immediately starts to send
-frames ... you probably connect to a 
-syncPPP machine .. use the network device part
-of isdn4linux with the 'syncppp' encapsulation
-and make sure, that the ipppd is running and 
-connected to at least one /dev/ippp*. Check the 
-isdn4linux manual on how to configure a network device.
+Q01: what's pppd,ipppd, syncPPP , asyncPPP ??
+Q02: error message "this systems lacks PPP support"
+Q03: strange information using 'ifconfig'
+Q04: MPPP?? What's that and how can I use it ...
+Q05: I tried MPPP but it doesn't work 
+Q06: can I use asynchronous PPP encapuslation with network devices
+Q07: A SunISDN machine can't connect to my i4l system
+Q08: I wanna talk to several machines, which need different configs
+Q09: Starting the ipppd, I get only error messages from i4l
+Q10: I wanna use dynamic IP address assignment 
+Q11: I can't connect. How can I check where the problem is.
+Q12: How can I reduce login delay? 
+
+-------------------------------------------------------------------
+
+Q01: pppd,ipppd, syncPPP , asyncPPP .. what is that ?
+   what should I use?
+A: The pppd is for asynchronous PPP .. asynchron means
+   here, the framing is character based. (e.g when
+   using ttyI* or tty* devices)
+
+   The ipppd handles PPP packets coming in HDLC
+   frames (bit based protocol) ... The PPP driver
+   in isdn4linux pushes all IP packets direct
+   to the network layer and all PPP protocol
+   frames to the /dev/ippp* device. 
+   So, the ipppd is a simple externel network
+   protocol handler.
+
+   If you login into a remote machine using the
+   /dev/ttyI* devices and then enable PPP on the
+   remote terminal server -> use the 'old' pppd
+
+   If your remote side immediately starts to send
+   frames ... you probably connect to a 
+   syncPPP machine .. use the network device part
+   of isdn4linux with the 'syncppp' encapsulation
+   and make sure, that the ipppd is running and 
+   conneted to at least one /dev/ippp*. Check the 
+   isdn4linux manual on how to configure a network device.
 
-Q: when I start the ipppd .. I only get the
+--
+
+Q02: when I start the ipppd .. I only get the
    error message "this systems lacks PPP support"
 A: check that at least the device 'ippp0' exists.
    (you can check this e.g with the program 'ifconfig')
@@ -39,12 +57,168 @@
    kernel source tree than the kernel you currently
    run ... 
 
-Q: when I list the netdevices with ifconfig I see, that
+--
+
+Q03: when I list the netdevices with ifconfig I see, that
    my ISDN interface has a HWaddr and IRQ=0 and Base 
    address = 0 
-A: The device is a fake ethernet device .. ignore IRQ and baseaddr
+A: The device is a fake ethernetdevice .. ignore IRQ and baseaddr
    You need the HWaddr only for ethernet encapsulation.
    
+--
+
+Q04: MPPP?? What's that and how can I use it ...
+
+A: MPPP or MP or MPP (Warning: MP is also an 
+   acronym for 'Multi Processor') stands for
+   Multi Point to Point and means bundling
+   of several channels to one logical stream.
+   To enable MPPP negotiation you must call the
+   ipppd with the '+mp' option. 
+   You must also configure a slave device for
+   every additional channel. (see the i4l manual
+   for more)
+   To use channel bundling you must first activate
+   the 'master' or inital call. Now you can add 
+   the slave channels with the command:
+       isdnctrl addlink <device>
+   e.g:
+       isdnctrl addlink ippp0
+   This is different to other encapsualtions of
+   isdn4linux! With syncPPP, there is no automatic
+   activation of slave devices.
+
+--
+
+Q05: I tried MPPP but it doesn't work .. the ipppd
+   writes in the debug log something like:
+   .. rcvd [0][proto=0x3d] c0 00 00 00 80 fd 01 01 00 0a ...
+   .. sent [0][LCP ProtRej id=0x2 00 3d c0 00 00 00 80 fd 01 ...
+
+A: you forgot to compile MPPP/RFC1717 support into the
+   ISDN Subsystem. Recompile with this option enabled.
+
+--
+
+Q06: can I use asynchronous PPP encapuslation
+   over the network interface of isdn4linux ..
+
+A: No .. that's not possible .. Use the standard
+   PPP package over the /dev/ttyI* devices. You
+   must not use the ipppd for this.
+   
+--
+
+Q07: A SunISDN machine tries to connect my i4l system,
+   which doesn't work.
+   Checking the debug log I just saw garbage like:
+!![ ... fill in the line ... ]!!
+
+A: The Sun tries to talk asynchronous PPP ... i4l
+   can't understand this ... try to use the ttyI*
+   devices with the standard PPP/pppd package
+
+A: (from Alexanter Strauss: )
+!![ ... fill in mail ]!!
+
+--
+
+Q08: A wanna talk to remote machines, which need
+   a different configuration. The only way
+   I found to do this is to kill the ipppd and
+   start a new one with another config to connect
+   to the second machine. 
+
+A: you must bind a network interface explicitly to
+   an ippp device, where you can connect a (for this
+   interface) individualy configured ipppd.
+
+--
+
+Q09: When I start the ipppd I only get error messages
+   from the i4l driver .. 
+
+A: When starting, the ipppd calls functions which may 
+   trigger a network packet. (e.g gethostbyname()).
+   Without the ipppd (at this moment, it is not
+   fully started) we can't handle this network request.
+   Try to configure hostnames necessary for the ipppd
+   in your local /etc/hosts file or in a way, that
+   your system can resolve it without using an
+   isdn/ippp network-interface.
+
+--
+
+Q10: I wanna use dynamic IP address assignment ... How 
+   must I configure the network device.
+
+A: At least you must have a routing, which forwards
+   a packet to the ippp network-interface to trigger
+   the dial-on-demand.
+   A default routing to the ippp-interface will work.
+   Now you must choose a dummy IP address for your
+   interface.
+   If for some reason you can't set the default
+   routing to the ippp interface, you may take any 
+   address of the subnet from which you expect your
+   dynamic IP number and set a 'network route' for
+   this subnet to the ippp interface.
+   To allow overriding of the dummy address you
+   must call the ipppd with the 'ipcp-accept-local' option.
+
+A: You must know, how the ipppd gets the addresses it wanna
+   configure. If you don't give any option, the ipppd
+   tries to negotiate the local host address!
+   With the option 'noipdefault' it requests an address
+   from the remote machine. With 'useifip' it gets the
+   addresses from the net interface. Or you set the addresse
+   on the option line with the <a.b.c.d:e.f.g.h> option.
+   Note: the IP address of the remote machine must be configured
+   locally or the remote machine must send it in an IPCP request.
+   If your side doesn't know the IP address after negotiation, it
+   closes the connection!
+   You must allow overriding of address with the 'ipcp-accept-*'
+   options, if you have set your own or the remote address 
+   explicitly.
+
+A: Maybe you try these options .. e.g:   
+
+    /sbin/ipppd :$REMOTE noipdefault /dev/ippp0
+
+   where REMOTE must be the address of the remote machine (the
+   machine, which gives you your address)
+
+--
+
+Q11: I can't connect. How can I check where the problem is.
+
+A: A good help log is the debug output from the ipppd...
+   Check whether you can find there:
+   - only a few LCP-conf-req SENT messages (less then 10)
+     and then a Term-REQ:
+     -> check whether your ISDN card is well configured
+        it seems, that your machine doesn't dial
+        (IRQ,IO,Proto, etc problems)
+        Configure your ISDN card to print debug messages and
+        check the /dev/isdnctrl output next time. There
+        you can see, whether there is activity on the card/line.
+   - there are at least a few RECV messages in the log:
+     -> fine: your card is dialing and your remote machine
+        tries to talk with you. Maybe only a missing 
+        authentification. Check your ipppd configuration again.
+   - the ipppd exits for some reason:
+     -> not good ... check /var/adm/syslog and /var/adm/daemon.
+        Could be a bug in the ipppd.
+
+--
+
+Q12: How can I reduce login delay?
+
+A: Log a login session ('debug' log) and check which options 
+  your remote side rejects. Next time configure your ipppd
+  to not negotiate these options. Another 'side effect' is, that
+  this increases redundancy. (e.g your remote side is buggy and
+  rejects options in a wrong way).