diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/isdn/syncPPP.FAQ |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
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1 | simple isdn4linux PPP FAQ .. to be continued .. not 'debugged' | ||
2 | ------------------------------------------------------------------- | ||
3 | |||
4 | Q01: what's pppd, ipppd, syncPPP, asyncPPP ?? | ||
5 | Q02: error message "this system lacks PPP support" | ||
6 | Q03: strange information using 'ifconfig' | ||
7 | Q04: MPPP?? What's that and how can I use it ... | ||
8 | Q05: I tried MPPP but it doesn't work | ||
9 | Q06: can I use asynchronous PPP encapsulation with network devices | ||
10 | Q07: A SunISDN machine can't connect to my i4l system | ||
11 | Q08: I wanna talk to several machines, which need different configs | ||
12 | Q09: Starting the ipppd, I get only error messages from i4l | ||
13 | Q10: I wanna use dynamic IP address assignment | ||
14 | Q11: I can't connect. How can I check where the problem is. | ||
15 | Q12: How can I reduce login delay? | ||
16 | |||
17 | ------------------------------------------------------------------- | ||
18 | |||
19 | Q01: pppd, ipppd, syncPPP, asyncPPP .. what is that ? | ||
20 | what should I use? | ||
21 | A: The pppd is for asynchronous PPP .. asynchronous means | ||
22 | here, the framing is character based. (e.g when | ||
23 | using ttyI* or tty* devices) | ||
24 | |||
25 | The ipppd handles PPP packets coming in HDLC | ||
26 | frames (bit based protocol) ... The PPP driver | ||
27 | in isdn4linux pushes all IP packets direct | ||
28 | to the network layer and all PPP protocol | ||
29 | frames to the /dev/ippp* device. | ||
30 | So, the ipppd is a simple external network | ||
31 | protocol handler. | ||
32 | |||
33 | If you login into a remote machine using the | ||
34 | /dev/ttyI* devices and then enable PPP on the | ||
35 | remote terminal server -> use the 'old' pppd | ||
36 | |||
37 | If your remote side immediately starts to send | ||
38 | frames ... you probably connect to a | ||
39 | syncPPP machine .. use the network device part | ||
40 | of isdn4linux with the 'syncppp' encapsulation | ||
41 | and make sure, that the ipppd is running and | ||
42 | connected to at least one /dev/ippp*. Check the | ||
43 | isdn4linux manual on how to configure a network device. | ||
44 | |||
45 | -- | ||
46 | |||
47 | Q02: when I start the ipppd .. I only get the | ||
48 | error message "this system lacks PPP support" | ||
49 | A: check that at least the device 'ippp0' exists. | ||
50 | (you can check this e.g with the program 'ifconfig') | ||
51 | The ipppd NEEDS this device under THIS name .. | ||
52 | If this device doesn't exists, use: | ||
53 | isdnctrl addif ippp0 | ||
54 | isdnctrl encap ippp0 syncppp | ||
55 | ... (see isdn4linux doc for more) ... | ||
56 | A: Maybe you have compiled the ipppd with another | ||
57 | kernel source tree than the kernel you currently | ||
58 | run ... | ||
59 | |||
60 | -- | ||
61 | |||
62 | Q03: when I list the netdevices with ifconfig I see, that | ||
63 | my ISDN interface has a HWaddr and IRQ=0 and Base | ||
64 | address = 0 | ||
65 | A: The device is a fake ethernet device .. ignore IRQ and baseaddr | ||
66 | You need the HWaddr only for ethernet encapsulation. | ||
67 | |||
68 | -- | ||
69 | |||
70 | Q04: MPPP?? What's that and how can I use it ... | ||
71 | |||
72 | A: MPPP or MP or MPP (Warning: MP is also an | ||
73 | acronym for 'Multi Processor') stands for | ||
74 | Multi Point to Point and means bundling | ||
75 | of several channels to one logical stream. | ||
76 | To enable MPPP negotiation you must call the | ||
77 | ipppd with the '+mp' option. | ||
78 | You must also configure a slave device for | ||
79 | every additional channel. (see the i4l manual | ||
80 | for more) | ||
81 | To use channel bundling you must first activate | ||
82 | the 'master' or initial call. Now you can add | ||
83 | the slave channels with the command: | ||
84 | isdnctrl addlink <device> | ||
85 | e.g: | ||
86 | isdnctrl addlink ippp0 | ||
87 | This is different from other encapsulations of | ||
88 | isdn4linux! With syncPPP, there is no automatic | ||
89 | activation of slave devices. | ||
90 | |||
91 | -- | ||
92 | |||
93 | Q05: I tried MPPP but it doesn't work .. the ipppd | ||
94 | writes in the debug log something like: | ||
95 | .. rcvd [0][proto=0x3d] c0 00 00 00 80 fd 01 01 00 0a ... | ||
96 | .. sent [0][LCP ProtRej id=0x2 00 3d c0 00 00 00 80 fd 01 ... | ||
97 | |||
98 | A: you forgot to compile MPPP/RFC1717 support into the | ||
99 | ISDN Subsystem. Recompile with this option enabled. | ||
100 | |||
101 | -- | ||
102 | |||
103 | Q06: can I use asynchronous PPP encapsulation | ||
104 | over the network interface of isdn4linux .. | ||
105 | |||
106 | A: No .. that's not possible .. Use the standard | ||
107 | PPP package over the /dev/ttyI* devices. You | ||
108 | must not use the ipppd for this. | ||
109 | |||
110 | -- | ||
111 | |||
112 | Q07: A SunISDN machine tries to connect my i4l system, | ||
113 | which doesn't work. | ||
114 | Checking the debug log I just saw garbage like: | ||
115 | !![ ... fill in the line ... ]!! | ||
116 | |||
117 | A: The Sun tries to talk asynchronous PPP ... i4l | ||
118 | can't understand this ... try to use the ttyI* | ||
119 | devices with the standard PPP/pppd package | ||
120 | |||
121 | A: (from Alexanter Strauss: ) | ||
122 | !![ ... fill in mail ]!! | ||
123 | |||
124 | -- | ||
125 | |||
126 | Q08: I wanna talk to remote machines, which need | ||
127 | a different configuration. The only way | ||
128 | I found to do this is to kill the ipppd and | ||
129 | start a new one with another config to connect | ||
130 | to the second machine. | ||
131 | |||
132 | A: you must bind a network interface explicitly to | ||
133 | an ippp device, where you can connect a (for this | ||
134 | interface) individually configured ipppd. | ||
135 | |||
136 | -- | ||
137 | |||
138 | Q09: When I start the ipppd I only get error messages | ||
139 | from the i4l driver .. | ||
140 | |||
141 | A: When starting, the ipppd calls functions which may | ||
142 | trigger a network packet. (e.g gethostbyname()). | ||
143 | Without the ipppd (at this moment, it is not | ||
144 | fully started) we can't handle this network request. | ||
145 | Try to configure hostnames necessary for the ipppd | ||
146 | in your local /etc/hosts file or in a way, that | ||
147 | your system can resolve it without using an | ||
148 | isdn/ippp network-interface. | ||
149 | |||
150 | -- | ||
151 | |||
152 | Q10: I wanna use dynamic IP address assignment ... How | ||
153 | must I configure the network device. | ||
154 | |||
155 | A: At least you must have a route which forwards | ||
156 | a packet to the ippp network-interface to trigger | ||
157 | the dial-on-demand. | ||
158 | A default route to the ippp-interface will work. | ||
159 | Now you must choose a dummy IP address for your | ||
160 | interface. | ||
161 | If for some reason you can't set the default | ||
162 | route to the ippp interface, you may take any | ||
163 | address of the subnet from which you expect your | ||
164 | dynamic IP number and set a 'network route' for | ||
165 | this subnet to the ippp interface. | ||
166 | To allow overriding of the dummy address you | ||
167 | must call the ipppd with the 'ipcp-accept-local' option. | ||
168 | |||
169 | A: You must know, how the ipppd gets the addresses it wanna | ||
170 | configure. If you don't give any option, the ipppd | ||
171 | tries to negotiate the local host address! | ||
172 | With the option 'noipdefault' it requests an address | ||
173 | from the remote machine. With 'useifip' it gets the | ||
174 | addresses from the net interface. Or you set the address | ||
175 | on the option line with the <a.b.c.d:e.f.g.h> option. | ||
176 | Note: the IP address of the remote machine must be configured | ||
177 | locally or the remote machine must send it in an IPCP request. | ||
178 | If your side doesn't know the IP address after negotiation, it | ||
179 | closes the connection! | ||
180 | You must allow overriding of address with the 'ipcp-accept-*' | ||
181 | options, if you have set your own or the remote address | ||
182 | explicitly. | ||
183 | |||
184 | A: Maybe you try these options .. e.g: | ||
185 | |||
186 | /sbin/ipppd :$REMOTE noipdefault /dev/ippp0 | ||
187 | |||
188 | where REMOTE must be the address of the remote machine (the | ||
189 | machine, which gives you your address) | ||
190 | |||
191 | -- | ||
192 | |||
193 | Q11: I can't connect. How can I check where the problem is. | ||
194 | |||
195 | A: A good help log is the debug output from the ipppd... | ||
196 | Check whether you can find there: | ||
197 | - only a few LCP-conf-req SENT messages (less then 10) | ||
198 | and then a Term-REQ: | ||
199 | -> check whether your ISDN card is well configured | ||
200 | it seems, that your machine doesn't dial | ||
201 | (IRQ,IO,Proto, etc problems) | ||
202 | Configure your ISDN card to print debug messages and | ||
203 | check the /dev/isdnctrl output next time. There | ||
204 | you can see, whether there is activity on the card/line. | ||
205 | - there are at least a few RECV messages in the log: | ||
206 | -> fine: your card is dialing and your remote machine | ||
207 | tries to talk with you. Maybe only a missing | ||
208 | authentication. Check your ipppd configuration again. | ||
209 | - the ipppd exits for some reason: | ||
210 | -> not good ... check /var/adm/syslog and /var/adm/daemon. | ||
211 | Could be a bug in the ipppd. | ||
212 | |||
213 | -- | ||
214 | |||
215 | Q12: How can I reduce login delay? | ||
216 | |||
217 | A: Log a login session ('debug' log) and check which options | ||
218 | your remote side rejects. Next time configure your ipppd | ||
219 | to not negotiate these options. Another 'side effect' is, that | ||
220 | this increases redundancy. (e.g your remote side is buggy and | ||
221 | rejects options in a wrong way). | ||
222 | |||
223 | |||
224 | |||