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Documentation / networking / README.sb1000


Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.

1	sb1000 is a module network device driver for the General Instrument (also known
2	as NextLevel) SURFboard1000 internal cable modem board.  This is an ISA card
3	which is used by a number of cable TV companies to provide cable modem access.
4	It's a one-way downstream-only cable modem, meaning that your upstream net link
5	is provided by your regular phone modem.
6	
7	This driver was written by Franco Venturi <fventuri@mediaone.net>.  He deserves
8	a great deal of thanks for this wonderful piece of code!
9	
10	-----------------------------------------------------------------------------
11	
12	Support for this device is now a part of the standard Linux kernel.  The
13	driver source code file is drivers/net/sb1000.c.  In addition to this
14	you will need:
15	
16	1.) The "cmconfig" program.  This is a utility which supplements "ifconfig"
17	to configure the cable modem and network interface (usually called "cm0");
18	and
19	
20	2.) Several PPP scripts which live in /etc/ppp to make connecting via your
21	cable modem easy.
22	
23	   These utilities can be obtained from:
24	
25	      http://www.jacksonville.net/~fventuri/
26	
27	   in Franco's original source code distribution .tar.gz file.  Support for
28	   the sb1000 driver can be found at:
29	
30	      http://web.archive.org/web/*/http://home.adelphia.net/~siglercm/sb1000.html
31	      http://web.archive.org/web/*/http://linuxpower.cx/~cable/
32	
33	   along with these utilities.
34	
35	3.) The standard isapnp tools.  These are necessary to configure your SB1000
36	card at boot time (or afterwards by hand) since it's a PnP card.
37	
38	   If you don't have these installed as a standard part of your Linux
39	   distribution, you can find them at:
40	
41	      http://www.roestock.demon.co.uk/isapnptools/
42	
43	   or check your Linux distribution binary CD or their web site.  For help with
44	   isapnp, pnpdump, or /etc/isapnp.conf, go to:
45	
46	      http://www.roestock.demon.co.uk/isapnptools/isapnpfaq.html
47	
48	-----------------------------------------------------------------------------
49	
50	To make the SB1000 card work, follow these steps:
51	
52	1.) Run `make config', or `make menuconfig', or `make xconfig', whichever
53	you prefer, in the top kernel tree directory to set up your kernel
54	configuration.  Make sure to say "Y" to "Prompt for development drivers"
55	and to say "M" to the sb1000 driver.  Also say "Y" or "M" to all the standard
56	networking questions to get TCP/IP and PPP networking support.
57	
58	2.) *BEFORE* you build the kernel, edit drivers/net/sb1000.c.  Make sure
59	to redefine the value of READ_DATA_PORT to match the I/O address used
60	by isapnp to access your PnP cards.  This is the value of READPORT in
61	/etc/isapnp.conf or given by the output of pnpdump.
62	
63	3.) Build and install the kernel and modules as usual.
64	
65	4.) Boot your new kernel following the usual procedures.
66	
67	5.) Set up to configure the new SB1000 PnP card by capturing the output
68	of "pnpdump" to a file and editing this file to set the correct I/O ports,
69	IRQ, and DMA settings for all your PnP cards.  Make sure none of the settings
70	conflict with one another.  Then test this configuration by running the
71	"isapnp" command with your new config file as the input.  Check for
72	errors and fix as necessary.  (As an aside, I use I/O ports 0x110 and
73	0x310 and IRQ 11 for my SB1000 card and these work well for me.  YMMV.)
74	Then save the finished config file as /etc/isapnp.conf for proper configuration
75	on subsequent reboots.
76	
77	6.) Download the original file sb1000-1.1.2.tar.gz from Franco's site or one of
78	the others referenced above.  As root, unpack it into a temporary directory and
79	do a `make cmconfig' and then `install -c cmconfig /usr/local/sbin'.  Don't do
80	`make install' because it expects to find all the utilities built and ready for
81	installation, not just cmconfig.
82	
83	7.) As root, copy all the files under the ppp/ subdirectory in Franco's
84	tar file into /etc/ppp, being careful not to overwrite any files that are
85	already in there.  Then modify ppp@gi-on to set the correct login name,
86	phone number, and frequency for the cable modem.  Also edit pap-secrets
87	to specify your login name and password and any site-specific information
88	you need.
89	
90	8.) Be sure to modify /etc/ppp/firewall to use ipchains instead of
91	the older ipfwadm commands from the 2.0.x kernels.  There's a neat utility to
92	convert ipfwadm commands to ipchains commands:
93	
94	   http://users.dhp.com/~whisper/ipfwadm2ipchains/
95	
96	You may also wish to modify the firewall script to implement a different
97	firewalling scheme.
98	
99	9.) Start the PPP connection via the script /etc/ppp/ppp@gi-on.  You must be
100	root to do this.  It's better to use a utility like sudo to execute
101	frequently used commands like this with root permissions if possible.  If you
102	connect successfully the cable modem interface will come up and you'll see a
103	driver message like this at the console:
104	
105	         cm0: sb1000 at (0x110,0x310), csn 1, S/N 0x2a0d16d8, IRQ 11.
106	         sb1000.c:v1.1.2 6/01/98 (fventuri@mediaone.net)
107	
108	The "ifconfig" command should show two new interfaces, ppp0 and cm0.
109	The command "cmconfig cm0" will give you information about the cable modem
110	interface.
111	
112	10.) Try pinging a site via `ping -c 5 www.yahoo.com', for example.  You should
113	see packets received.
114	
115	11.) If you can't get site names (like www.yahoo.com) to resolve into
116	IP addresses (like 204.71.200.67), be sure your /etc/resolv.conf file
117	has no syntax errors and has the right nameserver IP addresses in it.
118	If this doesn't help, try something like `ping -c 5 204.71.200.67' to
119	see if the networking is running but the DNS resolution is where the
120	problem lies.
121	
122	12.) If you still have problems, go to the support web sites mentioned above
123	and read the information and documentation there.
124	
125	-----------------------------------------------------------------------------
126	
127	Common problems:
128	
129	1.) Packets go out on the ppp0 interface but don't come back on the cm0
130	interface.  It looks like I'm connected but I can't even ping any
131	numerical IP addresses.  (This happens predominantly on Debian systems due
132	to a default boot-time configuration script.)
133	
134	Solution -- As root `echo 0 > /proc/sys/net/ipv4/conf/cm0/rp_filter' so it
135	can share the same IP address as the ppp0 interface.  Note that this
136	command should probably be added to the /etc/ppp/cablemodem script
137	*right*between* the "/sbin/ifconfig" and "/sbin/cmconfig" commands.
138	You may need to do this to /proc/sys/net/ipv4/conf/ppp0/rp_filter as well.
139	If you do this to /proc/sys/net/ipv4/conf/default/rp_filter on each reboot
140	(in rc.local or some such) then any interfaces can share the same IP
141	addresses.
142	
143	2.) I get "unresolved symbol" error messages on executing `insmod sb1000.o'.
144	
145	Solution -- You probably have a non-matching kernel source tree and
146	/usr/include/linux and /usr/include/asm header files.  Make sure you
147	install the correct versions of the header files in these two directories.
148	Then rebuild and reinstall the kernel.
149	
150	3.) When isapnp runs it reports an error, and my SB1000 card isn't working.
151	
152	Solution -- There's a problem with later versions of isapnp using the "(CHECK)"
153	option in the lines that allocate the two I/O addresses for the SB1000 card.
154	This first popped up on RH 6.0.  Delete "(CHECK)" for the SB1000 I/O addresses.
155	Make sure they don't conflict with any other pieces of hardware first!  Then
156	rerun isapnp and go from there.
157	
158	4.) I can't execute the /etc/ppp/ppp@gi-on file.
159	
160	Solution -- As root do `chmod ug+x /etc/ppp/ppp@gi-on'.
161	
162	5.) The firewall script isn't working (with 2.2.x and higher kernels).
163	
164	Solution -- Use the ipfwadm2ipchains script referenced above to convert the
165	/etc/ppp/firewall script from the deprecated ipfwadm commands to ipchains.
166	
167	6.) I'm getting *tons* of firewall deny messages in the /var/kern.log,
168	/var/messages, and/or /var/syslog files, and they're filling up my /var
169	partition!!!
170	
171	Solution -- First, tell your ISP that you're receiving DoS (Denial of Service)
172	and/or portscanning (UDP connection attempts) attacks!  Look over the deny
173	messages to figure out what the attack is and where it's coming from.  Next,
174	edit /etc/ppp/cablemodem and make sure the ",nobroadcast" option is turned on
175	to the "cmconfig" command (uncomment that line).  If you're not receiving these
176	denied packets on your broadcast interface (IP address xxx.yyy.zzz.255
177	typically), then someone is attacking your machine in particular.  Be careful
178	out there....
179	
180	7.) Everything seems to work fine but my computer locks up after a while
181	(and typically during a lengthy download through the cable modem)!
182	
183	Solution -- You may need to add a short delay in the driver to 'slow down' the
184	SURFboard because your PC might not be able to keep up with the transfer rate
185	of the SB1000. To do this, it's probably best to download Franco's
186	sb1000-1.1.2.tar.gz archive and build and install sb1000.o manually.  You'll
187	want to edit the 'Makefile' and look for the 'SB1000_DELAY'
188	define.  Uncomment those 'CFLAGS' lines (and comment out the default ones)
189	and try setting the delay to something like 60 microseconds with:
190	'-DSB1000_DELAY=60'.  Then do `make' and as root `make install' and try
191	it out.  If it still doesn't work or you like playing with the driver, you may
192	try other numbers.  Remember though that the higher the delay, the slower the
193	driver (which slows down the rest of the PC too when it is actively
194	used). Thanks to Ed Daiga for this tip!
195	
196	-----------------------------------------------------------------------------
197	
198	Credits:  This README came from Franco Venturi's original README file which is
199	still supplied with his driver .tar.gz archive.  I and all other sb1000 users
200	owe Franco a tremendous "Thank you!"  Additional thanks goes to Carl Patten
201	and Ralph Bonnell who are now managing the Linux SB1000 web site, and to
202	the SB1000 users who reported and helped debug the common problems listed
203	above.
204	
205	
206						Clemmitt Sigler
207						csigler@vt.edu
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