View Source: 3ComDualLinkPPPoE - Waikato Linux Users Group

Edit PageHistory Diff Info LikePages

When 3Com decided to build a PPPoE <-> ADSL modem - [3ComDualLink], they decided that conforming to the PPPoE [ RFC | http://www.faqs.org/rfcs/rfc2516.html ] was entirely too plain.  Instead of using boring ASSIGNED values for the [PPPoE] session and discovery protocols, they decided ones starting with 0x3c would be much more customer orientated!  So, instead of 0x8863 and 0x8864 for Discovery and Session packets respectively, they decided to use 0x3c12 and 0x3c13... insanity!

!User Mode
----

Luckily enough, rp-pppoe was kind enough to allow us to specifiy different frame headers.  So if you're using rp-pppoe just add "-f 3c12:3c13" to the pppoe command line.

From the [LinuxPPPoENotes] page, heres how pppd would run pppoe now:

 /usr/sbin/pppoe -p /var/run/pppoe.conf-adsl.pid.pppoe  -I eth0 -f 3c12:3c13 -U -m 1412 -T 80 -S ISP

!Kernel Mode
----

Unfortunately, things are not so simple in kernel mode.

I've made a diff you can apply to the ppp-2.4.2 tarball, or put it in the debian/patches directory and re-build the deb.
Here's the [ unified diff | http://www.wlug.org.nz/~james/060-pppoe-frame-opt.diff ].

Man, if only thats where it ended.  It seems that linux/if_ether.h has ..
 #define ETH_P_PPP_SES 0x8864
and the kernel module uses that!

But we can get around this (hackishly for now, hopefully someone will add an IOCTL to do this), by using the following [ patch | http://www.wlug.org.nz/~james/pppoe.diff ].

Now, you add the following lines to your /etc/ppp/peers/''myisp'' file, and you should have kernel mode pppoe:
 rp_pppoe_disc 3c12
 rp_pppoe_sess 3c13

Uncomment ''debug'' in that file, if you have any problems.

Good Luck

!FreeBSD
----

To use this modem with FreeBSD set
 sysctl net.graph.nonstandard_pppoe=1

After you have the ng_pppoe moduled loaded. Put it in /etc/sysctl.conf to make it persistent. For more information about using PPPoE in FreeBSD see the [handbook|http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/pppoe.html].

2 pages link to 3ComDualLinkPPPoE:

Last edited on Thursday, April 22, 2004 12:47:58 am by PhilMurray

Edit PageHistory Diff Info LikePages