Hi, I'm experiencing a pretty strange problem with kernel PPPoE on tap interfaces with a vanilla 2.6.20 kernel that prevents the PPP connection from being established:
Every PPPoE session packet (that is, LCP, since it never gets to a stage where any other session data is being exchanged) is delivered to pppd twice. This can be seen from pppd's logging messages when debugging is enabled, and strace confirmed that it indeed does read() the exact same data twice in a row from the same file descriptor - even though a tcpdump on the corresponding tap interface does show each packet only once. For confirming this, I used a program with a select() loop that simply moves packets unchanged and without reordering back and forth between a "real" ethernet interface in promiscuous mode and the tap interface used by pppd. What makes this even stranger, is, that the setup works perfectly (and only a single copy of packets is delivered to pppd) if I simply replace the tap interface in pppd's config with the "real" ethernet interface that the tap interface was previously bridged to (it's an ISA NE2K clone, BTW). Finally, it also works perfectly when I use userspace rp-pppoe through the tap interface. So far, I also confirmed that in kernel space, the call to ppp_input() in drivers/net/pppoe.c is executed as many times as pppd receives a packet, so the problem must be somewhere before that. Well, I'm gonna try to find out more - but if someone with some more knowledge of the involved kernel code would be willing to help with this in some way or another, that would certainly be appreciated ;-) - if you do need any additional information, let me know ... Florian - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
