>From the basic cHDLC information available and from my own testing,
sending all packets with the multicast address set is incorrect and a bug
in syncppp.
The multicast address is only used when the system thinks the upper layer
is sending a broadcast packet. Since we're generally not sending
broadcast packets there's no reason to be using the multicast address.
If you look closely btw, the 3600 is receiving the packet, recognizing it
as an IP packet even. It presumably discards it before it get's to the
forwarding stage.
Andrew
On Mon, 21 Feb 2000, Paul Fulghum wrote:
> I have a suggestion for syncppp (not directly related to this topic):
>
> I have encountered some Cisco routers (3600 series IOS 12.0 and 11.3) that
> refuse to recognize Cisco HDLC packets using the
> Cisco multicast address (0xf9). They work fine with the
> unicast address (0x09). A Cisco 1600 series (IOS 11.1) router accepts
> both, but always uses the unicast for responses.
>
> syncppp is hard coded to always use the multicast address.
> My suggestion (and how I am currently working) is to add a
> flag PP_UNICAST to allow the user to select the address.
> Default is not set so it behaves as before. If the flag is set then
> the unicast address is used.
>
> Another part of the suggestion is to add ioctl handling to
> set/get the syncppp flags, so the user can configure the
> existing keepalive setting (PP_KEEPALIVE) as well
> as the other settings (PP_UNICAST, PP_CISCO,PP_DEBUG).
> (and possibly move the ioctl constants to a header file in
> the include/linux directory)
>
> Any objections and/or comments?
>
> Paul Fulghum paulkf@microgate.com
> Microgate Corporation www.microgate.com
>
>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.rutgers.edu
> Please read the FAQ at http://www.tux.org/lkml/
>
--- Andrew Stanley-Jones | "It's kind of fun to do the impossible." http://www.ksirc.org/ | -- Walt Disney http://www.cban.com/ |- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Wed Feb 23 2000 - 21:00:28 EST