On 1 Sep 2002, Russell McManus wrote:

> I've got 1.5.2 installed on a powermac 7300.  Most things are working
> beautifully, but I seem to be getting very slow downloads.  I suspect
> that the problem is that the mc0 interface is simplex.

Nope. That speed is REALLY slow, and something is wrong, but SIMPLEX isn't
it. Rummaging around in include files (/usr/include/net/if.h to be exact)
we find:

#define IFF_SIMPLEX     0x0800          /* can't hear own transmissions */

That tells the Ethernet system to fake a packet reception when we send a
packet that we really want to hear (like a broadcast packet).

> /export/russe 2$ ifconfig  mc0
> ifconfig  mc0
> mc0: flags=8863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>         address: 00:05:02:ce:73:66
>         media: Ethernet manual
>         inet 192.168.1.3 netmask 0xffffff00 broadcast 192.168.1.255
>         inet6 fe80::205:2ff:fece:7366%mc0 prefixlen 64 scopeid 0x1
>
> The machine is behind a Linksys firewall/router.  I suspect that the
> router is not smart enough to do the right thing when a simplex client
> is attached.  Does anyone on the list have any ideas on how to debug
> the problem?

Try ftp'ing to the i386 box, and see how that does.

Also, try checking the cable out. I'm trying to think of the other things
folks have seen that give such horrid performance.

Take care,

Bill