OK Ross I think I understand now.

I did not realise before that the ifconfig you posted was from the Netcomm 
box. I thought it was from the Mandrake mail server.  It is the mail server 
on which I was suggesting reducing the MTU.

In any case I think I know what the problem is, and why you are getting so 
many collisions on the Ethernet.

I think you have an auto-negotiation problem on the Ethernet between the 
Netcomm box, and the Mandrake box.
One or both of them have configured themselves for full duplex operation, but 
the cable/hub you are using is only capable of half duplex. So whenever a 
data packet collides with an acknowledgment you get a retransmission and the 
whole thing slows to a crawl.

The solution is to either replace your Ethernet hub with a full duplex switch  
(the unbranded ones are real cheap now), or else to force your Ethernet 
interfaces to half duplex.

There should be a utility on your Mandrake system, (and hopefully the Netcomm 
aslso) called mii-tool Just type mii-tool and you will see the status of your 
Ethernets
[root@Derek derek]# mii-tool
eth0: negotiated 100baseTx-FD flow-control, link ok


mii-tool -F 100baseTx-HD eth0

will for example force 100M Ethernet Half duplex.  See man mii-tool for 
details.

Also do not forget to set your Windows boxes to Half duplex also :)

HTH

derek


On Sunday 02 Feb 2003 2:19 am, Ross Slade wrote:
> -----------------------------------------------------------
> eth0      Link encap:Ethernet  HWaddr 00:60:64:02:32:12
>           inet addr:192.168.1.1  Bcast:192.168.1.255  Mask:255.255.255.0
>           UP BROADCAST RUNNING MULTICAST  MTU:552  Metric:1
>           RX packets:513 errors:0 dropped:880 overruns:0 frame:205
>           TX packets:469 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:1
>           Interrupt:3 Base address:0x300
>
> lo        Link encap:Local Loopback
>           inet addr:127.0.0.1  Bcast:127.255.255.255  Mask:255.0.0.0
>           UP BROADCAST LOOPBACK RUNNING  MTU:3584  Metric:1
>           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0
>
> ppp0      Link encap:Point-to-Point Protocol
>           inet addr:203.14.156.30  P-t-P:203.14.156.2  Mask:255.255.255.0
>           UP POINTOPOINT RUNNING  MTU:552  Metric:1
>           RX packets:380 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:390 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0
>           Memory:325036-32549a
> -----------------------------------------------------------
>
>
>
>
> ----- Original Message -----
> From: Derek Jennings <[EMAIL PROTECTED]>
>
> > I do not understand why you have a ppp0 and sl0 interface up? Do you have
>
> a
>
> > dial up connection, or some other interface active? Or is this how pppoe
>
> is
>
> > configured?  The ppp0 interface seems to be in use. Could it be this is
>
> the
>
> > one you need to reduce the MTU on?
> >
> > You could also try a figure less than 1480 (I got that off a Windows XP
>
> help
>
> > site)
>
> I don't know, it's just however Netcomm set it up...ppp0 is my internet
> connection (31.6k)
>
> Above is what ifconfig reports now - an mtu of 576 seems common, but
> doesn't help with my problem. Any idea of a possible cause of the dropped
> RX packets and "collisions"?
>
> thanks, Ross
>
>
>
> ---
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