Re: [ECOS] Low network throughput using DHCP

["Xavier" <xavierwang at ms19 dot url dot com dot tw>]

Thanks Andrew.

There was only one NIC in my system. And there was no DHCP
packet observed. The DHCP lease management thread had no
activity either.

By skimming over the captured packets of tcp_echo, nothing seems
to be wrong for the DHCP version. An obvious difference is that
there are about 700 packets per second for the static IP version,
but only about 100 packets per second for the DHCP version.

Any help will be greatly appreciated.

Regards,
Xavier


----- Original Message ----- 
From: "Andrew Lunn" <andrew.lunn@ascom.ch>
To: "Xavier" <xavierwang@ms19.url.com.tw>
Cc: <ecos-discuss@sources.redhat.com>
Sent: Friday, August 09, 2002 5:46 PM
Subject: Re: [ECOS] Low network throughput using DHCP


On Fri, Aug 09, 2002 at 05:37:35PM +0800, Xavier wrote:
> Hi,
> 
> Had someone experienced that the networking performance
> dropped down dramatically while using DHCP? My CPU
> is a 50MHz MIPS, and the result of tcp_echo is around
> 4Mbps when using static IP, but dropped down to about
> 0.4Mbps when using DHCP. Another aspect is that the
> tftp_client_test failed almost every times to get a file of
> 20K bytes via TFTP when using DHCP, but the same test
> program worked well by using static IP.
> 
> Any suggestions?

Check to see if there any DHCP operations going on while the data
transfer is happening. The DHCP client does some strange things with
the interface to ensure that the DHCP messages go out the correct
interface when you have more than one. These could be affecting
performance, but does seem unlikely to be that bad.

        Andrew


-- 
Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss