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Re: BOOTP/DHCP delay question
- From: Andrew Lunn <andrew at lunn dot ch>
- To: Ilko Iliev <iliev at caretec dot at>
- Cc: ecos-discuss at sources dot redhat dot com
- Date: Mon, 31 Jan 2005 23:26:18 +0100
- Subject: Re: [ECOS] BOOTP/DHCP delay question
- References: <41FE65BE.3080505@caretec.at>
On Mon, Jan 31, 2005 at 06:07:10PM +0100, Ilko Iliev wrote:
> Hi,
> I use BOOTP and DHCP to configure my target IP, in both cases this
> process takes about 5 secs.
> So the questions are:
> 1. What is the purpose of this delay?
> 2. Can this be made immediately, i.e. not waiting for a timeout?
Look at the packets being transfered. I've seen a few different things
happen:
1) The dhcp server allocates an IP address and then sends out an ARP
for that address to see if anybody else is already using it. It then
waits a couple of seconds to see if anybody replies to the ARP before
giving the IP address to the dhcp client.
2) The dhcp client code passes the first packet to the ethernet device
before it is fully initialised. The ethernet device then drops the
packet. Some time later the dhcp client does a retry which does make
it out onto the wire.
It could be one of these is happening.
Andrew
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