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On 4/3/2014 Denis Taranushin wrote:
<blockquote
cite="mid:mailman.34288.1396501201.20660.dhcp-users@lists.isc.org"
type="cite">
<pre wrap="">Date: Thu, 03 Apr 2014 10:59:47 +0600
From: Denis Taranushin <a moz-do-not-send="true" class="moz-txt-link-rfc2396E" href="mailto:tda@suttk.ru"><tda@suttk.ru></a>
To: <a moz-do-not-send="true" class="moz-txt-link-abbreviated" href="mailto:dhcp-users@lists.isc.org">dhcp-users@lists.isc.org</a>
Subject: DHCP server answers with delay
Message-ID: <a moz-do-not-send="true" class="moz-txt-link-rfc2396E" href="mailto:533CEAC3.4020801@suttk.ru"><533CEAC3.4020801@suttk.ru></a>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Hello, All
We have trouble with DHCP. namely the DHCP server answers with delay.
Sometimes the Server answers on 2th or 3th "Discover"
In this time a Client sends some "Discover"s and the server answers each
of them.
So in final the Client receives 2-3 "Offers" of IP, and accepts the last
one.
It makes impossible to work billing because the billing does session by
the first "Discover" and the second and each next will be forbidden.
Why the server answers in 4 secs after the first "Discover"?
tcpdump on server:
1335 2014-04-02 11:04:41.173969 10.0.0.1 10.0.0.13 DHCP 378 DHCP
Discover - Transaction ID 0x21fe4bf0
2344 2014-04-02 11:04:44.168945 10.0.0.1 10.0.0.13 DHCP 378 DHCP
Discover - Transaction ID 0x21fe4bf0
2554 2014-04-02 11:04:45.171448 10.0.0.13 10.0.0.1 DHCP 369 DHCP Offer
- Transaction ID 0x21fe4bf0
2559 2014-04-02 11:04:45.196749 10.0.0.1 10.0.0.13 DHCP 402 DHCP Request
- Transaction ID 0x21fe4bf0
2562 2014-04-02 11:04:45.199567 10.0.0.13 10.0.0.1 DHCP 369 DHCP ACK
- Transaction ID 0x21fe4bf0
3813 2014-04-02 11:04:48.714916 10.0.0.1 10.0.0.13 DHCP 373 DHCP Inform
- Transaction ID 0x8b4c15cc
3819 2014-04-02 11:04:48.719283 10.0.0.13 10.0.0.247 DHCP 342 DHCP ACK
- Transaction ID 0x8b4c15cc
Unfortunately I can't provide the config because it is enormous.
Some ideas?</pre>
</blockquote>
<font face="Courier New"><small>Could this be possibly related to a
"ping-check", assuming that it is enabled, to the client? I have
some clients that don't follow the spec and hold on to their
current IP address when doing a discover, so the ping check is
positive (server can ping the client IP address in the lease
database), so the server abandons the lease, and during which
time, the client sends multiple discovers (maybe check the logs
for abandoned leases?) -- just a WAG...<br>
<br>
Pete C.<br>
</small><br>
</font>
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