IP addresses on Discovers

[Leger, Rita]

A colleague suggested that I post some more information, in hopes that
it might hit home with other users out there.  The STB that we are
trying to introduce uses WIN CE as its operating system.  

I also did a test of running only one DHCP server and I was still
receiving a different IP address on every reboot.  Also, I found an
error in the logs that indicated that the next available IP address is a
duplicate on the network but it then issues the same address on the next
Discover.  The binding states of the IP address when they are rebooted
are set to active.  Does the DHCP server look at the leases file to see
if there is an active IP address for the MAC requesting an IP address
before issuing a new IP address?  If not why do I have another version
of DHCP client consistently receiving the same IP address?  Also, what
do these duplicate errors mean?

Here is an example of the errors in the log files:

Apr 23 14:10:48 server-1 dhcpd: [ID XXXXX local7.info] DHCPDISCOVER from
00:19:a6:ab:95:a9 (CED0019A6AB95A9) via bge1
Apr 23 14:10:49 server-1 dhcpd: [ID XXXX local7.info] DHCPOFFER on
10.160.2.111 to 00:19:a6:ab:95:a9 (CED0019A6AB95A9) via
 bge1
Apr 23 14:10:49 server-1 dhcpd: [ID XXXX local7.error] uid lease
10.160.2.113 for client 00:19:a6:ab:95:a9 is duplicate on
 10.160/16
Apr 23 14:10:49 server-1 dhcpd: [ID XXXX local7.info] DHCPREQUEST for
10.160.2.111 (10.160.254.14) from 00:19:a6:ab:95:a9
(CED0019A6AB95A9) via bge1
Apr 23 14:10:49 server-1 dhcpd: [ID XXXX local7.info] DHCPACK on
10.160.2.111 to 00:19:a6:ab:95:a9 (CED0019A6AB95A9) via b
ge1
Apr 23 14:12:04 server-1 dhcpd: [ID XXXX local7.info] DHCPDISCOVER from
00:19:a6:ab:95:a9 via bge1
Apr 23 14:12:05 server-1 dhcpd: [ID XXXX local7.info] DHCPOFFER on
10.160.2.113 to 00:19:a6:ab:95:a9 via bge1
Apr 23 14:12:05 server-1 dhcpd: [ID XXXX local7.error] uid lease
10.160.2.115 for client 00:19:a6:ab:95:a9 is duplicate on
 10.160/16
Apr 23 14:12:05 server-1 dhcpd: [ID XXXX local7.info] DHCPREQUEST for
10.160.2.113 (10.160.254.14) from 00:19:a6:ab:95:a9
via bge1
Apr 23 14:12:05 server-1 dhcpd: [ID XXXX local7.info] DHCPACK on
10.160.2.113 to 00:19:a6:ab:95:a9 via bge1

Any suggestions would be greatly appreciated.

Rita

>We have been running ISC dhcp in a redundant failover configuration
here
>for the past 8 months with very good success. Up until now we have been
>running with only one model of Set top box but we are now trying to
>introduce a different model of STB. Our lease times are set to 24
hours.

 

>Once the first model of STB receives its IP address it retains the same
>IP address even on a reboot and an issue of another Discover regardless
>of which DHCP server fulfills the request.  Now with the different
model
>STB once it receives its IP address it does not always retain the same
>IP address on the next Discover.  If it receives its offer from the
>original DHCP server that it originally first received the IP address
>from, the DHCP server offers the same IP address again, but if the
other
>DHCP server fills the Discover it does not offer the same IP address
>again, it issues a different address.  Is there any way to force both
>servers to reissue the same IP address to a STB on a Discover?

 

Thanks,

Rita Leger

Design Specialist - Applications Infrastructure Engineering

Aliant Applications Engineering

Rita.Leger at aliant.ca <mailto:Rita.Leger at aliant.ca> 

(506) 694-3653