isc dhcpd and cisco router Post: 302445760

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Special Forums IP Networking isc dhcpd and cisco router Post 302445760 by closedown on Monday 16th of August 2010 08:21:14 PM

08-16-2010

Registered User

isc dhcpd and cisco router

Hello all,

I have set up dhcpd on a linux box for serving subnets on multiple vlans configured on a Cisco 6500 with ip helper of the dhcp server. Servers get dhcp leases just fine, however, some machines lose their connection for reboot or what not and I can not get their lease back even though it expires in 7 days without a reboot. It appears that the server is sending out REQUESTS to the proper gateway, but also BROADCASTS to the other vlan gateways. Kind of odd. Has anyone experienced this?

## This is the correct network and vlan it should be hitting on 10.14.6.:

Aug 10 23:22:30 dhcpd1 dhcpd: DHCPREQUEST for 10.14.6.212 (10.14.16.111) from 00:04:4b:04:45:23 via 10.14.6.1
Aug 10 23:22:30 dhcpd1 dhcpd: DHCPACK on 10.14.6.212 to 00:04:4b:04:45:23 (server10) via 10.14.6.1

## However, it goes on to what it seems like sending out a unicast packet to all other vlan gateways and then it breaks:

Aug 10 23:22:30 dhcpd1 dhcpd: DHCPREQUEST for 10.14.6.212 (10.14.16.111) from 00:04:4b:04:45:23 (server10) via 10.14.12.1: wrong network.
Aug 10 23:22:30 dhcpd1 dhcpd: DHCPNAK on 10.14.6.212 to 00:04:4b:04:45:23 via 10.14.12.1
Aug 10 23:22:30 dhcpd1 dhcpd: DHCPREQUEST for 10.14.6.212 (10.14.16.111) from 00:04:4b:04:45:23 (server10) via 10.14.4.1: wrong network.
Aug 10 23:22:30 dhcpd1 dhcpd: DHCPNAK on 10.14.6.212 to 00:04:4b:04:45:23 via 10.14.4.1
Aug 10 23:22:30 dhcpd1 dhcpd: DHCPREQUEST for 10.14.6.212 (10.14.16.111) from 00:04:4b:04:45:23 (server10) via 10.14.2.1: wrong network.
Aug 10 23:22:30 dhcpd1 dhcpd: DHCPNAK on 10.14.6.212 to 00:04:4b:04:45:23 via 10.14.2.1
Aug 10 23:22:30 dhcpd1 dhcpd: DHCPREQUEST for 10.14.6.212 (10.14.16.111) from 00:04:4b:04:45:23 (server10) via 10.14.10.1: wrong network.
Aug 10 23:22:30 dhcpd1 dhcpd: DHCPNAK on 10.14.6.212 to 00:04:4b:04:45:23 via 10.14.10.1
Aug 10 23:22:30 dhcpd1 dhcpd: DHCPREQUEST for 10.14.6.212 (10.14.16.111) from 00:04:4b:04:45:23 (server10) via 10.14.145.1: wrong network

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LEARN ABOUT FREEBSD

dhclient.leases

DHCLIENT.LEASES(5)					      BSD File Formats Manual						DHCLIENT.LEASES(5)

NAME

     dhclient.leases -- DHCP client lease database

DESCRIPTION

     The Internet Software Consortium DHCP client keeps a persistent database of leases that it has acquired that are still valid.  The database
     is a free-form ASCII file containing one valid declaration per lease.  If more than one declaration appears for a given lease, the last one
     in the file is used.  The file is written as a log, so this is not an unusual occurrence.

     The lease file is named dhclient.leases.IFNAME, where IFNAME represents the network interface the DHCP client acquired the lease on.  For
     example, if dhclient(8) is configured for the em0 network device, the lease file will be named dhclient.leases.em0.

     The format of the lease declarations is described in dhclient.conf(5).

FILES

     /var/db/dhclient.leases.IFNAME  Current lease file.

SEE ALSO

     dhclient.conf(5), dhcp-options(5), dhcpd.conf(5), dhclient(8), dhcpd(8)

     RFC 2132, RFC 2131.

AUTHORS

     The dhclient(8) utility was written by Ted Lemon <mellon@vix.com> under a contract with Vixie Labs.

     The current implementation was reworked by Henning Brauer <henning@openbsd.org>.

BSD
								  January 1, 1997							       BSD