Multiple dhcrelay setup causing multiple duplicate DHCP requests

Thu Aug 12 03:44:27 UTC 2010

Hi guys,

I need some assistance with a multiple dhcrelay setup with failover dhcpd
servers.
The problem I'm getting is multiple duplicate dhcp requests being received
by the dhcpd servers (which is filling up the disk very quickly on the
server).

Here is the log from one of the dhcp servers showing the result:
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPREQUEST for 10.1.70.185 from
00:0c:29:42:f1:1b via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: DHCPACK on 10.1.70.185 to 00:0c:29:42:f1:1b
via 10.1.70.1
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.
Jul 30 11:56:31 alns0 dhcpd: bind update on 10.1.70.185 got ack from
dhcp-failover: xid mismatch.

The network is configured like this:

  [ dhcpd1 ]
       |
 eth0/vlan120
[ fw1/dhcrelay ]
     eth5
       |
     eth5
[ fw2/dhcrelay ]
 eth0/vlan120
       |
   [ dhcpd2 ]

The configuration on the dhcrelays is like this:

/usr/sbin/dhcrelay3 -q -i eth0 -i eth1 -i vlan1 -i vlan120 -i vlan140 -i
vlan150 -i vlan151 -i vlan170 dhcpd1 dhcpd2 (actually have IPs in here)

The versions used are (latest in Debian Lenny - stable release):
dhcp3-common            3.1.1-6+lenny4
dhcp3-relay             3.1.1-6+lenny4
dhcp3-server      3.1.1-6+lenny4

Any help is appreciated.

Cheers

Mike Hodgkinson
Support & Managed Services
Solnet Solutions Limited
Level 12, Solnet House
70 The Terrace, Wellington 6011, New Zealand
PO Box 397, Wellington 6140, New Zealand
DDI +64 4 462 5064, Mobile +64 21 754 339
Main +64 4 462 5000, Fax +64 4 462 5012

www.solnetsolutions.co.nz
A Solnet Group Company

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