BAD ADDRESS and IP Conflicts on a 50/50 DHCP split server setup

setup:

2x dhcp servers (10.10.10.10 & 10.10.10.11) 50/50 split of a distribution: 10.10.10.150-10.10.11.254. each has exclusion of 50% of distribution doesn't on lap on 1 another. setup created using windows 2008 r2 dhcp wizard's split-scope , follows kb: http://support.microsoft.com/kb/2005980

we have (up until created reservations) no issues dhcp (it worked). reservations our workstations (each server has same reservations) getting ip conflicts on 1 device day (the leases 1 day). we don't have delay on either server. each server there additional 50 or ips not set reservations in distribution list.

watching dhcp traffic see both dhcp servers answering dhcp request same ip 10.10.10.154 client confirms request replying same info, dhcp server ack client dhcp decline , prints on screen there ip conflict.

the way past remove bad address reservation in dhcp scope both servers , let them choice random ip. have confirmed nothing exists on 10.10.10.154 ip , no other leases set ip address on each server.

below basic output of such transaction (i can dump more if need be):

no. time source destination protocol length info
1 0.000000 0.0.0.0 255.255.255.255 dhcp 342 dhcp discover - transaction id 0xf5bfe34d

frame 1: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits)
ethernet ii, src: apple_46:43:43 (00:1f:f3:46:43:43), dst: broadcast (ff:ff:ff:ff:ff:ff)
internet protocol version 4, src: 0.0.0.0 (0.0.0.0), dst: 255.255.255.255 (255.255.255.255)
user datagram protocol, src port: bootpc (68), dst port: bootps (67)
bootstrap protocol

no. time source destination protocol length info
2 0.001016 10.10.10.10 255.255.255.255 dhcp 365 dhcp offer - transaction id 0xf5bfe34d

frame 2: 365 bytes on wire (2920 bits), 365 bytes captured (2920 bits)
ethernet ii, src: tyancomp_b7:4f:70 (00:e0:81:b7:4f:70), dst: broadcast (ff:ff:ff:ff:ff:ff)
internet protocol version 4, src: 10.10.10.10 (10.10.10.10), dst: 255.255.255.255 (255.255.255.255)
user datagram protocol, src port: bootps (67), dst port: bootpc (68)
bootstrap protocol

no. time source destination protocol length info
3 0.103507 10.10.10.11 255.255.255.255 dhcp 365 dhcp offer - transaction id 0xf5bfe34d

frame 3: 365 bytes on wire (2920 bits), 365 bytes captured (2920 bits)
ethernet ii, src: vmware_b6:6a:63 (00:0c:29:b6:6a:63), dst: broadcast (ff:ff:ff:ff:ff:ff)
internet protocol version 4, src: 10.10.10.11 (10.10.10.11), dst: 255.255.255.255 (255.255.255.255)
user datagram protocol, src port: bootps (67), dst port: bootpc (68)
bootstrap protocol

no. time source destination protocol length info
4 1.002528 0.0.0.0 255.255.255.255 dhcp 342 dhcp request - transaction id 0xf5bfe34d

frame 4: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits)
ethernet ii, src: apple_46:43:43 (00:1f:f3:46:43:43), dst: broadcast (ff:ff:ff:ff:ff:ff)
internet protocol version 4, src: 0.0.0.0 (0.0.0.0), dst: 255.255.255.255 (255.255.255.255)
user datagram protocol, src port: bootpc (68), dst port: bootps (67)
bootstrap protocol

no. time source destination protocol length info
5 1.003946 10.10.10.10 255.255.255.255 dhcp 365 dhcp ack - transaction id 0xf5bfe34d

frame 5: 365 bytes on wire (2920 bits), 365 bytes captured (2920 bits)
ethernet ii, src: tyancomp_b7:4f:70 (00:e0:81:b7:4f:70), dst: broadcast (ff:ff:ff:ff:ff:ff)
internet protocol version 4, src: 10.10.10.10 (10.10.10.10), dst: 255.255.255.255 (255.255.255.255)
user datagram protocol, src port: bootps (67), dst port: bootpc (68)
bootstrap protocol

no. time source destination protocol length info
6 1.214093 0.0.0.0 255.255.255.255 dhcp 342 dhcp discover - transaction id 0xc0c98cdd

frame 6: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits)
ethernet ii, src: apple_86:15:2a (d8:30:62:86:15:2a), dst: broadcast (ff:ff:ff:ff:ff:ff)
internet protocol version 4, src: 0.0.0.0 (0.0.0.0), dst: 255.255.255.255 (255.255.255.255)
user datagram protocol, src port: bootpc (68), dst port: bootps (67)
bootstrap protocol

no. time source destination protocol length info
7 2.508236 0.0.0.0 255.255.255.255 dhcp 342 dhcp decline - transaction id 0x0

frame 7: 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits)
ethernet ii, src: apple_46:43:43 (00:1f:f3:46:43:43), dst: broadcast (ff:ff:ff:ff:ff:ff)
internet protocol version 4, src: 0.0.0.0 (0.0.0.0), dst: 255.255.255.255 (255.255.255.255)
user datagram protocol, src port: bootpc (68), dst port: bootps (67)
bootstrap protocol

granted example apple workstation happens on our windows 7 clients well.

when split-scopes used, correct method create full scope on both servers ("the right way") , create exclusions overlapping ips on each server. this important 2008 r2: http://www.itgeared.com/articles/1084-limitations-in-creating-reservations/

for example, if subnet 192.168.1.x/24 proper way create scope on each server have starting ip 192.168.1.1 , ending ip 192.168.1.254. then, if need 200 ips clients, exclude 100-254 on server 1, , exclude 1-99, 201-254 on server 2. then 201-254 can used static ip addresses (servers, network equipment, printers, etc...).

guides , tutorials, visit itgeared.com.