failover and duplicate leases

[Tina Siegenthaler]

Hi all

I have setup failover, and now I'm getting a lot of log entries in  
like this:


Mar 21 08:18:24 zool-admin04 dhcpd: uid lease 130.60.226.92 for  
client 00:c0:ca:12:ff:7e is duplicate on 130.60.226.0/25

A whole DISCOVER-OFFER-REQUEST cycle in such cases goes like that:

On the primary:
Mar 21 08:02:45 zool-admin04 dhcpd: DHCPDISCOVER from 00:03:93:a9:2c: 
02 via 130.60.225.129
Mar 21 08:02:46 zool-admin04 dhcpd: DHCPOFFER on 130.60.225.153 to  
00:03:93:a9:2c:02 via 130.60.225.129
Mar 21 08:02:46 zool-admin04 dhcpd: uid lease 130.60.225.153 for  
client 00:03:93:a9:2c:02 is duplicate on 130.60.225.128/25
Mar 21 08:02:46 zool-admin04 dhcpd: DHCPREQUEST for 130.60.225.174  
(130.60.23.114) from 00:03:93:a9:2c:02 via 130.60.225.129: lease  
owned by peer

On the secondary:
Mar 21 08:02:45 DHCP-0352 dhcpd: DHCPDISCOVER from 00:03:93:a9:2c:02  
via 130.60.225.129
Mar 21 08:02:46 DHCP-0352 dhcpd: DHCPOFFER on 130.60.225.174 to  
00:03:93:a9:2c:02 via 130.60.225.129
Mar 21 08:02:47 DHCP-0352 dhcpd: uid lease 130.60.225.208 for client  
00:03:93:a9:2c:02 is duplicate on 130.60.225.128/25
Mar 21 08:02:47 DHCP-0352 dhcpd: DHCPREQUEST for 130.60.225.174  
(130.60.23.114) from 00:03:93:a9:2c:02 via 130.60.225.129
Mar 21 08:02:47 DHCP-0352 dhcpd: DHCPACK on 130.60.225.174 to  
00:03:93:a9:2c:02 via 130.60.225.129

I just wonder who is offering it the 130.60.225.208 address? I  
certainly don't have another dhcp server running, and neither should  
anybody else... And why do the peers offer different addresses?  
They're supposed to synchronize their lease databases, aren't they?  
Like this, I have a lot of clients who get a different address every  
day. Well, everything works out fine in the end, the client gets a  
valid lease, but I'm still curious if this is normal behavior.


Setup:
dhcp 3.0.4 on Mac OS X 10.4.8
config files:

primary:

failover peer "DHCP-Zool" {
         primary;
         address 130.60.23.4;
         port 520;
         peer address 130.60.23.114;
         peer port 520;
         max-response-delay 60;
         max-unacked-updates 10;
         mclt 1800;
         split 128;
         load balance max seconds 5;
}

include "/etc/dhcpd.master";


secondary:

failover peer "DHCP-Zool" {
         secondary;
         address 130.60.23.114;
         port 520;
         peer address 130.60.23.4;
         peer port 520;
         max-response-delay 60;
         max-unacked-updates 10;
         load balance max seconds 5;
}

include "/etc/dhcpd.master";






**********************************************
Dr. Tina Siegenthaler

IT support

Institute of Zoology
University of Zurich
Winterthurerstr. 190
8057 Zürich

tel : ++41 44 6354891
email: tina at zool.uzh.ch
**********************************************