Hi all. I have just setup a DHCP/DDNS server for my LAN that contains several classless private IP DHCP subnets (/22). DHCP is currently giving clients an IP in the correct subnet, but the corresponding forward subdomain (vlanXXX.mydomain.zone) and reverse zones (1.X.0.zone) are not being updated. Instead, the master domain zone (mydomain.zone) and reverse zone (1.zone) files are being updated with A, TXT, and PTR records.
When I watch the debug logs, here is what I see.


DHCPDISCOVER from 00:18:8b:0a:59:b7 via 1.1.0.1
May 23 10:15:06 server-dev-001 dhcpd: DHCPOFFER on 1.1.1.250 to 00:18:8b:0a:59:b7 (client123) via 1.1.0.1
May 23 10:15:07 server-dev-001 named[7100]: client 1.254.0.50#32802: updating zone 'mydomain.local/IN': adding an RR at 'client123.mydomain.local' A
May 23 10:15:07 server-dev-001 named[7100]: client 1.254.0.50#32802: updating zone 'mydomain.local/IN': adding an RR at 'client123.mydomain.local' TXT
May 23 10:15:07 server-dev-001 named[7100]: zone mydomain.local/IN: sending notifies (serial 2007051505)
May 23 10:15:07 server-dev-001 dhcpd: Added new forward map from client123.mydomain.local to 1.1.1.250
May 23 10:15:07 server-dev-rno-dev-001 named[7100]: client 1.254.0.50#32802: updating zone '1.in-addr.arpa/IN': deleting rrset at '250.1.1.1.in-addr.arpa' PTR
May 23 10:15:07 server-dev-rno-dev-001 named[7100]: client 1.254.0.50#32802: updating zone '1.in-addr.arpa/IN': adding an RR at '250.1.1.1.in-addr.arpa' PTR
May 23 10:15:07 server-dev-rno-dev-001 dhcpd: added reverse map from 250.1.1.1.in-addr.arpa. to client123.mydomain.local

Since client123 rec'd it's IP from VLAN 101, I would expect to see client123 updating forward zone 'vlan101.mydomain.zone', and reverse zone file '1.1.0.zone', but it's instead updating mydomain.local and 1.zone. That's the problem.


Here's my setup: (I know I'm using public IP's, but this particular LAN will never be connected to the Internet in any way, shape,or form)


-------named.conf-------
...

# VLAN 101
zone "vlan101.mydomain.local" IN {
type master;
file "forward/vlan101.mydomain.zone";
allow-update {localhost;};
notify yes;
};

zone "0.1.1.in-addr.arpa" {
type master;
file "reverse/1.1.0.zone";
allow-update {localhost;};
notify yes;
};

# VLAN 149
zone "vlan149.mydomain.local" IN {
type master;
file "forward/vlan149.mydomain.zone";
allow-update {localhost;};
notify yes;
};

zone "0.4.1.in-addr.arpa" {
type master;
file "reverse/1.4.4.zone";
allow-update {localhost;};
notify yes;
};

# Top-Level
zone "mydomain.local" IN {
type master;
file "forward/mydomain.zone";
allow-update {localhost;};
notify yes;
};

zone "1.in-addr.arpa" {
type master;
file "reverse/1.zone";
allow-update {localhost;};
notify yes;
};
-----------------------------------------------------------------


------dhcpd.conf---------

authoritative; # No other DHCP servers on this subnet
ddns-update-style interim; # Supported update method - see man dhcpd.conf
ddns-domainname "mydomain.local";
ddns-updates on;
# ddns-update-style ad-hoc; # Add this instead of "interim" if not using ddns
ignore client-updates; # Overwrite client configured FQHNs

key "rndc.key" {
algorithm hmac-md5;
secret "*****************************";
};


# VLAN 101
zone vlan101.mydomain.local.in-addr.arpa { # Forward zone to be updated
primary 127.0.0.1;
key rndc.key;
}

zone 0.1.1.in-addr.arpa. { # Backward zone to be updated
primary 127.0.0.1;
key rndc.key;
}


subnet 1.1.0.0 netmask 255.255.252.0 {

range 1.1.0.10 1.1.3.250;
default-lease-time 21600;
max-lease-time 43200;

option routers 1.1.0.1; # Default gateway
option subnet-mask 255.255.252.0;
option domain-name "vlan101.mydomain.local";
option ip-forwarding off;
}

#vlan149
zone vlan149.mydomain.local. { # Forward zone to be updated
primary 127.0.0.1;
key rndc.key;
}

zone 0.4.1.in-addr.arpa. { # Backward zone to be updated
primary 127.0.0.1;
key rndc.key;
}

subnet 1.4.0.0 netmask 255.255.252.0 {

range 1.4.0.10 1.4.3.250;
default-lease-time 21600;
max-lease-time 43200;

option routers 1.4.0.1; # Default gateway
option subnet-mask 255.255.252.0;
option domain-name "vlan149.mydomain.local";
}


----------------------------------------------------------

Any ideas? Thanks all.

Brian

I fixed it by removing ddns-hostname in the dhcpd.conf file. This forces the value set in option domain-name to be used when registering in DNS.