Issue with DDNS with named/dhcpd

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johndabomb44
Posts: 10
Joined: 2020/03/17 14:20:44

Issue with DDNS with named/dhcpd

Post by johndabomb44 » 2020/08/27 21:42:43

Hey all!


Trying to figure out DDNS with bind and dhcpd on CentOS 7. If I enable the "ddns-update-style interim" line in /etc/dhcp/dhcpd.conf, it causes dhcpd to abort when the first client reaches out for an IP. This is the error I get:

dhcpd.service - DHCPv4 Server Daemon
Loaded: loaded (/usr/lib/systemd/system/dhcpd.service; enabled; vendor preset: disabled)
Active: failed (Result: signal) since Thu 2020-08-27 16:38:09 CDT; 8s ago
Docs: man:dhcpd(8)
man:dhcpd.conf(5)
Process: 13823 ExecStart=/usr/sbin/dhcpd -f -cf /etc/dhcp/dhcpd.conf -user dhcpd -group dhcpd --no-pid (code=killed, signal=ABRT)
Main PID: 13823 (code=killed, signal=ABRT)
Status: "Dispatching packets..."

Aug 27 16:35:20 is01 dhcpd[13823]: Listening on LPF/enp0s3/08:00:27:4d:40:76/172.16.1.0/24
Aug 27 16:35:20 is01 dhcpd[13823]: Sending on LPF/enp0s3/08:00:27:4d:40:76/172.16.1.0/24
Aug 27 16:35:20 is01 dhcpd[13823]: Sending on Socket/fallback/fallback-net
Aug 27 16:35:20 is01 systemd[1]: Started DHCPv4 Server Daemon.
Aug 27 16:38:08 is01 dhcpd[13823]: DHCPDISCOVER from 08:00:27:7f:b5:b5 via enp0s3
Aug 27 16:38:09 is01 dhcpd[13823]: DHCPOFFER on 172.16.1.11 to 08:00:27:7f:b5:b5 (ws02) via enp0s3
Aug 27 16:38:09 is01 dhcpd[13823]: ../../../lib/isc/md5.c:65: fatal error: Cannot initialize MD5.
Aug 27 16:38:09 is01 systemd[1]: dhcpd.service: main process exited, code=killed, status=6/ABRT
Aug 27 16:38:09 is01 systemd[1]: Unit dhcpd.service entered failed state.
Aug 27 16:38:09 is01 systemd[1]: dhcpd.service failed.


This is my /etc/dhcp/dhcpd.conf file:


allow unknown-clients;
allow client-updates;
ddns-updates on;
ddns-update-style interim;
ddns-domainname "linint.virtnet";
ddns-rev-domainname "in-addr.arpa";


key rndc-key {
algorithm hmac-sha512;
secret REDACTED;
}


subnet 172.16.1.0 netmask 255.255.255.0 {
allow client-updates;
ddns-updates on;
option routers 172.16.1.1;
option subnet-mask 255.255.255.0;
option domain-name-servers 172.16.1.3, 172.16.1.4, 192.168.1.2;
option domain-name "linint.virtnet";
option domain-search "linint.virtnet";
range 172.16.1.11 172.16.1.250;
default-lease-time 3600;
max-lease-time 7200;
}

zone linint.virtnet. {
primary 172.16.1.3;
key rndc-key;
}

zone 1.16.172.in-addr.arpa. {
primary 172.16.1.3;
key rndc-key;
}



Everything works perfectly if I has out the referenced DDNS line (as in a client get all the info in the subnet specified and is able to interact with any records already in the DNS servers.)

johndabomb44
Posts: 10
Joined: 2020/03/17 14:20:44

Re: Issue with DDNS with named/dhcpd

Post by johndabomb44 » 2020/08/28 14:59:38

Disregard this thread:


I guess recently ISC finally updated ddns and all the tutorials I found were from a year ago.


If you're setting up a new DNS server, you can now use "ddns-update-style standard;"

The MD5 error went away on service restart and new computers were able to pull a lease and have dhcpd send its info to named for updating DNS records successfully.

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