Problem with dhcpd and ddns, deleting A record, leaving stale TXT/DHCID and PTR behind

Patrick Trapp ptrapp at nex-tech.com
Wed Mar 1 23:22:22 UTC 2017


The message came through successfully yesterday. I wish I had something to offer.

From: dhcp-users [mailto:dhcp-users-bounces at lists.isc.org] On Behalf Of Jess Johnson
Sent: Wednesday, March 1, 2017 5:17 PM
To: dhcp-users at lists.isc.org
Subject: Problem with dhcpd and ddns, deleting A record, leaving stale TXT/DHCID and PTR behind

Apologies if multiples of these get through. I've been trying to send to the list for a couple of days and not having any luck.

Summary - dhcpd removes A record, but leaves DHCID and PTR behind, causing problems in future.

dhcpd 4.3.5 (custom install with no options to configure)
bind-9.8.2-0.47.rc1.el6_8.3.x86_64

ddns-updates on;
ddns-update-style standard;
ddns-rev-domainname "in-addr.arpa.";
update-optimization off;
#update-conflict-detection false;

update-static-leases on;
ignore client-updates;
one-lease-per-client on;

We are using host definitions as such

host esxi-xxxx-a5-30-10 {
  hardware ethernet 2C:59:E5:49:56:38;
  ddns-hostname "esxi-xxxx-a5-30-10";
  ddns-domainname "domain.com<http://domain.com/>.";
  option host-name "esxi-xxxx-a5-30-10";
  option domain-name "domain.com<http://domain.com/>";
}

The host boots on untagged network (no DDNS), PXE boots ESXi with tagged interface on different VLAN with DDNS enabled. At this point it registers A, PTR and DHCID just fine.
Autodeploy then applies a host profile which cause the interface to down/up on the same network segment. When it goes down, dhcp removes the A record, but not the DHCID or PTR. When it comes back up on the same IP address (MAC address stayed the same), I get

Feb 28 19:16:22 dhcp001 dhcpd: DHCPOFFER on 10.1.66.37 to 2c:59:e5:49:15:98 via 10.1.66.2
Feb 28 19:16:22 dhcp001 dhcpd: DHCPREQUEST for 10.1.66.37 (10.1.71.135) from 2c:59:e5:49:15:98 via 10.1.66.2
Feb 28 19:16:22 dhcp001 dhcpd: DHCPACK on 10.1.66.37 to 2c:59:e5:49:15:98 via 10.1.66.2
Feb 28 19:16:22 dhcp001 dhcpd: Added new forward map from esxi-xxxx-a5-30-14.domain.com<http://esxi-xxxx-a5-30-14.domain.com/>. to 10.1.66.37
Feb 28 19:18:58 dhcp001 dhcpd: DHCPRELEASE of 10.1.66.37 from 2c:59:e5:49:15:98 via eth0 (found)
Feb 28 19:18:58 dhcp001 dhcpd: Removed forward map from esxi-xxxx-a5-30-14.domain.com<http://esxi-xxxx-a5-30-14.domain.com/>. to 10.1.66.37
Feb 28 19:19:01 dhcp001 dhcpd: DHCPOFFER on 10.1.66.37 to 2c:59:e5:49:15:98 via 10.1.66.3
Feb 28 19:19:01 dhcp001 dhcpd: DHCPREQUEST for 10.1.66.37 (10.1.71.135) from 2c:59:e5:49:15:98 via 10.1.66.3
Feb 28 19:19:01 dhcp001 dhcpd: DHCPACK on 10.1.66.37 to 2c:59:e5:49:15:98 via 10.1.66.3
Feb 28 19:19:04 dhcp001 dhcpd: DHCPREQUEST for 10.1.66.37 from 2c:59:e5:49:15:98 via eth0
Feb 28 19:31:52 dhcp001 dhcpd: Forward map from esxi-xxxx-a5-30-14.domain.com<http://esxi-xxxx-a5-30-14.domain.com/>. to 10.1.66.37 FAILED: timed out
and
updating zone 'domain.com/IN<http://domain.com/IN>': update unsuccessful: esxi-xxxx-a5-30-10.domaincom: 'name not in use' prerequisite not satisfied (YXDOMAIN)

# host -a esxi-xxxx-a5-30-10.domain.com<http://esxi-xxxx-a5-30-10.domain.com/>
Trying "esxi-xxxx-a5-30-10.domain.com<http://esxi-xxxx-a5-30-10.domain.com/>"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 42622
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 3

;; QUESTION SECTION:
;esxi-xxxx-a5-30-10.domain.com<http://esxi-xxxx-a5-30-10.domain.com/>. IN ANY

;; ANSWER SECTION:
esxi-xxxx-a5-30-10.domain.com<http://esxi-xxxx-a5-30-10.domain.com/>. 3600 IN DHCID AAEBABsJWn8ZMp8B0wG1h6pv4FVrVZobDzBUVM8QVYrQPak=

;; AUTHORITY SECTION:
domain.com<http://domain.com/>.  86400   IN      NS      dns002.domain.com<http://dns002.domain.com/>.
domain.com<http://domain.com/>.  86400   IN      NS      dns003.domain.com<http://dns003.domain.com/>.
domain.com<http://domain.com/>.  86400   IN      NS      dns001.domain.com<http://dns001.domain.com/>.


It's my understanding it should be deleting the DHCID record because there is no A record? The esxi server still has a valid lease on 10.1.66.34

What am I missing?
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