PfSense serving old DNS records - DNS Resolver / unbound

roderick1st

Hi,

I am having an issue where pfSense is serving up old statically set DNS records. Im using DNS resolver (unbound)

I had a Host Overide set as hass.test.local -> 192.168.5.50

I then changed the Host Overide to hass.test.local -> 192.168.5.52 (Server IP had changed as moving service to different server)

When I clear the DNS cache on my windows machine I now get served the old IP and the new IP with the old being at the top of the list.

nslookup hass.test.local
Server : gateway.test.local
Address: 192.168.1.1

Name: hass.test.local
Address: 192.168.5.50
      192.168.5.52

If I run Dig on the pfSense box I get both IP address returned.


dig hass.test.local

; <<>> DiG 9.11.2 <<>> hass.test.local
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 65408
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;hass.test.local.      IN      A

;; ANSWER SECTION:
hass.test.local. 3600  IN      A       192.168.5.50
hass.test.local. 3600  IN      A       192.168.5.52

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Sat Mar 03 23:41:17 UTC 2018
;; MSG SIZE  rcvd: 85

I have restarted unbound.

I have flushed the cache

unbound-control -c /var/unbound/unbound.conf flush_zone test.local

I cant find any reference to hass in the cache

unbound-control -c /var/unbound/unbound.conf dump_cache | grep test.local

Any suggestions on how to remove the old IP and stop it being served out to clients?

roderick1st

I have found a fix but I'm not sure if this is a bug or general unbound behaviour.

To fix:
I deleted all references to hass.test.local in the Host Overrides section (in the GUI)

Restarted unbound service (GUI)

re added hass.test.local -> 192.168.5.52 (GUI)

Reviewing the host_entries.conf file all old hosts were still in the file so I manually removed them with vi leaving only the correct host. (Console)

Restarted unbound service (GUI)

Fixed!

Is there a bug in the Host Overrides sections where old host references are not being deleted?

roderick1st

Sorry, answering my own post again but I think I have found the real reason.

I still had the new server getting and IP address through DHCP and had left it statically assigned an address with the old hostname Hass. I think this must have been registering in unbound.

johnpoz

Yes a dhcp reservation/static can be set to registered. Doing so and then creating a host overrride with a different IP would give you 2 IPs for the same host name.