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BiPac 880AXL R2 persistent PTR rercord

Posted: Wed Apr 28, 2021 4:40 pm
by Ksaro1
I have inadvertently booted a Raspberry Pi 4 (RPI4) using the same hostname as another RPI4 on my home network. Once I've resolved this and rebooted both RPI4s the BiPac router still reports the PTR for the same (incorrect) hostname.

I see

pi@raspberrypi:~ $ dig -x 192.168.1.121
;; Warning: Message parser reports malformed message packet.

; <<>> DiG 9.11.5-P4-5.1+deb10u3-Raspbian <<>> -x 192.168.1.121
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 49176
;; flags: qr; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: f0da57d7fee81c5c (echoed)
;; QUESTION SECTION:
;121.1.168.192.in-addr.arpa. IN PTR

;; ADDITIONAL SECTION:
121.1.168.192.in-addr.arpa. 308231 IN PTR PiTv.home.gateway.

;; Query time: 1 msec
;; SERVER: 192.168.1.254#53(192.168.1.254)
;; WHEN: Wed Apr 28 15:37:02 BST 2021
;; MSG SIZE rcvd: 98

pi@raspberrypi:~ $ dig -x 192.168.1.100
;; Warning: Message parser reports malformed message packet.

; <<>> DiG 9.11.5-P4-5.1+deb10u3-Raspbian <<>> -x 192.168.1.100
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43025
;; flags: qr; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: 4bf134e17831d5c0 (echoed)
;; QUESTION SECTION:
;100.1.168.192.in-addr.arpa. IN PTR

;; ADDITIONAL SECTION:
100.1.168.192.in-addr.arpa. 308243 IN PTR PiTv.home.gateway.

;; Query time: 0 msec
;; SERVER: 192.168.1.254#53(192.168.1.254)
;; WHEN: Wed Apr 28 15:37:15 BST 2021
;; MSG SIZE rcvd: 98

pi@raspberrypi:~ $ dig PiTv.home.gateway
;; Warning: Message parser reports malformed message packet.

; <<>> DiG 9.11.5-P4-5.1+deb10u3-Raspbian <<>> PiTv.home.gateway
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 6786
;; flags: qr; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: 171aa59ffac2bb87 (echoed)
;; QUESTION SECTION:
;PiTv.home.gateway. IN A

;; ADDITIONAL SECTION:
PiTv.home.gateway. 311791 IN A 192.168.1.121

;; Query time: 1 msec
;; SERVER: 192.168.1.254#53(192.168.1.254)
;; WHEN: Wed Apr 28 16:36:21 BST 2021
;; MSG SIZE rcvd: 74

The IP address 192.168.1.121 is no longer leased to any device, yet the BiPac keeps resolving this to the PiTv host.

Is there any way to force the BiPac to drop this PTR record? Or is it the A record? Either way, the incorrect IP address is being resolved to the correct hostname.

Re: BiPac 880AXL R2 persistent PTR rercord

Posted: Wed Apr 28, 2021 4:50 pm
by billion_fan
Have you checked the DNS >> Static DNS entries??

Also have you tried to reboot the 8800?

Re: BiPac 880AXL R2 persistent PTR rercord

Posted: Thu Apr 29, 2021 1:25 pm
by Ksaro1
Thx for the reply. This IP address isn't a static IP address.

A reboot clears this. But why do I need to reboot? Isn't there some command or option that can clear old IP addresses? It seems a bit severe to have to reboot just to clear a mistaken hostname.

I'm also hesitant to reboot the BiPac due to the ongoing issue of my RPI4's DCHP lease being dropped and it then binds to a fallback IP address, which isn't part of the local address space. When I login to the RPI4 and check its Wifi state ,via the desktop Wi-Fi icon, it shows that it's successfully connected to the BiPac, but its IP address isn't part of the local LAN/WAN address space. I can do an interface down then up on the RPI4 and it reconnects to the BiPac and is issued a new IP address, which is part of the local LAN/WAN address space. This is an ongoing problem ticket, which I've heard no word on the progress of.

Re: BiPac 880AXL R2 persistent PTR rercord

Posted: Thu Apr 29, 2021 1:32 pm
by billion_fan
Ksaro1 wrote:
Thu Apr 29, 2021 1:25 pm
Thx for the reply. This IP address isn't a static IP address.

A reboot clears this. But why do I need to reboot? Isn't there some command or option that can clear old IP addresses? It seems a bit severe to reboot just to clear a mistaken hostname.
Unfortunately a reboot is the only way to clear the DNS records

Re: BiPac 880AXL R2 persistent PTR rercord

Posted: Thu Apr 29, 2021 2:20 pm
by Ksaro1
OK.

Re: BiPac 880AXL R2 persistent PTR rercord

Posted: Thu Apr 29, 2021 4:55 pm
by billion_fan
Ksaro1 wrote:
Thu Apr 29, 2021 1:25 pm
Thx for the reply. This IP address isn't a static IP address.

A reboot clears this. But why do I need to reboot? Isn't there some command or option that can clear old IP addresses? It seems a bit severe to have to reboot just to clear a mistaken hostname.

I'm also hesitant to reboot the BiPac due to the ongoing issue of my RPI4's DCHP lease being dropped and it then binds to a fallback IP address, which isn't part of the local address space. When I login to the RPI4 and check its Wifi state ,via the desktop Wi-Fi icon, it shows that it's successfully connected to the BiPac, but its IP address isn't part of the local LAN/WAN address space. I can do an interface down then up on the RPI4 and it reconnects to the BiPac and is issued a new IP address, which is part of the local LAN/WAN address space. This is an ongoing problem ticket, which I've heard no word on the progress of.
Ticket was replied on 30th March, some of the questions are irrelevant now as we have more information about the issue now :)