F5OS r2800 out-of-box DNS

[Andy-didnt-like-uucp]

Hi Guys
i'm a bit new to F5OS & need some help. i have fresh unpacked r2800 which i configured with 2 domestic DNSs only in RFC1918. But when i watch on tcpdump i can see chassis queries google DNSs along with domestic those:

12:20:21.423548 IP appliance-1.chassis.local.37917 > 8.8.8.8.domain: 48039+ AAAA? api.f5.com. (28)
12:20:21.423614 IP appliance-1.chassis.local.56070 > 8.8.8.8.domain: 17071+ A? api.f5.com. (28)
12:20:21.491076 IP appliance-1.chassis.local.56970 > <DOMESTIC-DNS>.domain: 48845+ PTR? 4.4.8.8.in-addr.arpa. (38)
12:20:25.423992 IP appliance-1.chassis.local.51778 > 8.8.4.4.domain: 17071+ A? api.f5.com. (28)
12:20:25.423992 IP appliance-1.chassis.local.57664 > 8.8.4.4.domain: 48039+ AAAA? api.f5.com. (28)

/etc/resolv.conf doesnt contain anything else except domestic DNSs. i'm a bit surprised... how can i disable querying google DNSs?

[Leslie_Hubertus]

Hey @Andy-didnt-like-uucp - that sounds like something an iRule could solve. My teammate Jason is on PTO this week, so maybe MVPs @Dario_Garrido or @StephanManthey could help?

[Dario_Garrido]

Hello @Andy-didnt-like-uucp ,

rSeries has its own interface to configure those DNS settings.

I recommend you to check this info

https://clouddocs.f5.com/training/community/rseries-training/html/initial_setup_of_rseries_platform_...

Please, let me know if this helps.

[Andy-didnt-like-uucp]

Hi Dario

this is basically how i gonfigured fresh box with domestic DNS & NTP. & then i've noticed chassis gueries GDNS. where this GDNS is configured in r2800's F5OS?

[Dario_Garrido]

Hello,

Do you have a static IP configuration in your management interface or DHCP?
Sometimes DHCP configuration can push a DNS configuration, so importing your home router DNS settings.

[Andy-didnt-like-uucp]

i have static IP

[Dario_Garrido · Accepted solution]

Hello @Andy-didnt-like-uucp,

Please, check this

https://my.f5.com/manage/s/article/K000134790

Let me know if it helps.

[Andy-didnt-like-uucp]

Hi Dario
in the 1st approach i shouldnt face it as per 

"Cause

When there is no dns server configured on host, the docker will use 8.8.8.8 and 8.8.4.4 to forward the dns request from docker containers. This is how docker behaves by design"

bc i have DNS servers configured :0)
F5LB01# show system dns
system dns state search [ <internal-domain-sanitized> ]
ADDRESS ADDRESS PORT
----------------------------
10.XX.YY.49 - 53
10.XX.YY.50 - 53

in the 2nd iteration how i can be sure i've restarted docker?
Recommended Actions

As a workaround you can set a fake internal ip which does not exist as dns server as block hole
Once you have custom DNS configured you need to restart docker

[Andy-didnt-like-uucp]

reboot chassis was of help. tnx