topic Re: CISCO ISE DNS CONFIGURATION in Network Access Control

CISCO ISE DNS CONFIGURATION

lilianamartinez — Fri, 19 Nov 2021 21:57:18 GMT

Hi , I was searching cisco documentation about dns configuration on ISE , I was wondering if we can configure up to 3 DNS on ISE and primary DNS goes down , should ISE try to resolve by the secondary one? Today DNS primary goes down and it lose AD conectivity because of that a lot of user could,t authenticate, so costumer was asking to add a 3rd DNS to avoid this issue again.

Re: CISCO ISE DNS CONFIGURATION

balaji.bandi — Sat, 20 Nov 2021 00:21:07 GMT

, I was wondering if we can configure up to 3 DNS on ISE and primary DNS goes down , should ISE try to resolve by the secondary one?

yes, i do, but when you configure you need to restart the ISE service to take effect of new DNS Settings ? has this been done?

https://www.cisco.com/c/en/us/td/docs/security/ise/2-1/cli_ref_guide/b_ise_CLIReferenceGuide_21/b_ise_CLIReferenceGuide_21_chapter_011.html

When DNS Fails you can see the Logs in ISE, why it not able to resolve other DNS ? check the Logs ?

Re: CISCO ISE DNS CONFIGURATION

thomas — Tue, 30 Nov 2021 22:16:25 GMT

3 DNS servers are supported:

ise/admin# conf t
Enter configuration commands, one per line. End with CNTL/Z.
ise/admin(config)# ip name-server ?
<A.B.C.D>|<valid IPv6 format> Primary DNS server address
<A.B.C.D>|<valid IPv6 format> DNS server 2 IP address
<A.B.C.D>|<valid IPv6 format> DNS server 3 IP address

Re: CISCO ISE DNS CONFIGURATION

bkatrep — Wed, 12 Apr 2023 17:01:24 GMT

thomas. i removed the existing primary dns server ip on ise node and added a new one. i configured the old dns ip as the secondary and restarted the services on the node. But still seeing the DNS requests originating from the old server ip. any clue ? how to check a specific daemon

Re: CISCO ISE DNS CONFIGURATION

Marcelo Morais — Thu, 13 Apr 2023 03:46:14 GMT

Hi @bkatrep ,

please try to reload the Node.

Hope this helps !!!

Re: CISCO ISE DNS CONFIGURATION

ajc — Fri, 14 Jul 2023 21:07:00 GMT

I added a 3rd entry to ISE CLI DNS configuration and now the Node is completely stuck. See attached picture. I did a reload of the node, it did not help. the difference is that this new DNS server is a new Windows 2019 compare to the original 2 entries that are 2012.

Re: CISCO ISE DNS CONFIGURATION

manvik — Tue, 12 Mar 2024 14:10:18 GMT

ise/admin# show running-config ip

this will give you domain-name, IP and DNS

Re: CISCO ISE DNS CONFIGURATION

fdasilvanascimento — Fri, 15 Mar 2024 16:50:16 GMT

How Cisco ISE check the "ip host" ?

I set up the configuration below and Cisco ISE did not resolve the lab.company2 name.

ip name-server 192.168.100.30
!

ip host 10.10.200.10 lab.company2

Remarks: The name server 192.168.100.30 does not resolve lab.company2 due company business polices.

Re: CISCO ISE DNS CONFIGURATION

dsobrinho — Mon, 05 Aug 2024 18:21:46 GMT

Hi team,

One question, Should I reload the node after included 3 DNS? It is not clear for me

Re: CISCO ISE DNS CONFIGURATION

MSJ1 — Fri, 04 Oct 2024 14:35:28 GMT

@thomas How to find the DNS settings from GUI Interafce of ISE ?

Re: CISCO ISE DNS CONFIGURATION

Marcelo Morais — Mon, 30 Dec 2024 17:29:37 GMT

Hi @MSJ1 ,

please take a look at ISE - What we need to know about DNS Server.

Hope this helps !!!

Re: CISCO ISE DNS CONFIGURATION

seyyedmhashemian — Sun, 06 Apr 2025 13:29:08 GMT

Hi, Thanks. for example :

ise/admin(config)# ip name-server 192.168.1.2 192.168.1.3 192.168.1.200

Re: CISCO ISE DNS CONFIGURATION

CoMFPedreira — Fri, 07 Nov 2025 17:23:49 GMT

I just performed this operation now as suggested and noticed that it will only work if you reboot the server after each change. In my case I had to remove an old DNS server using no ip name-server x.x.x.x. Perform a reboot when prompted. Then add a new address ip name-server x.x.x.x. Perform another reboot. Then the settings get applied.

Previously I had tried to change both entries with a single reboot and only the second entry would get changed.

Hope this helps someone 🙂

Re: CISCO ISE DNS CONFIGURATION

Marcelo Morais — Fri, 07 Nov 2025 21:09:57 GMT

Hi @CoMFPedreira ,

please take a look at: ISE - What we need to know about DNS Server, special attention to:

" ... Each change (addition or deletion) using the ip name-server command causes the ISE Service to restart ... "

" ... the reset-config command (a command that can ONLY be run on the Console Port) reset the ADE-OS settings, such as Hostname, IP Addr, Mask, Def. Gateway, Domain Name, DNS Server, NTP Server and Timezone (parameters requested during Cisco ISE Setup), and can be used to reconfigure several parameters with just a single restart of the ISE Service. This command does not request the CLI Admin password, nor does it "reset" Cisco ISE Configuration or Operation Data (performed by the application reset-config command) ... "

Hope this helps !