Change DNS on MR33 connected to MX64

[Aesa]

We recently upgraded our Dc to Server 2019 and changed the local IP.

I need to edit the DNS setting on both of our MR33 devices but can find no documentation on how to do this. Any help would be greatly appreciated.

[Nash]

Have you tried the methods in this document: https://documentation.meraki.com/MR/Monitoring_and_Reporting/Static_IP_Assignment_on_a_Cisco_Meraki_...

I'd post excerpts but they're fairly long. 🙂

[Aesa]

Yes, I have tried that. The current setting is DHCP. When I change to Static, edit the DNS settings and click save, the value does not change. It stay on DHCP and the old DNs remains.

[Nash]

When you say value, do you mean the assigned IP? Or the place where you config a static IP on the AP itself?

If on the AP itself, is the config updating?

If it's staying on a DHCP IP address, are you getting an IP address on the same subnet as the static would be? Can that AP ping the gw for the static IP?

[Aesa]

I removed the old DHCP entries for both APs. I then edited as described on the help page you posted, setting the IP to a different static IP, added the gateway and DNS server IPS, clicked save and restarted both APs.

This snip shows my changes

This snip shows the results after restarting one of the APs. The values are the same as they were before the changes made above.

[PhilipDAth]

Why can't you leave the AP on DHCP and just pick up the new settings from your DHCP server?

[Nash]

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@PhilipDAth wrote:

Why can't you leave the AP on DHCP and just pick up the new settings from your DHCP server?

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Honestly, this. I'm in an environment where people are forcing manually configured static IPs.

My preference would be DHCP reservation, specifically so you can easily change things like DNS.

[Aesa]

For whatever reason, the DHCP server, which is installed on the primary DC, is not pushing the new DNS address to the access points. This is why I wanted to try setting them as static, to force the DNS setting on the APs to point to the correct DNS servers.

[Nash]

Okay, if the DHCP server is being weird, I think that's where you need to be looking. Not so much on the APs, especially if you've already forced a reboot/forced them to grab a new lease.

[BrechtSchamp]

I'd do a packet capture and have a look at the DHCP process for one of the APs after reboot. Look at what's in there (what's the AP asking, what's the server giving). That should let you know where to look next.

[Aesa]

I am very new to the Meraki environment. Where would I perform the packet capture on the AP

[NolanHerring]

That snip is showing it still using DHCP and not STATIC like your configuration above.

If you rebooted, then they should grab new DNS by that action alone. Are you sure the 192.168.100.14 isn't still being provided somewhere?

[Aesa]

Absolutely positive the 192.168.100.14 address is no longer in use.

[ww]

the vlan field must be empty when setting a static ip on the AP.    assign it a IP in the native vlan thats configured on the connected switchport

[Aesa]

It is empty

[Aesa]

I found the issue with DHCP/DNS. I had a legacy entry in the scope settings. Once I removed it, the correct DNS server was pushed to the APs.

Thanks to all. Your suggestions pointed me in the right direction.

[PhilipDAth]

Have you updated the DHCP server to give out the new IP address for your new AD controller?

[NolanHerring]

Anytime I've waited for DNS to update when using DHCP, I end up rebooting the access point to force it to update.

[Brons2]

In my experience it takes a while for the web pages to update when you change the IP from DHCP to static on a new switch or AP.  I just wait.