WAN DNS is not saved

[Unexus]

Running MX67 with latest stable firmware

DNS changes in WAN1 are not saved.

I have a new ISP and want to change the IP4 DNS values on the WAN1 side.

Currently they are 8.8.8.8 and 1.1.1.1. I follow the next steps:

• Sec & SD WAN > Appliance Status Uplink in the top menu
• Edit WAN Change DNS1/2 to 89.20.160.228/89.20.160.229 Pressing Update > Loading appears
• Back to the Applicance Status. Still the old values are shown
• Uplink in the top menu again This shows the new values
• Back to Appliance status shows the old values
• Click on Network Wide > Clients and back to Sec & SD WAN > Appliance status
• Click again on Uplink in the top menu Edit WAN1 > Shows the old values so new values are not saved.

[RWelch]

How long are you waiting for the change you made to take effect?  Typically it can take 60-90 seconds on a good day.  And you might have to refresh that page to see the change take effect after waiting 60-90 seconds.

Also, I just logged into the dashboard and it took me 4 tries before it actually allowed me access to the dashboard which isn't something I normally encounter.  It might be that you have to make the change when the dashboard is responding better without the hiccups or sluggishness.

[Unexus]

Figured out it works when you change DNS entries on the WAN side via <localip>/#configure screen. Sounds like a bug to me that changes are not applied via the cloud portal.

[cmr]

I made a similar change on an MX75 running 19.7.1 that is managed by shard 199.  I changed the DNS from the ISP to Cisco Umbrella.  The change took 58 seconds to take effect and using the Umbrella test page before and afterwards confirmed that it changed as expected.  @Unexus what shard are you on?  Does your connection allow DNS access to those IP addresses?  You can test this on a Windows laptop by going to a command prompt and typing:

• Nslookup (you should see a new prompt)
• www.cisco.com (the IP addresses should be returned)
• Server 89.20.160.228
• www.cisco.com (the IP addresses should be returned)

If the last part fails then you cannot access that DNS server.

[Brash]

Are you sure the IP addresses are correct?

It sounds like your config is reverting due to invalid DNS servers.

Looking up the two IP's you mentioned, they don't have DNS ports open (at least to the internet). They also don't have DNS server looking domain names:

89.20.160.228 · cns1.ef-service.nl

89.20.160.229 · cns2.ef-service.nl

On the other hand, this one looks to be a DNS server. Does it work if you try this IP address instead?

89.20.160.230 · dns1.ef-service.nl

[Unexus]

The DNS IP's are for my connection, provided by the ISP. As you can see from the screenshot I am able to use them for DNS lookup 

[RWelch]

This article describes best practices for configuring DNS servers on the WAN interfaces of all Cisco Meraki products. One of the most common DNS configurations when assigning a static IP address to a Meraki device is to use one ISP-provided DNS server and one well-known public DNS service such as Google (8.8.8.8). Many ISPs use their own hosted DNS server and may not have all records or have lookups to many publicly accessible servers.

Best Practices for DNS Configuration with Static IP Assignment