Alan_F
August 30, 2024, 12:39pm
1
@gopher.ny - TLDR: The new endpoint to remove the backup DNS configuration doesn't work. DNS is a hot mess.
I updated to 2.3.9.176 and used the new endpoint to "out from backup DNS configuration"
On my C9-Pro here were the results:
Starting from running static IP with defined local DNS servers:
After setting to "false" and prior to rebooting, only my two local DNS servers were listed under DNS servers in in http://hubitat.home.lan/hub2/networkConfiguration
After rebooting, no DNS servers were listed. I could not ping any resource by name, local or internet
After clicking "switch to static IP" and "Save and switch to static IP" my DNS servers were showing in http://hubitat.home.lan/hub2/networkConfiguration and I could ping local and internet URLs
After rebooting, I lost all DNS again. No servers were listed
After switching to DHCP but prior to rebooting, my DNS servers were showing and DNS worked.
After rebooting with DHCP active, my DNS servers were present, but 8.8.8.8 was added to the end of the list.
After my DHCP lease renewed, 8.8.8.8 was moved to the top of the list, breaking local name resolution (see C-8 Pro - local DNS fails after DHCP lease renews - #10 by bravenel )
I switched back to static IP. Prior to rebooting, the hub2/network configuration showed my two servers, then 8.8.8.8, then my two servers again.
After rebooting, I had no DNS servers listed again
I switched the endpoint back to TRUE and rebooted (still using static IP). My DNS servers weren't listed at all in "dnsServers" :
{"usingStaticIP":true,"staticIP":"192.168.0.9","staticGateway":"192.168.0.1","staticSubnetMask":"255.255.255.0","staticNameServers":["192.168.0.12","192.168.0.13"],"dhcpNameServers":["192.168.0.12","192.168.0.13"],"dnsServers":["8.8.8.8","8.8.4.4","1.1.1.1","1.0.0.1","9.9.9.9"]
I clicked "Save and switch to static IP" (remember... I was already running static IP) and my DNS servers were re-added to the list
{"usingStaticIP":true,"staticIP":"192.168.0.9","staticGateway":"192.168.0.1","staticSubnetMask":"255.255.255.0","staticNameServers":["192.168.0.12","192.168.0.13"],"dhcpNameServers":["192.168.0.12","192.168.0.13"],"dnsServers":["192.168.0.12","192.168.0.13","8.8.8.8","8.8.4.4","1.1.1.1","1.0.0.1","9.9.9.9"],
After a reboot, my DNS servers are gone again
{"usingStaticIP":true,"staticIP":"192.168.0.9","staticGateway":"192.168.0.1","staticSubnetMask":"255.255.255.0","staticNameServers":["192.168.0.12","192.168.0.13"],"dhcpNameServers":["192.168.0.12","192.168.0.13"],"dnsServers":["8.8.8.8","8.8.4.4","1.1.1.1","1.0.0.1","9.9.9.9"],
So in summary, I haven't found any method to get my DNS servers to be used that can survive both a hub reboot and a DHCP renewal. If I use static, I lose my servers after a reboot. If I use DHCP, my servers get pushed from the top of the list after a DHCP renewal.
The only way I can figure out to use my local DNS servers for now is to use static IP and not reboot after clicking 'save and switch to static IP".
No mention of values for Override DNS settings option in Settings -> Network Setup?
Alan_F
September 2, 2024, 12:09pm
3
I've tried both with and without Override DNS settings. Since I was setting them the same as the DNS servers supplied by my router, the result was the same either way. I tried a soft reset to see if that would help, but nothing changed.
For now I'm using static IP and I have to remember to go into the hub and click the "Save and Switch to Static IP " button after any reboot.
The issue with DHCP has been present ever since I got my C8-Pro. The issue after a reboot using static IP is new.
My hubs are on DHCP, with a value set in Override DNS, and I have exercised the new endpoint to opt out of backup DNS:
{
"usingStaticIP":false,
"staticIP":null,
"staticGateway":null,
"staticSubnetMask":null,
"staticNameServers":[],
"dhcpNameServers":["192.168.1.1"],
"dnsServers":["192.168.1.1"],
"lanAddr":"192.168.1.219",
"wlanAddr":null,
"wifiNetwork":null,
"wifiMessage":"WiFi is detected.",
"ipMessage":"Hub's IP address is <a href=\"http://192.168.1.219\">192.168.1.219</a> (Ethernet) via <b>DHCP</b>.",
"lanAutoneg":"AUTONEG",
"hubVersion":8,
"wifiDriversInstalled":true,
"hasEthernet":true,
"hasWiFi":false
}
and I have not seen an issue of loosing name resolution.
FWIW, my firewall blocks direct access to external DNS
1 Like
ramset
September 2, 2024, 5:24pm
5
+1 to this.
I do get the occasional hiccup, where it says no cloud connection available, however, running the network tests (including trace or ping on hostname where DNS request IS resolved using the defined DNS server) works.
I’ve been “barking” about the hard coded DNS for quite some time:
Updated to the latest version 2.2.5.119
The update was successful however a DNS relate problem surfaced after the reboot.
While my C5 took the update and worked flawlessly after the reboot, the C7 apparently was stuck on a ?hard coded? DNS (blocked at router level - i only allow a specific DNS).
I tried setting the DNS manually in the new feature available for that, it saved my DNS but no queries went through that. The hub still used the other one.
I restored to 2.2.4.158 and the issue persi…
Due to a corrupt database today, I had to restore the hub and sadly I got confirmation that it used internally stored DNS servers.
I had a complex network outage and the hub joined the network on a diferent IP than what I usually had it on.
The originally “assigned” IP had a hole in the firewall for the DNS requests as I suspected that in some cases, it ignores the DHCP assigned DNS.
Is that a desired behavior for the hub since it comes packaged with a master DNS server in the platform?
1 Like
Trying to use hubitat.local in the address bar is failing for me on .176 as well.
That's not a DNS server issue as discussed in this thread. The domain .local belongs to mDNS which is a completely different protocol set.
1 Like
Fair enough. I'm just pointing out that it's not working either. I mentioned it in another thread too but it was ignored entirely so at least this time it got a reply.
A 2.3.9 hotfix is coming to sort it out.
2 Likes
Alan_F
September 3, 2024, 8:17pm
11
Just to clarify, are you responding to my OP, to the post about hubitat.local, or both?
1 Like
The fix is for DNS screw-ups as described in the topmost post.
"hubitat.local" name can be overridden in hub details. If that's done, hubitat.local is no longer available and is replaced with the name specified there. Does your hub still say "hubitat" there and is not resolving locally?
1 Like
As noted above, the issue raised in the OP is about DNS, not mDNS.
It’s kind of confusing to keep bringing up mDNS issues in the same thread.
4 Likes
For DNS fix, please grab 2.3.9.177, just released.
2 Likes
system
October 5, 2024, 5:52pm
16
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