DHCP not giving out DNS address

stewii

I am running 2.3.2-RELEASE-p1. My problem is the DHCP leases are not handing out the DNS ip address I want. When my clients talk to my pfsense box they get the ip of the pfsense box (192.168.1.1) not the IP I set in the DHCP >Services >DHCP Server>LAN 3rd set of option down "servers" I set the address I want DHCP to hand out (192.168.1.10). On a windows 7 and 10 box I have done a ipconfig /release and renew and when I run ipconfig /all it still shows 192.168.1.1 as my dns address.

Things that might cause the problem but I have no idea.
The DNS IP is not in the DHCP pool range.
The DNS IP is in a static mapping for DHCP
I only have the one IP in the DNS server nothing under wins
DNS resolver is not enabled

Services>DNS Forwarder page (i messed around with this page trying to get this to work so not sure if these are correct anymore)

Enable checked

DHCP Registration checked

Static DHCP checked

Prefer DHCP checked

DNS Query Not checked

Services>Dynamic DNS>Dynamic DNS Clients page I use opendns
I have tried to uncheck this page and still get the same dns IP of 192.168.1.1

running pfBlockerNG but doubt it has anything to do with this issue

I hope this is an easy fix. I'm guessing I forgot to do something or check a box. Thanks!

Derelict

It is probably hard-set in windows. You can get a dynamic address with hard-set DNS servers.

Packet capture the DHCP exchange and see what the DHCP server is actually sending. You will likely find it is exactly what is set in the DHCP server.

stewii

Did the dump with wireshark. Followed this guide https://en.wikiversity.org/wiki/Wireshark/DHCP and do not see anything in there with the DNS server IP address that I am specifying in the DHCP server.

edit: If this is hard set in windows would my linux/android clients get the dns entry? How would I go about fixing it in windows if it is hard set?

Derelict

If windows has it hard set remove it from the interface config in windows.

johnpoz

Didn't see anything? How about you post it…

So show us that you wanting to hand out 192.168.1.10, for example I hand out 192.168.3.10 -- here I did a release and then renew, you can see in the offer 192.168.3.10 was offered..

dnsviadhcp.png_thumb

stewii

Thanks for pointing out where to look. I changed it to 192.168.1.52 just to try and still receiving 192.168.1.1. See attachments. I think I just realized what you meant by windows hard set. No it is not hard set.

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Derelict

You have another DHCP server on your network. Look at the source MAC address of the DHCP server responses.

johnpoz

Or you have a reservation setup for that client.. Your client is 192.168.1.7 but your pool is 150-254 so clearly its not coming from that pool..

Notice my pool, my client .100 is outside that pool I have a reservation/static for it set..

staticreservation.png_thumb

stewii

Don't have a second DHCP server but I do have a static reservation for the client. Almost all of my clients have a static reservation. So this brings up two questions.

1. if I use a DHCP reservation on pfsense how do I send DNS to the client that gets the reservation without hard setting it on the client?

2 I have other non windows clients (Sonos and android) that are in the DHCP pool that do not report back to my dns server 192.168.1.52 (remember I changed it). If DHCP is sending out DNS why wouldn't these clients use the DNS that it is supposed to from DHCP?

johnpoz

" If DHCP is sending out DNS why wouldn't these clients use the DNS that it is supposed to from DHCP?"

because they haven't updated their lease yet??

So set the dns you want your client to use in the reservation.. If you don't then yeah its going to get the IP address your dhcp server is running on as default.

reservation.png_thumb

stewii

So after a reboot of pfsense, everything started working as it should. I guess the reboot released all the static leases?

johnpoz

huh? Or you client updated its lease.. And the reboot had zero to do with it..

stewii

I guess I should have been more clear. After a reboot of pfsense, all clients started talking to my DNS server as it is configured in pfsense. Meaning all clients windows linux android and whatever sonos runs on(probably linux) started reporting into the DNS server at 192.168.1.52. So take it how you want….