Hi, I just created an Ubuntu 20.04 VM (using Quick Create) in hyper-v on a Windows 10 Pro machine (version 1903, build 18362.836)
and while I can ping/telnet to other hosts (both on my local lan and also on the internet) DNS resolution does not work.
I am using the "default switch" for the VM with the default settings. The host machine has no issues with DNS resolution.
I also have an ubuntu console via WSL, and it has no issues with DNS resolution.
For example in the Ubuntu VM:
>nslookup microsoft.com
I get:
;; connection timed out; no servers could be reached
When I try name resolution with an external DNS server (e.g. cloudflare)
>nslookup microsoft.com 1.1.1.1
I get:
;; connection timed out; no servers could be reached
Or when I try this:
>dig @1.1.1.1 microsoft.com
I get:
; <<>> DiG 9.16.1-Ubuntu <<>> @1.1.1.1 microsoft.com
; (1 server found)
;; global options: +cmd
;; connection timed out; no servers could be reached
(both of these commands work find in my Ubuntu WSL console, and nslookup works find in the windows CMD terminal)
From within the Ubuntu VM:
I can ping the cloudflare DNS server using the ip address (e.g. ping 1.1.1.1) so networking and ICMP is working.
I can telnet to 1.1.1.1 on port 53, so TCP is working (other IPs work as well)
...and this works:
>nc -z -v -u 1.1.1.1 53
Connection to 1.1.1.1 53 port [udp/domain] succeeded!
So I can reach an external DNS server via UDP on port 53, and that works too, so doesn't seem like it can be a problem with networking, firewalls, VPNs, whatever... (I've tried several other public DNS servers, including google (8.8.8.8) with the same results.
...and yet no attempt to resolve a hostname (or even a reverse lookup) works.
Interestingly, if I force a TCP connection for dig with the +tcp flag, I can get hostnames to resolve, but only with external servers. In other words:
This works: >dig @1.1.1.1 microsoft.com +tcp
This does not: >dig microsoft.com +tcp
/etc/resolv.conf is:
nameserver 127.0.0.53
options edns0
search mshome.net
and the output of systemd-resolve --status is:
Global
LLMNR setting: no
MulticastDNS setting: no
DNSOverTLS setting: no
DNSSEC setting: no
DNSSEC supported: no
DNSSEC NTA: 10.in-addr.arpa
16.172.in-addr.arpa
168.192.in-addr.arpa
17.192.in-addr.arpa
18.192.in-addr.arpa
19.192.in-addr.arpa
20.192.in-addr.arpa
21.192.in-addr.arpa
22.192.in-addr.arpa
23.192.in-addr.arpa
24.192.in-addr.arpa
25.192.in-addr.arpa
25.192.in-addr.arpa
27.192.in-addr.arpa
28.192.in-addr.arpa
29.192.in-addr.arpa
30.192.in-addr.arpa
31.192.in-addr.arpa
corp
d.f.ip6.arpa
home
internal
intranet
lan
local
private
test
Link 2 (eth0)
Current Scopes: DNS
DefaultRoute setting: yes
LLMNR setting: yes
MulticastDNS setting: no
DNSOverTLS setting: no
DNSSEC setting: no
DNSSEC supported: no
Current DNS Server: 192.168.150.81
DNS Servers: 192.168.150.81
DNS Domain: ~.
mshome.net(note: 192.168.150.81 is the IP address of the "vEthernet (Default Switch)" Ethernet adapter)
Everything (hyper-V, the default switch, Ubuntu, etc.) is using default settings. I'm at a loss. I could understand if simply doing a name lookup via nslookup using the default name servers didn't work, as that is probably a resolver configuration problem.
However, specifying an external, reachable DNS sever, and it STILL fails to resolve (at least with the default UDP), and ONLY with the VM -- everything else, including WSL, works fine... I don't get it.
Anyone have any ideas?
