Avi DNS validation fails if using a different DNS server than system

[carlosonunez-vmw]

What happened?

The Arcas UI fails to validate Avi FQDNs if the records are not present on the system's DNS server regardless of whether a custom DNS server is provided or not.

How to reproduce

1. install dnsmasq on the SIVT appliance (yum -y install dnsmasq)
2. Add the following to /etc/dnsmasq.conf:

listen-address=127.0.0.1,::1,10.220.3.251
server=8.8.8.8
server=8.8.4.4
address=/avi-01.tkg.local/172.16.10.10
address=/avi-02.tkg.local/172.16.10.28
address=/avi-03.tkg.local/172.16.10.29
address=/avi-cluster.tkg.local/172.16.10.30
interface=eth0
expand-hosts
domain=tkg.local

3. Add this line to /etc/systemd/resolved.conf:

DNSStubListener=no

4. Restart dnsmasq and systemd-resolved: systemctl restart systemd-resolved dnsmasq
5. Confirm that avi-01.tkg.local is resolvable locally:

dig @127.0.0.1 avi-01.tkg.local +short
172.16.10.10

6. Confirm that avi-01.tkg.local is NOT resolvable by your system's resolver:

dig avi-01.tkg.local +short

7. Start the Service Installer UI.
8. Set the DNS server to 127.0.0.1
9. Add Avi records as shown in the dnsmasq.conf file above

What should happen?

Validation should pass

What actually happens?

Validation hangs for a few seconds then fails.

Additional notes

• This is happening because you need to append an @ before your DNS server in the line here.