Can not add remote host

I have a old server in ubuntu 18.04 lxd 3.0.3 and have a new server Ubuntu 20.04 lxd 4.12. But unfortunately I can’t add latest server as remote host. It shows below error

Error: Get https://x.x.x.x:8443: Service Unavailable lxd

Thats why I cannot migrate any container into latest server.What is the issue?

Hmm, that’s pretty weird as we don’t have code that can return that kind of error.
Are you sure you’re directly hitting a LXD server there?

Can you show lxc remote add some-name https://x.x.x.x:8443 --debug?

root@lxd1:~# lxc remote add lxd x.x.x.x --debug
DBUG[04-07|12:35:06] Connecting to a remote LXD over HTTPs
DBUG[04-07|12:35:06] Sending request to LXD method=GET url=https://x.x.x.x:8443/1.0 etag=
Error: Get https://x.x.x.x :8443: Service Unavailable

@stgraber they can ping each other,ssh each other but doesn’t’ add as remote. Plz help

@tomp do you have any idea?

Hi hafijaa,
Are you sure remote server is running lxd service, i mean. Is port open at remote side which you can check it out with the command: sudo nmap -sS <remote_server_ip>. If you have seen port 8443, then lxd is running and accept call.
P.S. You have to open port first.

lxc config set core.https_address :8443