login to ubuntu 18.04 server

Jasmin shahrzad
Jasmin shahrzad used Ask the Experts™
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i have an ubuntu 18.04 (upgrade from ubuntu 16.04) it was menber of domain as ubuntu 16.04 (in samba active directory).
After upgrade i can't see this server in my dns. but it's there because i can't add it as a new host. dns error: "the record alredy exists.)
it's take min. 5 minutes to login via ssh to server.
 what should i do? what is wrong?
in var/log/auth.log is error entry every 2 min. pam_unix(cron:session): session opened for user root by (uid=0) then after 2 min. pam_unix(cron:session): session closed for user root
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Fractional CTO
Distinguished Expert 2018
Commented:
1) Make sure port 22 is open every where (your source machine + inside VM instance).

2) Try logging in as ubuntu/ubuntu (default user).

Note: Trying to do an in place update from Xenial to Bionic, to me, is a very bad idea, because Bionic replumbs/replaces the entire networking subsystem with Netplan, so upgrades for Artful work + any previous version... has mixed results...

Better to do a fresh install + restore a backup, as the likely problem is your networking subsystem, which will take a very long time to untangle.

3) Once you have Bionic installed, consider running LXD containers for your Apps, so you can completely avoid this in the future by moving your LXD containers to another machine during upgrades.

I've started doing this, so if any upgrade or fresh install has problems, I can just do another reinstall with no effect on live sites... which are safely running on some other machine.
Distinguished Expert 2017

Commented:
Static IPs shoukd be added as a permanent record.
If you rely on the samba side to register the domain in DNS, your scavenging process likely cleared the DNS record
David FavorFractional CTO
Distinguished Expert 2018

Commented:
Was just re-reading this, "After upgrade i can't see this server in my dns."

Maybe explain exactly what this means, as DNS will never change because of some site upgrade.

Unless maybe your DNS is adaptive, meaning all IPs are pinged + bad IPs removed. If this is what you mean, then likely NetPlan update is the problem. Be sure you ping your IP to determine if the IP is even responding. If you get no ping back, then NetPlan update is almost certainly the problem.
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Author

Commented:
Thanks David,
you are right under upgrade i close for port 22. i open the port it's mach better.
but i still have problem i running wbinfo -u to see domain users : erroe looking up domain users.

i try kinit Administrator it's take a 2-3 min. to answer.
i have a many lxd images on this server and don't have a any problem.all v. server on it runnig fine.
fx. command like this sudo systemctl status smbd nmbd winbind  just waiting 4 min. to answer.

Author

Commented:
yes i never see it before. after upgrade i can't see my server in my dns but it's here because i can't add it.!

Author

Commented:
ok i found an error in my nmbd log it says samba name server "my server" is now a local master browser for workgroup "my domai" on subnet "it's lxcbr0 ip address"
David FavorFractional CTO
Distinguished Expert 2018

Commented:
You must open port 22 for ssh access. Best to just keep port 22 open + install Fail2Ban to block any attacks.

Author

Commented:
the old dns entry stand for first to look. i remove it and restart smbd,... , it's working fine now. much better to access and no error on wbinfi -u or -g
but i still don't see in my domain master i try to add then it say it's exists .

Author

Commented:
yes but, what about fail2ban and nginx? [nginx-botsearch] set to 2 and i don't know what happend?
David FavorFractional CTO
Distinguished Expert 2018

Commented:
Best to close this question once it's answered, then open new questions for new topics... One topic per question.

You've asked many additional questions unrelated to logins. Each may have a long answer.

Open a new question for each of these topics.

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