Hi,
I am glad to hear you never found anything.

Currently I see the issue in the midst of a long provisioning script.

My three lines of script are accurate in-so-far as within my
provisioning iptables are modified with "sudo apt-get install -yq
samba"

I will shrink down my provisioning script to see what arises.
I will get back to you.

PS: you said you installed samba 2:4.11.6+dfsg-0ubuntu1.6

As I posted in my original message, when I run "samba --version" I get this...
Version 4.11.6-Ubuntu



On 30/03/2021, Steve Beattie <email address hidden> wrote:
> Hello, sorry you are having this issue.
>
> Unfortunately I am unable to reporduce this, with samba 2:4.11.6+dfsg-
> 0ubuntu1.6 from focal, either by applying iptables rules manually or
> enabling firewall rules with ufw:
>
>   $ sudo iptables -D INPUT -i lo -j LOG
>   $ sudo iptables -L INPUT -n
>   Chain INPUT (policy ACCEPT)
>   target     prot opt source               destination
>   LOG        all  --  0.0.0.0/0            0.0.0.0/0            LOG flags 0
> level 4
>   $ sudo apt install samba
>     [ELIDED]
>   $ sudo iptables -L INPUT -n
>   Chain INPUT (policy ACCEPT)
>   target     prot opt source               destination
>   LOG        all  --  0.0.0.0/0            0.0.0.0/0            LOG flags 0
> level 4
>
> What are you using to apply firewall rules? None of the samba packages
> directly manipulate iptables in their postinstall scripts or in their
> service startup files that I can see. The samba package does drop an
> application file for ufw in /etc/ufw/applications.d/samba, but if ufw is
> not enabled, this should not be applied, nor should the ufw trigger that
> runs at the end of the installation touch iptables settings.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1921941
>
> Title:
>   samba install flushes iptables and sets all chains to policy accept
>
> Status in samba package in Ubuntu:
>   New
>
> Bug description:
>   I have been tracking down why my iptables have been getting flushed in
>   a VM.
>
>   This is what it lead me to...
>
>   sudo iptables -L -n
>   sudo apt-get install -yq samba
>   sudo iptables -L -n
>
>   The iptables listing before the samba install is long.
>
>   The iptables listing after the samba install have been flushed and all
>   chains are set to policy ACCEPT!
>
>   Ubuntu 20.04.2
>
>   samba --verision
>   Version 4.11.6-Ubuntu
>
>   ProblemType: Bug
>   DistroRelease: Ubuntu 20.04
>   Package: samba 2:4.11.6+dfsg-0ubuntu1.6
>   ProcVersionSignature: Ubuntu 5.4.0-70.78-generic 5.4.94
>   Uname: Linux 5.4.0-70-generic x86_64
>   ApportVersion: 2.20.11-0ubuntu27.16
>   Architecture: amd64
>   CIFSMounts:
>    /mnt/v      //192.168.1.5/picasso_digital                          cifs
> ro,relatime,vers=3.02,cache=strict,username=picassoUSER,uid=0,noforceuid,gid=0,noforcegid,addr=192.168.1.5,file_mode=0755,dir_mode=0755,soft,nounix,serverino,mapposix,rsize=4194304,wsize=4194304,bsize=1048576,echo_interval=60,actimeo=1
>    /mnt/pshare //192.168.1.5/pshare/picasso.digital[/picasso.digital] cifs
> rw,relatime,vers=3.02,cache=strict,username=picassoUSER,uid=0,noforceuid,gid=0,noforcegid,addr=192.168.1.5,file_mode=0755,dir_mode=0755,soft,nounix,serverino,mapposix,rsize=4194304,wsize=4194304,bsize=1048576,echo_interval=60,actimeo=1
>   CasperMD5CheckResult: skip
>   Date: Tue Mar 30 14:18:30 2021
>   InstallationDate: Installed on 2021-03-30 (0 days ago)
>   InstallationMedia:
>
>   SambaClientRegression: Yes
>   SourcePackage: samba
>   UpgradeStatus: No upgrade log present (probably fresh install)
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/ubuntu/+source/samba/+bug/1921941/+subscriptions
>