[Samba] Unable to net ads join samba to an active directory domain Failed to join domain: failed to connect to AD: Can't contact LDAP server

[Michael Evans]

> -----Original Message-----
> From: samba [mailto:samba-bounces at lists.samba.org] On Behalf Of
> Michael Evans via samba
> Sent: Sunday, November 21, 2021 9:59 PM
> To: 'Rowland Penny'
> Cc: samba at lists.samba.org
> Subject: Re: [Samba] Unable to net ads join samba to an active directory
> domain Failed to join domain: failed to connect to AD: Can't contact LDAP
> server
> 

It was an MTU issue.

I must have considered the vexing issue when trying to relax.  I suddenly
had an idea and investigated it.  Some google searches revealed that the
traceroute --mtu command would be the easiest way of diagnosing an MTU
issue. The maximum jumboframe size had been decreased since the VM setup
scripts were last customized.  Hence why the servers were never responding,
the packets were being dropped between VMs.

MTU issues are quite frustrating as the normal tests are all small packets.

The initial IPv6 setup did join correctly, though it preferred talking over
IPv4 first.

As expected for manually added DNS entries with static IPs, the
'DoDNSUpdate' portion failed.


Thank you for all of the help.