[Sssd-maintainers] [Bug 1857104] New: Using FreeIPA breaks IPv4/IPv6 flags for SSH

https://bugzilla.redhat.com/show_bug.cgi?id=1857104

Bug ID: 1857104
           Summary: Using FreeIPA breaks IPv4/IPv6 flags for SSH
           Product: Fedora
           Version: 32
            Status: NEW
         Component: sssd
          Assignee: [e-mail]
          Reporter: [e-mail]
        QA Contact: [e-mail]
                CC: [e-mail], [e-mail],
                    [e-mail], [e-mail],
                    [e-mail], [e-mail],
                    [e-mail], [e-mail],
                    [e-mail],
                    [e-mail]
  Target Milestone: ---
    Classification: Fedora

Description of problem:
If a client is configured using ipa-client-install then the -4 and -6 flags
stop working for ssh.

Version-Release number of selected component (if applicable):
Doesn't matter. Seen on RHEL 6 through 8, and on current Fedora.

How reproducible:
100%

Steps to Reproduce:
1. ipa-client-install
2. ssh -4 host.example.com

Actual results:
Connected via IPv6

Expected results:
Connected via IPv4

Additional info:
The bug is that sss_ssh_knownhostsproxy is configured on the client and that
command doesn't respect the flags given to ssh.

The issue affects all hosts, not just those part of the same FreeIPA domain.

A practical effect of this is that connections get rejected or misbehave
because of IP based rules in place for this connection.