The sshd 3.4p1 (redhat8) servers are causing me long delays in login
(~10 sec). These sshd do not have UseDNS param, they have
VerifyReverseMapping param though.

I'd like to know whether the delays come reverse dns or from
something else.
The VerifyReverseMapping is 'no', and these old servers do not
have the UseDNS parameter.
The VerifyReverseMapping=no would mean that server shall not do
reverse-dns lookups, no ?

How can I remove login delays in these servers ?