Each of the 2 lines where you test against the regex is reading another record. Don't do that. Instead, you could store the record in a variable and then do the two tests on that one variable. eg:

use strict;
use warnings;
my $ip = "";

while (<>) {
    if (/Relay.access.denied/) {
        my $rec;

        do {
            $rec = <>;
            print "$2\n" if $rec =~ /(\d+)\s+(\S+)/;
            $ip = $2;
        } until ($rec !~ /(\d+)\s+(\S+)/);
    }
}

[download]

However, there are so many other ways to approach this too. It would be better to avoid the regex duplication in the first place, for example.

Addendum: As you appear to be trying to parse the output of pflogsumm, perhaps this is an XY problem?

In reply to Re: Loop problem: jumps one record by hippo
in thread Loop problem: jumps one record by Anonymous Monk

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