#!/usr/bin/perl
use strict;
use warnings;
use feature 'say';
use Data::Dumper;

while (<>) {
    chomp;
    if (/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/) {
	my @tmp = split /\s+/;
	# print Dumper \@tmp;
	say $tmp[0];
    }
}

__END__

$ perl test.pl in.txt
1.1.1.1:0

##</code><code>##


==============================================================================
LDP Sessions
==============================================================================
Peer LDP Id        Adj Type   State         Msg Sent  Msg Recv  Up Time
------------------------------------------------------------------------------
------------------------------------------------------------------------------
No Matching Entries Found
==============================================================================

==============================================================================
LDP IPv4 Sessions
==============================================================================
Peer LDP Id         Adj Type  State         Msg Sent  Msg Recv  Up Time
------------------------------------------------------------------------------
1.1.1.1:0     Targeted  Established   822443    822431    273d 15:02:20
------------------------------------------------------------------------------
No. of IPv4 Sessions: 1
==============================================================================

##</code><code>##


#!/usr/bin/perl
use strict;
use warnings;
use feature 'say';

my $output1 = "==============================================================================
LDP Sessions
==============================================================================
Peer LDP Id        Adj Type   State         Msg Sent  Msg Recv  Up Time
------------------------------------------------------------------------------
------------------------------------------------------------------------------
No Matching Entries Found
==============================================================================";

my $output2 = "==============================================================================
LDP IPv4 Sessions
==============================================================================
Peer LDP Id         Adj Type  State         Msg Sent  Msg Recv  Up Time
------------------------------------------------------------------------------
1.1.1.1:0     Targeted  Established   822443    822431    273d 15:02:20
------------------------------------------------------------------------------
No. of IPv4 Sessions: 1
==============================================================================";

say 'Found 1: ' . $output1 if $output1 =~ (/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/);
say 'Found 2: ' . $output2 if $output2 =~ (/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/);

__END__

$ perl test.pl
Found 2: ==============================================================================
LDP IPv4 Sessions
==============================================================================
Peer LDP Id         Adj Type  State         Msg Sent  Msg Recv  Up Time
------------------------------------------------------------------------------
1.1.1.1:0     Targeted  Established   822443    822431    273d 15:02:20
------------------------------------------------------------------------------
No. of IPv4 Sessions: 1
==============================================================================