print "Enter the Tunnel Interface IP "; $tunip = <>; chomp ($tunip); $test2 = check_valid_ip2($tunip); print "\n"; my $period="."; my @ip_fields = split(/\./, $tunip); open (LASTOCTET, ">lastoctet"); print LASTOCTET "$ip_fields[3]\n"; close (LASTOCTET); open (MYINPUTFILE, "lastoctet"); while () { my($line) = $_; chomp($line); $ipcheck = $line; } close (MYINPUTFILE); if ($ipcheck % 2) { $test_ip=$ipcheck+1; } else { $test_ip=$ipcheck-1; } $bgpip = $ip_fields[0].$period.$ip_fields[1].$period.$ip_fields[2].$period.$test_ip;