#!/usr/bin/perl
use strict;
use warnings;

while (<DATA>) {
    next if /^\d{4}\s/; # A million ways to do this, but it depends what the rest of your data looks like
    print;
}

__DATA__
2345      IP   NAME.com         STATUS IPADDRESS1
2345/1243 IP Name-interface.com STATUS IPADDRESS2
2345/3213 IP NAME-interfce2.com STATUS IPADDRESS1
2345/1212 IP Name-interface3.com STATUS IPADDRESS3
4321      IP   CNAME.com         STATUS IPADDRESS_1
4321/1643 IP CName-interface.com STATUS IPADDRESS_1
4321/3673 IP CNAME-interfce2.com STATUS IPADDRESS_2