Yes, it is (especially UDP). Many networks still don&#x27;t filter properly.<p><i></i><i>&quot;The solution to this problem, described in RFC2827, which was written some 13 years ago by Paul Ferguson and Daniel Senie, is to block IP packets entering the internet which have source IP addresses which are forged...&quot;</i><i></i><p><a href="http:&#x2F;&#x2F;tools.ietf.org&#x2F;html&#x2F;rfc2827.html" rel="nofollow">http:&#x2F;&#x2F;tools.ietf.org&#x2F;html&#x2F;rfc2827.html</a><p><a href="http:&#x2F;&#x2F;www.bcp38.info&#x2F;index.php&#x2F;Main_Page" rel="nofollow">http:&#x2F;&#x2F;www.bcp38.info&#x2F;index.php&#x2F;Main_Page</a>