North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: ICMP Blocking Woes
Lo! On Thu, 2 Oct 2003, Sean Donelan did sayeth: > Various ISPs have been trying lots of different ICMP filters. You can > see some of the impact on the Internet average graphs from XAffire. > > http://www.xaffire.com/press/ea/EA20030902_images?rf=EM005 > > Xaffire/Matrix Systems apparently used ping packets that were the > same size as those being filtered by some ISPs. According to Xaffire > service providers implementing filters included Cable & Wireless and > Level 3. It does raise the question of whether ICMP Echo is a good mechanism for monitoring systems that are across third party networks. I personally think that filtering ICMP is becoming less useful and you would get better results using other probe methods eg SYN/RST as deployed by numerous port scanning tools eg nmap Steve
|