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ICMP Destination Unreachable (by Tony Fortunato)

Tony_fortunatoThe_tech_firmAuthor Profile - Tony Fortunato is a Senior Network Specialist with experience in design, implementation, and troubleshooting of LAN/WAN/Wireless networks, desktops and servers since 1989. His background in financial networks includes design and implementation of trading floor networks. Tony has taught at local high schools, Colleges/Universities, Networld/Interop and many onsite private classroom settings to thousands of analysts. Tony is an authorized and certified Fluke Networks and Wireshark Instructor. His Pine Mountain Group CNA Level I and II certification demonstrates his vendor neutral approach to network design, support and implementations. Tony has architected, installed and supported various types of Residential Wireless High Speed as well as hundreds of WIFI hotspots. Tony uses a variety of technologies from Powerline, Wireless and wired technologies to find the most cost-efficient and reliable solution for his customers. Tony combines custom programs, open source and commercial software to ensure a simple support infrastructure.

In this chat I explain how some implementations of DHCP relay or helper, can cause a flurry of these ICMP messages.

The worst case scenario I have seen is where the DHCP server was so busy sending these ICMP packets, it could not properly assign an IP address.


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