I am using a Debian 6 - 64bit OS and my server is ddosed/flooded through udp protocol from time to time. I basically host game-servers and my firewall is set to rate-limit the packets on allowed ports but sometimes the rate per IP is low but the number of IPs are more so my server sends outgoing icmp unreachable replies to the attacking IP which does no benefit but chokes/saturates the port

ICMP Unreachable - Engineer Life Nov 09, 2016 networking - Is ICMP port unreachable error generated by ICMP Port unreachable is a code 3 within type 3 3.3. Port Unreachable - generated if the designated transport protocol (e.g., UDP) is unable to demultiplex the datagram in the transport layer of the final destination but has no protocol mechanism to inform the sender How to Fix This Destination Host Unreachable

Nov 22, 2009 · ip unreachable fragmentation-needed! enable or disable other ip unreachable messages per your own needs. On Cisco you cannot control the specific type of message on the interface level (yet). ip unreachables are configured as on or off. You can however limit what gets sent back to the source by applying extended ACL’s:

What is ICMP? The Protocol, Port Number and PING! Jan 15, 2020 Why ICMP Destination Port Unreachable error messeage is Barring server S doing something (like sending an ICMP Destination Port Unreachable) or the application on C stopping this transfer for some reason, it will continue to send 3 TB of data to S. S must still receive (and then discard) all this data. The ICMP Destination Port Unreachable prevents the majority of this data from ever being sent.

Jul 06, 2011

ICMP (Internet Control Message Protocol) R3 will reply with a type 3 destination unreachable message. Take a close look at the type and code. The type tells us the destination is unreachable. This could mean that the remote host or network is unreachable. However, the code is number 3 which means port unreachable. R3 uses this code because nothing is listening on UDP port 33435. Understanding IP Fragmentation. Fragmentation occurs when Oct 11, 2017