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Questions tagged [icmp]

ICMP stands for Internet Control Message Protocol. It is primarily used by the operating systems of networked computers to send error messages indicating service status.

ICMP is not normally used by end-users or to send messages. It's main use is in diagnostics and checking that the network is functioning correctly.

ICMP is just one communications protocol on the web. Others include:

  • Transmission Control Protocol (TCP)
  • User Datagram Protocol (UDP)
  • Hypertext Transfer Protocol (HTTP)
  • Post Office Protocol (POP3)
  • File Transfer Protocol (FTP)
  • Internet Message Access Protocol (IMAP)

ICMP on Wikipedia

127 questions
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Why am I having trouble using ptunnel to connect to machine in DMZ from WAN?

I'm trying to have a play with ptunnel, I have it running (listening) on my raspberry pi in my DMZ and I can connect to it from my LAN and tunnel ssh over it, but I can't get it to work over my LAN. I have tried connecting from work and also from my…
Grezzo
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How to create ICMP Code-3 error

I made lots of search but couldn't find useful info about how create ICMP Code-3 (dest. unreachable) error and capture it with Wireshark. I tried to ping a closed port in Linux machine and also used host command but nothing. Could anyone help me…
ebyrock
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