ICMP ECHO REPLY packets received that were not solicited


The arrival of ICMP echo reply packets does not correspond to sent ECHO packets.

Recommended action

On the Sequencer machine, stop any ping programs or any other programs that are sending ICMP ECHO packets.

Detailed explanation

An ICMP echo reply packet (ICMP type 0) was received for which no corresponding ECHO request packet (ICMP type 8) had been sent. This is likely due to some other process on the source host sending ICMP ECHO packets.

Unlike TCP or UDP protocols, ICMP ECHO requests do not contain information that ties the request to a specific application. Therefore, if multiple programs within one machine are sending ECHO requests, it is difficult for the stack to decide which application should receive an ICMP echo reply. In this case, the stack will send the reply to all applications that are listening to ICMP ECHO replies. When a Sequencer receives an echo reply that is not associated with an ECHO request that it sent, it generates this message.

Possible secondary messages

  • "Some other process may be sending ECHO packets from the Sequencer host" </ul>

    Other resources

    RFC 792