ICMP is the internet control access protocol . ICMP is the plrotocol that should be allowed when not able to ping a remote device residing behind a firewall. ICMP is the protocol of network layer.
Check your local system's firewall for blocking of ICMP (ping) traffic.
Because ICMP traffic, notably ICMP ECHO REQUEST-0 and ECHO REPLY-8 are used in network diagnostic sequences.
ICMP
Add a firewall rule to allow ICMP from WAN. Firewall | Rules | Add Action - Pass Interface - WAN Protocol - ICMP ICMP type - Any (or echo reply) Source - Any If your WAN is a private subnet, you will need to disable block private networks on the Interfaces | WAN page
As Admin In Command prompt, type: netsh firewall set icmpsetting 8 enable Enter
inet
it could be a firewall blocking icmp outbound traffic from said machine, if the machine can still access network functions such as the internet and lan printers its tcpip stack is still intact it could be a firewall blocking icmp outbound traffic from said machine, if the machine can still access network functions such as the internet and lan printers its tcpip stack is still intact.
Pretty much every protocol used for malicious traffic and Trojans is also used for legitimate traffic. You cannot block all bad traffic just by filtering on protocols. When given that ICMP and HTTP are both allowed, if you have to block one, block ICMP. Choices were: DNS DHCP ICMP HTTP https://library.skillport.com/courseware/cbtlib/TPSY0201/metadata/eng/TPSY0201B.htm?
To handle error messages when a message does not reach it's destination. To announce timeouts and network congestion.
There really is no "port" for icmp but there is a icmp code. If you are looking for the icmp code for echo-reply it is 0 and the echo is 8 For an access list you could do the following: permit icmp any any echo-reply permit icmp any any echo Or the same using the icmp code permit icmp any any 0 permit icmp any any 8
As promiscuous mode can be used in a malicious way to sniff on a network, one might be interested in detecting network devices that are in promiscuous mode. In promiscuous mode, some software might send responses to frames even though they were addressed to another machine. However, experienced sniffers can prevent this (e.g., using carefully designed firewall settings). An example is sending a ping (ICMP echo request) with the wrong MAC address but the right IP address. If your firewall blocks all ICMP traffic, this will be prevented.