2021年7月26日 · ICMP is indicated in the IP header "protocol type" number 1 (as TCP=6 and UDP=17, while ICMPv6=58). ICMP also allows extra payload than just the message itself for various message types. Also, conventional naming systems designates "Layer 3" for IP and "Layer 4" for ICMP/TCP/UDP.

ICMP (ping, trace)is a layer 3 protocol suite within the TCP/IP suite, doesnt test any layer 4 or above functions, therefore, it has no TCP/UDP layer 4 port number. The sub protocols within it do. You can block echo replies by closing port 7.

2019年3月3日 · I agree with Rolf Fischer. It seems questions about icmp having port numbers are recurrent. Check out these links for mote details:

2012年4月21日 · At the same time on ICMP requests/response After NAT is shown that the Identifier of the clashing ICMP session is changed to 0 by the NAT, and is incremented from there on. As a summary it can be said that the Linux NAT handles the clashing of ICMP identifiers on its on (As the ICMP identifiers are not changed before the NAT).

2009年6月10日 · The Internet Control Message Protocol (ICMP) is a network-layer Internet protocol that provides message packets to report errors and other information regarding IP packet processing back to the source. ICMP is documented in RFC 792.The version of ICMP for Internet Protocol version 4 is also known as ICMPv4, as it is part of IPv4.

2016年6月14日 · What is protocol 1 port XXX in this context. Protocol number 1 is ICMP. ICMP doesn't use ports but it uses a 16-bit identifier that is referred to as port here for simplicity. (Perhaps the programmer couldn't be bothered to make the distinction or users would be more confused by an identifier label.)

2022年12月8日 · So the port numbers reported by Wireshark aren't for the ICMP packet itself but for its payload (i.e. the original TCP packet that caused this error). (Wireshark dissects the payload as a nested IP packet so that you could see the information, but it cannot distinguish the "depth" of the dissected fields, so the entire captured packet receives ...

2020年3月24日 · the icmp pings are sent to the destination on port 25. Mar 11 2020 16:04:35: %ASA-6-302021: Teardown ICMP connection for faddr 10.35.104.12/0 gaddr 10.50.11.200/25 laddr 10.50.11.200/25 . But I did a packet capture and saw the same packets and I couldn't see the any information about port because obviously ICMP doesn't support ports.

2019年3月6日 · Within ICMP there is a message type for echo-request and a message type for echo-reply. So if you want to have an access list statement for ping it might look something like this: ip access-list 101 permit icmp any any eq echo-request. ip access-list 101 permit icmp any any eq echo-reply

2008年10月10日 · ACL's are processed line by line from the start and your first line is denying icmp from anywhere. Note that icmp on it's own covers echo and echo-reply. You need to rewrite your access-list to . access-list 110 permit icmp host 10.10.1.1 any . access-list 110 permit icmp host 10.10.1.1 any echo-reply . access-list 110 permit icmp host 10.10.1 ...