Please enable JavaScript.
Coggle requires JavaScript to display documents.
Module 13 - Coggle Diagram
Module 13
ICMP Messages
ICMPv4 is the messaging protocol for IPv4. ICMPv6 is the messaging protocol for IPv6 and includes additional functionality.
-
Internet Control Message Protocol (ICMP) provides feedback about issues related to the processing of IP packets under certain conditions.
Note: ICMPv4 messages are not required and are often not allowed within a network for security reasons.
-
ICMPv6 Messages
ICMPv6 has new features and improved functionality not found in ICMPv4, including four new protocols as part of the Neighbour Discovery Protocol (ND or NDP)
Messaging between an IPv6 router and an
IPv6 device, including dynamic address allocation are as follows:
-
Messaging between IPv6 devices, including
duplicate address detection and address resolution are as follows:
-
Ping – Test Connectivity
The ping command is an IPv4 and IPv6 testing utility that uses ICMP echo request and echo reply messages to test connectivity between hosts and provides a summary that includes the success rate and average round-trip time to the destination.
If a reply is not received within the timeout, ping provides a message indicating that a response was not received.
It is common for the first ping to timeout if address
resolution (ARP or ND) needs to be performed
before sending the ICMP Echo Request.
-
-
Time Exceeded
When the Time to Live (TTL) field in a packet is decremented to 0, an ICMPv4 Time Exceeded message will be sent to the source host.
ICMPv6 also sends a Time Exceeded message. Instead of the IPv4 TTL field, ICMPv6 uses the IPv6 Hop Limit field to determine if the packet has expired.
Ping a Remote Host
-
A local host can ping a host on a remote network. A successful ping g across the internetwork confirms communication on the local network
-