1.11 ICMP 2/3
–Congestion
control: when datagrams are dropped because of
buffer overflow, a source quench message is sent.
–Route-change
information: when a router realizes that a host should
be using a different router to reach a destination it sends a message with the updated
routing information.
–Performance
measuring: a network manager can check the time it takes to send datagrams to
particular locations.
–Subnet
addressing: a host can request for the subnet mask of its
local network from the router.