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Chapter 11. IP SLA > ICMP Operations
ICMP Operations
The Internet Control Message Protocol (ICMP) is also called a “ping test.” This is usually the first troubleshooting tool for a network operator to verify connectivity between two points in the network. The destination device can be any IP host. In ICMP operations, the source device sends several ICMP packets to the destination, which echoes the ICMP replies. ICMP operations should mainly be used to verify connectivity and for troubleshooting, because ICMP was not designed as an accurate delay measurement tool. Uncertainties can be caused by low priority processing of ICMP packets in routers, so the absolute delay results might not be representative of the actual packet delay of user traffic.
Note
Note that low-priority processing refers to the router receiving and originating ICMP packets, not to forwarding them. By default, routers forward ICMP packets with the same priority as any other traffic.
