The default MTU on the VLANIF interface is 1500 bytes. When a router pings a directly connected S series switch, why packet loss occurs if the lengths of ping packets are shorter than 1500 bytes

An S series switch (a non-S1700 switch) sends a ping packet every second, while the high-end router sends ping packets at a shorter interval. When the router sends relatively long ping packets (for example, the lengths of ping packets are longer than 400 bytes), the number of bytes sent to the CPU every second exceeds the ICMP CAR value set on the switch. As a result, the ping packets are discarded by the switch. Therefore, when a router pings a directly connected S series switch (except the S1700), packet loss occurs if the lengths of ping packets are shorter than 1500 bytes.

Scroll to top