Enabling sending ICMPv6 time exceeded messages
A device sends out an ICMPv6 Time Exceeded message in the following situations:
If a received IPv6 packet's destination IP address is not a local address and its hop limit is 1, the device sends an ICMPv6 Hop Limit Exceeded message to the source.
Upon receiving the first fragment of an IPv6 datagram with the destination IP address being the local address, the device starts a timer. If the timer expires before all the fragments arrive, an ICMPv6 Fragment Reassembly Timeout message is sent to the source.
If large quantities of malicious packets are received, the performance of a device degrades greatly because it must send back ICMP Time Exceeded messages. You can disable sending ICMPv6 Time Exceeded messages.
To enable sending ICMPv6 time exceeded messages:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enable sending ICMPv6 Time Exceeded messages. | ipv6 hoplimit-expires enable | Optional. Enabled by default. |