Configuring ICMP properties

Procedure

1. Run system-view

   The system view is displayed.

2. Run icmp-reply fast

   The fast ICMP reply function is enabled.

   By default, the fast ICMP reply function is enabled on the device.

   After the fast ICMP reply function is enabled on the device, the local policy-based routing function does not take effect for ICMP packets. Therefore, if the local policy-based routing function is configured on the device, you are advised to disable the fast ICMP reply function.

3. Run icmp ttl-exceeded drop

   The device is configured to discard the ICMP packets whose TTL values are 1.

   By default, the function of discarding ICMP packets with TTL values 1 is disabled.

4. Run icmp with-options drop

   The device is configured to discard the ICMP packets that carry options.

   By default, the function of discarding ICMP packets that carry options is disabled.

5. Run icmp unreachable drop

   The function of discarding ICMP destination unreachable packets is enabled.

   By default, the function of discarding ICMP destination unreachable packets is disabled.

6. Run icmp port-unreachable send

   The function of sending ICMP port unreachable packets is enabled.

   The function of sending ICMP port unreachable packets is disabled.

7. Run icmp time-exceed { extension { compliant | non-compliant } | classic }

   The format of ICMP Time Exceeded packets is configured.

   By default, ICMP Time Exceeded packets carry extension headers in compliant mode and original datagrams are of variable length.

8. Run icmp blackhole unreachable send

   The BRAS is disabled from sending a Destination Unreachable ICMP packet to an initiator when a tracert packet matches an IPv4 blackhole route.

   By default, the BRAS is disabled from sending a Destination Unreachable ICMP packet to an initiator when a tracert packet matches an IPv4 blackhole route.

9. Run interface interface-type interface-number

   The interface view is displayed.

10. Run

    undo icmp ttl-exceeded send

    The function to send ICMP Time Exceeded messages is enabled.

    By default, an interface is enabled to send ICMP Time Exceeded messages.

11. Run icmp host-unreachable send

    The function of sending ICMP host unreachable packets is enabled.

    By default, the function of sending ICMP host unreachable packets is enabled.