Disabling Forwarding Icmp Fragments; Configuring Rate Limit For Icmp Error Messages; Specifying The Source Address For Icmp Packets - HPE FlexNetwork HSR6800 Configuration Manual

To prevent such problems, you can disable the device from sending ICMP error messages. A device
that is disabled from sending ICMP time exceeded messages does not send ICMP TTL exceeded in
transit messages. However, it can still send ICMP fragment reassembly time exceeded messages.

Disabling forwarding ICMP fragments

Disabling forwarding ICMP fragments can protect your device from ICMP fragments attacks.
To disable forwarding ICMP fragments:
Step
1. Enter system view.
2. Disable forwarding ICMP fragments.

Configuring rate limit for ICMP error messages

To avoid sending excessive ICMP error messages within a short period that might cause network
congestion, you can limit the rate at which ICMP error messages are sent. A token bucket algorithm
is used with one token representing one ICMP error message.
A token is placed in the bucket at intervals until the maximum number of tokens that the bucket can
hold is reached.
A token is removed from the bucket when an ICMP error message is sent. When the bucket is empty,
ICMP error messages are not sent until a new token is placed in the bucket.
To configure rate limit for ICMP error messages:
Step
1. Enter system view.
2. Set the bucket size and
the interval for tokens to
arrive in the bucket for
ICMP error messages.

Specifying the source address for ICMP packets

Perform this task to specify the source IP address for outgoing ping echo request and ICMP error
messages. As a best practice, specify the IP address of the loopback interface as the source IP
address. This feature helps users to locate the sending device easily.
If you specify an IP address in the ping command, ping echo requests use the specified address as
the source IP address rather than the IP address specified by the ip icmp source command.
To specify the source IP address for ICMP packets:
Step
1. Enter system view.
Command
system-view
ip icmp fragment
discarding
Command
system-view
ip icmp error-interval interval
[ bucketsize ]
Command
system-view
191
Remarks
N/A
By default, forwarding ICMP
fragments is enabled.
Remarks
N/A
By default, the bucket allows a
maximum of 10 tokens. A token is
placed in the bucket at an interval of 100
milliseconds.
To disable the ICMP rate limit, set the
interval to 0 milliseconds.
Remarks
N/A