R3303-HP HSR6800 Routers Security Configuration Guide

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An attacker sends a large number of UDP packets to the target in a short time, making the target
too busy to process normal services.
Blacklist function
The blacklist function is an attack protection measure that filters packets by source IP address. Compared
with Access Control List (ACL) packet filtering, blacklist filtering is simpler in matching packets and
therefore can filter packets at a high speed. Blacklist filtering is very effective in filtering packets from
certain IP addresses.
Working in conjunction with the scanning attack protection function or the user login authentication
function, the device can add blacklist entries automatically and can age such blacklist entries. More
specifically:
• When the device detects a scanning attack from an IP address according to the packet behavior, it
adds the IP address to the blacklist. Thus, packets from the IP address are filtered.
• When the device detects that an FTP, Telnet, SSH, SSL, or web user has failed to provide the correct
username, password, or verification code (for a web login user) after the maximum number of
attempts, it considers the user an attacker, adds the IP address of the user to the blacklist, and filters
subsequent login requests from the user. This mechanism can effectively prevent attackers from
cracking login passwords through repeated login attempts. The maximum number of login failures
is six, the blacklist entry aging time is 10 minutes, and they are not configurable.
The device also allows you to add and delete blacklist entries manually. Blacklist entries added manually
can be permanent blacklist entries or non-permanent blacklist entries. A permanent entry always exists in
the blacklist unless you delete it manually. You can configure the aging time of a non-permanent entry.
After the timer expires, the device automatically deletes the blacklist entry, allowing packets from the
corresponding IP address to pass.
Traffic statistics function
The traffic statistics function collects statistics on sessions between the internal network and external
network almost in real time. You can custom attack protection policies based on the statistics. For
example, by analyzing whether the total number of TCP or UDP session requests initiated from the
external network to the internal network exceeds the threshold, you can determine whether to limit new
sessions in the direction, or limit new sessions to a specific internal IP address.
The device supports collecting statistics on the following items:
• Total number of sessions
• Session establishment rate
• Number of TCP sessions
• Number of half-open TCP sessions
• Number of half-close TCP sessions
• TCP session establishment rate
• Number of UDP sessions
• UDP session establishment rate
• Number of ICMP sessions
• ICMP session establishment rate
• Number of RAW IP sessions