Displaying Statistics Due Dos Attacks - Dell PowerConnect B-RX Configuration Manual

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The TCP security enhancement is enabled by default. To disable it, refer to
security enhancement"
Protecting against a blind injection attack
In a blind TCP injection attack, a perpetrator tries to inject or manipulate data in a TCP connection.
To reduce the chances of a blind injection attack, perform an additional check on all incoming TCP
segments.
This TCP security enhancement is enabled by default. To disable it, refer to
security enhancement"
Disabling the TCP security enhancement
The TCP security enhancement is automatically enabled. If necessary, you can disable this feature.
When you disable this feature, the device reverts to the original behavior.
To disable the TCP security enhancement, enter the following command at the Global CONFIG level
of the CLI.
BigIron RX(config)# no ip tcp tcp-security
To re-enable the TCP security enhancement once it has been enabled, enter the following
command.
BigIron RX(config)# ip tcp tcp-security
Syntax: [no] ip tcp tcp-security

Displaying statistics due DoS attacks

To display information about ICMP and TCP SYN packets dropped, passed, and block because burst
thresholds were exceeded.
BigIron RX(config-if-e1000-3/5)# show statistics dos-attack
Collecting transit DOS attack statistic for port 3/5...
------ DOS Attack Prevention Statistics ------
Port
-----
3/5
The display shows the following.
BigIron RX Series Configuration Guide
53-1001986-01
If the SYN bit is set and the sequence number is an exact match to the next expected
sequence, the device sends an ACK segment to the peer. Before sending the ACK segment, the
software subtracts one from the value being acknowledged.
If the SYN bit is set and the sequence number is acceptable, the device sends an
acknowledgement (ACK) segment to the peer.
on page 981.
on page 981.
Packet Drop Count
-----------------
12479732
Displaying statistics due DoS attacks
Packet Pass Count
------------------
436372
"Disabling the TCP
"Disabling the TCP
Completed successfully.
Port Block Count
----------------
232
34
981