ESR series service routers.ESR-Series. User manual
Step Description Command Keys
14 Enable blocking of TCP packets, with 
all flags or with the set of flags: FIN, 
PSH, URG. The given command 
provides the protection against XMAS 
attack.
esr(config)# ip firewall screen 
spy-blocking tcp-all-flag
15 Enable blocking of TCP packets, with 
the zero 'flags' field.
esr(config)# ip firewall screen 
spy-blocking tcp-no-flag
16 Enable blocking of fragmented ICMP 
packets.
esr(config)# ip firewall screen 
suspicious-packets icmp-
fragment
17 Enable blocking of fragmented IP 
packets.
esr(config)# ip firewall screen 
suspicious-packets ip-fragment
18 Enable blocking of ICMP packets 
more than 1024 bytes.
esr(config)# ip firewall screen 
suspicious-packets icmp-
fragment
19 Enable blocking of fragmented TCP 
packets, with the SYN flag.
esr(config)# ip firewall screen 
suspicious-packets syn-
fragment
20 Enable blocking of fragmented UDP 
packets.
esr(config)# ip firewall screen 
suspicious-packets udp-
fragment
21 Enable blocking of packets with the 
protocol ID contained in IP header 
equal to 137 and more.
esr(config)# ip firewall screen 
suspicious-packets unknown-
protocols
22 Set the frequency of notification (via 
SNMP, syslog and in CLI) of detected 
and blocked network attacks.
esr(config)# ip firewall logging 
interval <NUM>
<NUM> – time interval in seconds 
[30 .. 2147483647]
23 Enable more detailed message output 
about detected and blocked network 
attacks in the CLI.
esr(config)# logging firewall 
screen detailed
24 Enable mechanism of DoS attacks 
detection and logging via CLI, syslog 
and SNMP.
esr(config)# logging firewall 
screen dos-defense 
<ATACK_TYPE>
<ATACK_TYPE> – DoS attack type, 
takes the following values: icmp-
threshold, land, limit-session-
destination, limit-session-source, 
syn-flood, udp-threshold, winnuke.