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> Chapter 9 - Firewall > Building firewall objects and policies > Example: DoS Policy

Example: DoS policy

The company wishes to protect against Denial of Service attach. They have chosen some where they wish to block the attacks of the incidence goes above a certain threshold and for some others they are just trying to get a baseline of activity for those types of attacks so they are letting the traffic pass through without action.

  • The interface to the Internet is on WAN1
  • There is no requirement to specify which addresses are being protected or protected from.
  • The protection is to extend to all services.
  • The TCP attacks are to be blocked
  • The UDP, ICMP, and IP attacks are to be recorded but not blocked.
  • The tcp_syn_flood attach’s threshold is to be changed from the default to 1000
  1. Go to Policy & Objects > Policy > DoS.
  2. Create a new policy
  3. Fill out the fields with the following information:
Incoming Interface wan1
Source Address all
Destination Addresses all
Service ALL
Anomalies
Name Status Logging Action Threshold
tcp_syn_flood enabled enabled Block 1000
tcp_port_scan enabled enabled Block <default value>
tcp_src_session enabled enabled Block <default value>
tcp_dst_session enabled enabled Block <default value>
udp_flood enabled enabled Pass <default value>
udp_scan enabled enabled Pass <default value>
udp_src_session enabled enabled Pass <default value>
udp_dst_session enabled enabled Pass <default value>
icmp_flood enabled enabled Pass <default value>
icmp_sweep enabled enabled Pass <default value>
icmp_src_session enabled enabled Pass <default value>
icmp_dst_session enabled enabled Pass <default value>
ip_src_session enabled enabled Pass <default value>
ip_dst_session enabled enabled Pass <default value>
sctp_flood not enabled not enabled Pass <default value>
sctp_scan not enabled not enabled Pass <default value>
sctp_src_session not enabled not enabled Pass <default value>
sctp_dst_session not enabled not enabled Pass <default value>
  1. Toggle the button next to Enable this policy to ON.
  2. Select OK.
  3. Enter the following CLI command:

config firewall DoS-policy

edit 0

set status enable

set interface ''

config anomaly

edit "tcp_syn_flood"

set status enable

set log enable

set action block

set threshold 1000

next

edit "tcp_port_scan"

set status enable

set log enable

set action block

next

edit "tcp_src_session"

set status enable

set log enable

set action block

next

edit "tcp_dst_session"

set status enable

set log enable

set action block

next

edit "udp_flood"

set status enable

set log enable

next

edit "udp_scan"

set status disable

set status enable

set log enable

next

edit "udp_src_session"

set status enable

set log enable

next

edit "udp_dst_session"

set status enable

set log enable

next

edit "icmp_flood"

set status enable

set log enable

next

edit "icmp_sweep"

set status enable

set log enable

next

edit "icmp_src_session"

set status enable

set log enable

next

edit "icmp_dst_session"

set status enable

set log enable

next

edit "ip_src_session"

set status enable

set log enable

next

edit "ip_dst_session"

set status enable

set log enable

next

end

next

end