This topic describes how to configure detection of a
UDP port scan attack.
These attacks scan the target IP addresses for open, listening,
or responsive services by targeting multiple protocols or ports on
one or more target IP address using obvious (sequentially numbered)
patterns of the target protocol or port numbers. The patterns are
derived by randomizing the protocol or port numbers and randomizing
the time delays between the transmissions.
To enable detection of a UDP port scan attack:
- Configure interfaces and assign an IP address to interfaces.
[edit]
user@host# set interfaces ge-0/0/1 unit 0 family inet address 192.0.2.0/24
user@host# set interfaces ge-0/0/3 unit 0 family inet address 198.51.100.0/24
- Configure security zones
trustZone and untrustZone and assign interfaces to them.[edit]
user@host# set security zones security-zone trustZone host-inbound-traffic system-services all
user@host# set security zones security-zone trustZone host-inbound-traffic protocols all
user@host# set security zones security-zone trustZone interfaces ge-0/0/1.0
user@host# set security zones security-zone untrustZone host-inbound-traffic system-services all
user@host# set security zones security-zone untrustZone host-inbound-traffic protocols all
user@host# set security zones security-zone untrustZone interfaces ge-0/0/3.0
- Configure security policies from
untrustZone to trustZone.[edit]
user@host# set security policies from-zone untrustZone to-zone trustZone policy policy1 match source-address any
user@host# set security policies from-zone untrustZone to-zone trustZone policy policy1 match destination-address any
user@host# set security policies from-zone untrustZone to-zone trustZone policy policy1 match application any
user@host# set security policies from-zone untrustZone to-zone trustZone policy policy1 then permit
user@host# set security policies default-policy deny-all
- Configure security screens and attach them to
untrustZone.[edit]
user@host# set security screen ids-option untrustScreen udp port-scan
user@host# set security screen ids-option untrustScreen alarm-without-drop
user@host# set security zones security-zone untrustZone screen untrustScreen
- Configure syslog.
[edit]
user@host# set system syslog file syslog any any
user@host# set system syslog file syslog archive size 10000000
user@host# set system syslog file syslog explicit-priority
user@host# set system syslog file syslog structured-data
user@host# set security policies from-zone untrustZone to-zone trustZone policy policy1 then log session-init
user@host# set security policies from-zone untrustZone to-zone trustZone policy policy1 then log session-close
- Commit the configuration.
