Configuring UDP Port Scan Attack Screen
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 192.0.2.0/24user@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 alluser@host# set security zones security-zone trustZone host-inbound-traffic protocols alluser@host# set security zones security-zone trustZone interfaces ge-0/0/1.0user@host# set security zones security-zone untrustZone host-inbound-traffic system-services alluser@host# set security zones security-zone untrustZone host-inbound-traffic protocols alluser@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 anyuser@host# set security policies from-zone untrustZone to-zone trustZone policy policy1 match destination-address anyuser@host# set security policies from-zone untrustZone to-zone trustZone policy policy1 match application anyuser@host# set security policies from-zone untrustZone to-zone trustZone policy policy1 then permituser@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-scanuser@host# set security screen ids-option untrustScreen alarm-without-dropuser@host# set security zones security-zone untrustZone screen untrustScreen
- Configure syslog.[edit]user@host# set system syslog file syslog any anyuser@host# set system syslog file syslog archive size 10000000user@host# set system syslog file syslog explicit-priorityuser@host# set system syslog file syslog structured-datauser@host# set security policies from-zone untrustZone to-zone trustZone policy policy1 then log session-inituser@host# set security policies from-zone untrustZone to-zone trustZone policy policy1 then log session-close
- Commit the configuration.[edit]user@host# commit