Fortinet IPS manual Configuring Icmp sweep protection

Page 58

Configuring ICMP sweep protection

ICMP sweep attacks

Configuring ICMP sweep protection

To configure the ICMP sweep anomaly protection settings

1Go to Intrusion Protection > DoS Sensor.

2Select Create New.

3Configure the options for icmp_sweep, icmp_src_session, and icmp_dst_session.

4Select OK.

Suggested settings for different network conditions

Enable or disable the ICMP predefined signatures depending on current network traffic and the network scanning tools being used.

To use the icmp_sweep anomaly, monitor the network to find out the normal ICMP traffic patterns. Configure the icmp_sweep anomaly threshold to be triggered when an unusual volume of ICMP requests occurs.

	FortiGate IPS User Guide Version 3.0 MR7
58	01-30007-0080-20080916

Image 58

Contents E R G U I D E Trademarks Contents DoS sensors Protocol decodersIPS sensors SYN flood attacksIntroduction FortiGate IPSDocument conventions About this documentFortinet documentation Typographic conventionsFortiGate Pptp VPN User Guide Fortinet Knowledge Center Customer service and technical supportComments on Fortinet technical documentation IPS settings and controls IPS overview and general configurationThis section contains the following topics Default fail open setting When to use IPSDefault signature and anomaly settings Config ips global Set fail-open enable disable endMonitoring the network and dealing with attacks Setting the buffer sizeConfiguring logging and alert email Controlling sessionsAttack log messages Signature Anomaly FortiGuard CenterAdding protection profiles to firewall policies Using IPS sensors in a protection profileCreating a protection profile that uses IPS sensors Select Create NewAdding protection profiles to user groups Using IPS sensors in a protection profile IPS predefined signatures Predefined signaturesViewing the predefined signature list Column SettingsEnable Clear All FiltersCreate a sensor and add IPS filters to it Viewing the predefined signature list IPS custom signatures Custom signaturesViewing the custom signature list Adding custom signatures using the CLI Custom signature configurationAdding custom signatures using the web-based manager Command syntax patternCustom signature fields Creating custom signaturesShows the valid characters for custom signature fields Name BufferOverflow Custom signature syntaxAttackid SrcportContent keywords Keyword and value Description Deprecated, see pattern and context keywords Pattern yahoo.com Pattern GETContext uri Context hostRegexdelimismxAEGRU PcreRegex/mdelim Uri !uristrProtocol tcp IP header keywords Keyword and Value DescriptionTCP header keywords Keyword and Value Description Tcpflags AP Tcpflags S,12Icmp keywords Keyword and Value Usage UDP header keywords Keyword and Value DescriptionOther keywords Keyword and Value Description Example custom signatures Example 1 signature to block access to example.comSbid --name Block.example.com Sbid --name Block.example.com Sbid --name Block.SMTP.VRFY.CMD Example 2 signature to block the Smtp ‘vrfy’ commandSbid --name Block.SMTP.VRFY.CMD --pattern vrfy Creating custom signatures Protocol decoders Protocol decodersUpgrading the IPS protocol decoder list Viewing the protocol decoder list Protocol decoder list Protocols Protocol decoder names PortIPS sensors AlldefaultAlldefaultpass Viewing the IPS sensor listProtectclient Configuring IPS sensorsAdding an IPS sensor ProtectemailserverIPS sensor attributes IPS sensor filtersIPS sensor overrides Configuring filtersReset Delete and Edit Delete or edit the filter IconsConfiguring pre-defined and custom overrides ApplicationExempt IP SourceDoS sensors Sequence in which the sensors examine network traffic Configuring DoS sensorsViewing the DoS sensor list Appears, and select OKName Enter or change the DoS sensor name Comments Anomaly configurationDoS sensor attributes Will appear in the DoS sensor listUnderstanding the anomalies Udpscan Anomaly Description TcpdstsessionUdpflood UdpsrcsessionUnderstanding the anomalies SYN flood attacks What is a SYN flood attack?How SYN floods work FortiGate IPS Response to SYN flood attacks What is SYN threshold?What is SYN proxy? How IPS works to prevent SYN floodsIPS operation before synflood threshold is reached Suggested settings for different network conditions Configuring SYN flood protectionConfigure the options for tcpsynflood Select OK How Icmp sweep attacks work What is an Icmp sweep?Icmp sweep attacks FortiGate IPS response to Icmp sweep attacksPredefined Icmp signatures Icmp sweep anomalies Configuring Icmp sweep protection Index FortiGate Version 3.0 MR7 IPS User GuideTechnical support