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Net Optics none manual Understand filter interactions, Cam

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Director

Understand filter interactions

It is important to understand that Director uses Content Addressable Memory (CAM) technology to implement filters. As each filter is defined, it is stored in the next available entry in the CAM. Each packet header is compared in the CAM, and the CAM returns the index of the first filter that the packet header matched. That filter, and only that filter, controls which monitoring ports receive a copy of the packet. Other filters are not executed for that packet. Therefore, filters are not completely independent; one filter can affect the operation of another.

Let's walk through an example of a filter interaction that may be unexpected. First, we will set up a filter for an IP address:

filter add in_ports=n1.5 ip_src=192.186.10.0 action=redir redir_ports=m.1 filter commit

Source IP =

Network Port 5 192.168.10.0 – Monitor Port 1

192.168.10.15

CAM

Address Filter

1n1.5 ip_src=192.186.10.0 m.1

lter add in_ports=n1.5 ip_src=192.168.10.0 ip_src_mask= 240 action=redir redir_

Figure 34: A simple IP address filter, shown with CAM

All traffic from Network Port 5 that comes from IP address 192.186.10.0 matches the first CAM entry and therefore is copied to Monitor Port 1.

Next, suppose we want another monitoring tool to see all the TCP traffic from Network Port 5, so we set up this filter:

filter add in_ports=n1.5 ip_proto=6 action=redir redir_ports=m.2 filter commit

Network Port 5

Source IP =				Monitor Port 1
192.186.10.0				Monitor Port 1
192.186.10.0
				Filter interactions
Protocol =				are not shown!
Protocol =				Monitor Port 2
TCP				Monitor Port 2
TCP

CAM

Address Filter

1n1.5 ip_src=192.186.10.0 m.1

2n1.5 ip_proto=TCP m.1

lter add in_ports=n1.5 ip_src=192.186.10.0 action=redir redir_ports=m.1 lter add in_ports=n1.5 ip_proto=6 action=redir redir_ports=m.2

Figure 35: Incorrect flow diagram of two filters; filter interaction in CAM is neglected

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Net Optics none manual Understand filter interactions, Cam

Contents

Smart Filtering Appliance Trademarks and Copyrights Contents Appendix B Appendix aAppendix C Filter parametersChapter Introduction Ease of Use Key FeaturesMonitor port Filtering Passive, Secure TechnologyDescription About this GuideDirector internal architecture Director ArchitectureDirector Management USB portNetwork Links Typical ApplicationMonitoring Tools In-line Monitoring of 10 Gigabit Links IBypass Switch MethodExternal Network Tap method Director Front Panel Power LEDsMonitor Port LEDs DNM / Network Port LEDsXFP Director Rear PanelChapter Installing Director Unpack and Inspect the Director device Plan the InstallationInstall SFP and XFP Monitor port Modules Install Director Network ModulesRack Mount the Director device Connect the local CLI Interface Connect Power to DirectorBaud Data bits No parity 1 stop bit No flow control Connect the remote CLI InterfaceTip To connect the CLI for remote use over the Management portTo log into the CLI Log into the CLIChange Director User Name and Password Configure Director using the CLITo change the user name and password Assign a New Manager IP Address To change the port modeTo assign a new Manager IP address to Director Change Port ModesSet the Current Date and Time Save and Load Director ConfigurationsTo view CLI help information Using the CLI Help CommandCurrent config file Using the CLI Command History BufferTo connect a Span port Connect Span Ports to DirectorTo connect an in-line network link Connect Director With In-line Network LinksCheck the Installation Configure a Matrix Switch connection in DirectorConnect Monitoring Tools to Director Syntax Chapter Configuring Filters Using the CLICopy Traffic From Any Network Port to Any Monitor Port Enter filter commit. The switch connection is activatedLter add inports=n1.1 action=redir redirports=m.3-m.5 Regenerate Traffic to Any Set of Monitor PortsTo create a filter that selects IPv4 packets by protocol Create FiltersLogical and filter connection Create Complex FiltersUDP View filtersConfigurable 10 Gigabit XFP ports used as Network ports Work with configurable 10 Gigabit portsNetwork Port 11 XFP Port CAM Understand filter interactionsFlow diagram now looks as follows N1.1 ipproto=UDP action=drop N1.1 m.1 Exclusive filtersUnderstand pending and active filters To change the Director filter configurationEnter filter list to view the pending filter list Filter capacity User interactionsDaisy-chaining Multiple Director Chassis Specifications, chassis Appendix a Director SpecificationsEnvironmental Specifications, DNMCertifications Available ModelsCommand Sub-Command Parameters Example and description Appendix B Command Line InterfaceFilter add and filter ins commands Command may includeFilter add ipv6=n inports=n1.1-n1.3 ip Src=10.1.1.1 action=dropFilter list Load myconfiguration-1Filter running Filter syncShow myconfiguration-1 Save myconfiguration-1Passwd PingSysip ipaddr=192.168.1.2 netmask=255.255.0.0 Sysip commitSysip show TimeUser show This This command is only available at root level CommandUser add name=bob pw=bob-pw priv=3 Is onlyDirector Filter Parameters Qual Value Example Description Filter parametersNum Keyword Protocol Appendix C Protocol NumbersMobile L2TP Limitations on Warranty and Liability By Net Optics, Inc. All Rights Reserved