Enterasys csx200 Guia Do Utilizador

CSX200 Family User’s Guide

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Filtering is used to allow efficient usage of network resources and provide security for your 
network and hosts. 

The CSX200 supports IP Internet Firewall filtering to prevent 

unauthorized access to your system and network resources from the Internet or a corporate 
Intranet. Security can be configured to permit or deny IP traffic. The security is established by 
configuring IP access filters, which are based on source IP address, source mask, destination IP 
address, destination mask, protocol type, and application port identifiers for both Transmission 
Control Protocol (TCP) and User Datagram Protocol (UDP) protocols. These IP access filters 
allow individual IP source and destination pair filtering as well as IP address ranges and wild 
carding to match any IP address. These Firewall filters can be defined to allow inbound only, 
outbound only, or bi-directional IP communication up to the UDP and TCP application port level. 
Firewall access filters provide a lot of flexibility to establish a powerful IP security barrier. The 
CSX200 supports the IP Access Control (from the ctip-mib) Internet Firewall Filter.

Bridge filtering allows a network administrator to control the flow of packets 

across the CSX200. Bridge filtering can be used to “deny” or “allow” packets based on a “matched 
pattern” using a specified position and hexadecimal content within the packet. This enables 
restricting or forwarding of messages based on address, protocol, or data content. Common uses 
include preventing access to remote networks, controlling unauthorized access to the local 
network, and limiting unnecessary traffic. 

The CSX200 supports the following Bridge Filters:

dot1dStatic Filters (IETF RFC1493)

Ethernet Special Filtering Database (from the ctbridge-mib)