
Nortel Switched Firewall 2.3.3 User’s Guide and Command Reference
190
Layer 2 and Layer 3 Firewalls
213455-L, October 2005
Overview
A bridge connects two separate network segments in a protocol-independent way. You
implement a bridging firewall if you want to change your configuration without having to
reconfigure your entire network topology. A bridging firewall is also called transparent or
stealth firewall because it is effectively invisible on the network.
All protocols traverse transparently through a bridge, because forwarding is done at Layer 2.
Packets are forwarded based on the Ethernet address, rather than the IP address. An Ethernet
bridge distributes Ethernet frames from one port to the other ports associated with the bridge
interface.
N
OTE
–
Layer 2 and Layer 3 firewalls are not supported on the NSF 5109 model.
NSF 2.3.3 supports two modes: Layer 2 and Layer 3 firewall. The procedures to configure
Layer 2 or Layer 3 firewall differ only in the configuration of the bridge interface IP addresses.
Layer 3 firewall requires valid IP addresses for
addr1
and
addr2
commands in the
/cfg/net/bridge
<bridge#>
menu, and Layer 2 bridging firewalls require no IP
addresses.
Содержание 5100 Series Release 2.3.3
Страница 18: ...Nortel Switched Firewall 2 3 3 User s Guide and Command Reference 18 Preface 213455 L October 2005...
Страница 20: ...Nortel Switched Firewall 2 3 3 User s Guide and Command Reference 20 Getting started 213455 L October 2005...
Страница 28: ...Nortel Switched Firewall 2 3 3 User s Guide and Command Reference 28 Introduction 213455 L October 2005...
Страница 90: ...Nortel Switched Firewall 2 3 3 User s Guide and Command Reference 90 Initial setup 213455 L October 2005...
Страница 188: ...Nortel Switched Firewall 2 3 3 User s Guide and Command Reference 188 Redundant Firewalls 213455 L October 2005...
Страница 228: ...Nortel Switched Firewall 2 3 3 User s Guide and Command Reference 228 Applications 213455 L October 2005...
Страница 248: ...Nortel Switched Firewall 2 3 3 User s Guide and Command Reference 248 Basic system management 213455 L October 2005...
Страница 250: ...Nortel Switched Firewall 2 3 3 User s Guide and Command Reference 250 Command reference 213455 L October 2005...
Страница 264: ...Nortel Switched Firewall 2 3 3 User s Guide and Command Reference 264 The Command Line Interface 213455 L October 2005...
Страница 374: ...Nortel Switched Firewall 2 3 3 User s Guide and Command Reference 374 Command reference 213455 L October 2005...
Страница 376: ...Nortel Switched Firewall 2 3 3 User s Guide and Command Reference 376 Appendices 213455 L October 2005...
Страница 406: ...Nortel Switched Firewall 2 3 3 User s Guide and Command Reference 406 Common tasks 213455 L October 2005...