Cisco 7609-S Configuration Guide - Page 116

Transparent Firewall Guidelines, Transparent Firewall Network with Two Bridge Groups

Page 116 highlights

Transparent Mode Overview Chapter 5 Configuring the Firewall Mode Figure 5-7 shows two networks connected to the FWSM, which has two bridge groups. Figure 5-7 Transparent Firewall Network with Two Bridge Groups 10.1.1.1 Management IP Bridge Group 1 10.1.1.2 10.1.1.3 10.2.1.1 Management IP Bridge Group 2 10.2.1.2 10.2.1.3 92902 Transparent Firewall Guidelines Follow these guidelines when planning your transparent firewall network: • A management IP address is required for each bridge group. Unlike routed mode, which requires an IP address for each interface, a transparent firewall has an IP address assigned to the entire bridge group. The FWSM uses this IP address as the source address for packets originating on the FWSM, such as system messages or AAA communications. In addition to the bridge group management address, you can optionally configure a management interface; see the "Management Interface" section on page 5-8 for more information. The management IP address must be on the same subnet as the connected network. The FWSM does not support traffic on secondary networks; only traffic on the same network as the management IP address is supported. See the "Assigning an IP Address to a Bridge Group" section on page 6-6 for more information about management IP subnets. • Each bridge group uses an inside interface and an outside interface only. • Each directly-connected network must be on the same subnet. • Do not specify the bridge group management IP address as the default gateway for connected devices; devices need to specify the router on the other side of the FWSM as the default gateway. • The default route for the transparent firewall, which is required to provide a return path for management traffic, is only applied to management traffic from one bridge group network. This is because the default route specifies an interface in the bridge group as well as the router IP address on the bridge group network, and you can only define one default route. If you have management traffic from more than one bridge group network, you need to specify a static route that identifies the network from which you expect management traffic. 5-10 Catalyst 6500 Series Switch and Cisco 7600 Series Router Firewall Services Module Configuration Guide using ASDM OL-20748-01

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5-10
Catalyst 6500 Series Switch and Cisco 7600 Series Router Firewall Services Module Configuration Guide using ASDM
OL-20748-01
Chapter 5
Configuring the Firewall Mode
Transparent Mode Overview
Figure 5-7
shows two networks connected to the FWSM, which has two bridge groups.
Figure 5-7
Transparent Firewall Network with Two Bridge Groups
Transparent Firewall Guidelines
Follow these guidelines when planning your transparent firewall network:
A management IP address is required for each bridge group.
Unlike routed mode, which requires an IP address for each interface, a transparent firewall has an
IP address assigned to the entire bridge group. The FWSM uses this IP address as the source address
for packets originating on the FWSM, such as system messages or AAA communications. In
addition to the bridge group management address, you can optionally configure a management
interface; see the
“Management Interface” section on page 5-8
for more information.
The management IP address must be on the same subnet as the connected network. The FWSM does
not support traffic on secondary networks; only traffic on the same network as the management IP
address is supported. See the
“Assigning an IP Address to a Bridge Group” section on page 6-6
for
more information about management IP subnets.
Each bridge group uses an inside interface and an outside interface only.
Each directly-connected network must be on the same subnet.
Do not specify the bridge group management IP address as the default gateway for connected
devices; devices need to specify the router on the other side of the FWSM as the default gateway.
The default route for the transparent firewall, which is required to provide a return path for
management traffic, is only applied to management traffic from one bridge group network. This is
because the default route specifies an interface in the bridge group as well as the router IP address
on the bridge group network, and you can only define one default route. If you have management
traffic from more than one bridge group network, you need to specify a static route that identifies
the network from which you expect management traffic.
10.2.1.1
10.1.1.1
Management IP
Bridge Group 2
10.2.1.2
Management IP
Bridge Group 1
10.1.1.2
10.2.1.3
10.1.1.3
92902