Cisco Systems Add/Edit Internal Group Policy > Client Firewall

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Cisco ASA 5500 Series Configuration Guide using ASDM
Chapter69 General VPN Setup
ACL Manager
– Permit—Permits all matching traffic.
– Deny—Denies all matching traffic.
•Host/Network IP Address—Identifies the networks by IP address.
– IP address—The IP address of the host or network.
– Mask—The subnet mask of the host or network
•Description—(Optional) Enter a description of the access rule.
Modes
The following table shows the modes in which this feature is available:
Add/Edit Internal Group Policy > Client Firewall
The Add or Edit Group Policy Client Firewall dialog box lets you configure firewall settings for VPN
clients for the group policy being added or modified.
Note Only VPN clients running Microsoft Windows can use these firewall features. They are currently not
available to hardware clients or other (non-Windows) software clients.
A firewall isolates and protects a computer from the Internet by inspecting each inbound and outbound
individual packet of data to determine whether to allow or drop it. Firewalls provide extra security if
remote users in a group have split tunneling configured. In this case, the firewall protects the user’s PC,
and thereby the corporate network, from intrusions by way of the Internet or the user’s local LAN.
Remote users connecting to the ASA with the VPN client can choose the appropriate firewall option.
In the first scenario, a remote user has a personal firewall installed on the PC. The VPN client enforces
firewall policy defined on the local firewall, and it monitors that firewall to make sure it is running. If
the firewall stops running, the VPN client drops the connection to the ASA. (This firewall enforcement
mechanism is called Are You There (AYT), because the VPN client monitors the firewall by sending it
periodic “are you there?” messages; if no reply comes, the VPN client knows the firewall is down and
terminates its connection to the ASA.) The network administrator might configure these PC firewalls
originally, but with this approach, each user can customize his or her own configuration.
In the second scenario, you might prefer to enforce a centralized firewall policy for personal firewalls
on VPN client PCs. A common example would be to block Internet traffic to remote PCs in a group using
split tunneling. This approach protects the PCs, and therefore the central site, from intrusions from the
Internet while tunnels are established. This firewall scenario is called push policy or Central Protection
Policy (CPP). On the ASA, you create a set of traffic management rules to enforce on the VPN client,
associate those rules with a filter, and designate that filter as the firewall policy. The ASA pushes this
policy down to the VPN client. The VPN client then in turn passes the policy to the local firewall, which
enforces it.
Firewall Mode Security Context
Routed Transparent Single
Multiple
Context System
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