Chapter 5 Configuring Access Lists and Filtering GSS Traffic
Deploying GSS Devices Behind Firewalls
5-12
Cisco Global Site Selector Administration Guide
OL-10410-01
Deploying GSS Devices Behind Firewalls
This section describes how to configure your GSS for deployment behind a
firewall. It contains the following topics:
•
GSS Firewall Deployment Overview
•
Configuring GSS Devices Behind a Firewall
GSS Firewall Deployment Overview
In addition to the packet-filtering features of the
access-list
and
access-group
commands (see the
“Filtering GSS Traffic Using Access Lists”
section), you can
also deploy your GSS devices behind an existing firewall on your enterprise
network.
When you configure your GSS for deployment behind a firewall, you must allow
DNS traffic into the device. If you have multiple GSS devices deployed so that
traffic between the devices must pass through a firewall, configure the firewall to
allow inter-GSS communications and inter-GSS status reporting. Depending on
your GSS configuration, you can also allow other traffic to pass through the
firewall. This requirement depends on your GSS configuration (for example, if
you are using TCP-based or KAL-AP keepalives) and the ability to access certain
GSS services through the firewall (for example, SNMP).
The GSS does not support deployment of devices behind a NAT for inter-GSS
communication. The communication between the GSS devices cannot include an
intermediate device behind a NAT because the actual IP address of the devices is
embedded in the payload of the packets.
To configure your firewall to function with a GSS device, follow the guidelines
outlined in
Table 5-2
and
Table 5-3
to permit inbound and outbound traffic
transmitted to and received from the specified GSS ports. If you are using stateful
firewalls, the rules for return traffic outlined in
Table 5-2
and
Table 5-3
may not
be required.
In addition, use the
access-list
and
access-group
commands to enable authorized
GSS traffic to the specified ports. By default, the GSS interface blocks all ports
not explicitly permitted in your access list once you associate the access list with
an Ethernet interface.