    def generate_config_section(self, config_dir_path, server_name, **kwargs):
        return """\
        ## Federation ##

        # Restrict federation to the following whitelist of domains.
        # N.B. we recommend also firewalling your federation listener to limit
        # inbound federation traffic as early as possible, rather than relying
        # purely on this application-layer restriction.  If not specified, the
        # default is to whitelist everything.
        #
        #federation_domain_whitelist:
        #  - lon.example.com
        #  - nyc.example.com
        #  - syd.example.com

        # Prevent federation requests from being sent to the following
        # blacklist IP address CIDR ranges. If this option is not specified, or
        # specified with an empty list, no ip range blacklist will be enforced.
        #
        # As of Synapse v1.4.0 this option also affects any outbound requests to identity
        # servers provided by user input.
        #
        # (0.0.0.0 and :: are always blacklisted, whether or not they are explicitly
        # listed here, since they correspond to unroutable addresses.)
        #
        federation_ip_range_blacklist:
          - '127.0.0.0/8'
          - '10.0.0.0/8'
          - '172.16.0.0/12'
          - '192.168.0.0/16'
          - '100.64.0.0/10'
          - '169.254.0.0/16'
          - '::1/128'
          - 'fe80::/64'
          - 'fc00::/7'

        # Report prometheus metrics on the age of PDUs being sent to and received from
        # the following domains. This can be used to give an idea of "delay" on inbound
        # and outbound federation, though be aware that any delay can be due to problems
        # at either end or with the intermediate network.
        #
        # By default, no domains are monitored in this way.
        #
        #federation_metrics_domains:
        #  - matrix.org
        #  - example.com
        """
A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks.