Router(config-line)# password Dots-4-georg3
Provide a basic protection for the line passwords by using the following global
configuration command.
Router(config)# service password-encryption
TCP/IP Filters
Carefully consider which TCP/IP services will be allowed through and to the perimeter routers
and firewalls (inbound and outbound). Use the following guidelines for creating filters: those
services that are not explicitly permitted are prohibited. The following tables present common
services to restrict because they can be used to gather information about the protected
network or they have weaknesses that can be exploited against the protected network.
. Table 1 lists those TCP or UDP servers that should be completely blocked at the
perimeter router or firewall. These services should not be allowed across the router or
the firewall in either direction. Also, they should not be allowed to the router or the
firewall.
. Table 2 lists those TCP or UDP servers on the protected network, on the router or on the
firewall that should not be accessible by external clients.
. Table 3 lists the common TCP or UDP servers on the protected network, on the router or
on the firewall that may need some access by internal or external clients and servers.
Many of these services can be filtered to the few authorized computers (e.g., ftp server,
mail server, domain name server, web server) on the protected network or on the DMZ
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