V-283833

Discussion

Unrestricted traffic may contain malicious traffic that poses a threat to an enclave or other connected networks. Unrestricted traffic may also transit a network, which uses bandwidth and other resources. Traffic can be restricted directly by an access control list (ACL), which is a firewall function, or by Policy Routing. Policy Routing is a technique used to make routing decisions based on several criteria other than the destination network, including source or destination network, source or destination address, source or destination port, protocol, packet size, and packet classification. This overrides the router's normal routing procedures used to control the specific paths of network traffic. It is normally used for traffic engineering but can also be used to meet security requirements; for example, traffic that is not allowed can be routed to the Null0 or discard interface. Policy Routing can also be used to control which prefixes appear in the routing table. This requirement is intended to allow network administrators the flexibility to use whatever technique is most effective.

Check Content

This requirement is not applicable for the DODIN Backbone.

Review the router configuration to determine if the router allows only incoming communications from authorized sources to be routed to authorized destinations.

Use the command below and verify "Ingress Filter" or "Egress Filter", if needed, are applied: 

- show filter ip 10

Entry               : 10
Description         : (Not Specified)
Log Id              : n/a
Src. IP             : 172.200.200.2/32
Src. Port           : n/a
Dest. IP            : 172.150.150.2/32
Dest. Port          : n/a

- show filter ipv6 20

Filter Match Criteria : IPv6
-------------------------------------------------------------------------------
Entry               : 10
Description         : (Not Specified)
Log Id              : n/a
Src. IP             : 2001:acad:1234:200::2/128
Src. Port           : n/a
Dest. IP            : 2001:acad:1234:150::2/128
Dest. Port          : n/a

If the router does not restrict incoming communications to allow only authorized sources and destinations, this is a finding.