Verify each router enforces approved authorizations for controlling the flow of information between interconnected networks in accordance with applicable policy. Junos enforces information flow via stateless firewall filters and unicast Reverse Path Forwarding (uRPF). uRPF performs a forwarding table lookup to validate the incoming packet's source address is appropriate for the arriving interface. Verify uRPF is enabled on applicable interfaces. The example shows uRPF and the stateless firewall filter applied. Verify the interface and assigned addresses are appropriate for the target environment. [edit interfaces] <interface name> { unit <logical unit number> { family inet { rpf-check; filter { input deny-prod-to-mgt; } } family inet6 { rpf-check; filter { input deny-prod-to-mgt-v6; } } } } Note: Some Juniper devices support both monolithic filters and filter lists. Filter lists separate each term, or set of terms, into a separate filter that is applied sequentially to an interface. If using filter lists, the keywords "input" or "output" change to "input-list" or "output-list". Verify the final list item is a deny-all filter. [edit firewall] family inet { filter deny-prod-to-mgt { term 1 { from { source-address { <production IPv4 subnet/mask>; } destination-address { <MGT IPv4 subnet/mask>; } } then { log; syslog; discard; } } term 2 { from { source-address { <production IPv4 subnet/mask>; } } then accept; } } } family inet6 { filter deny-prod-to-mgt-v6 { term 1 { from { source-address { <production IPv6 subnet/prefix>; } destination-address { <MGT IPv6 subnet/prefix>; } } then { log; syslog; discard; } } term 2 { from { source-address { <production IPv6 subnet/prefix>; } } then accept; } } } If the router does not enforce approved authorizations for controlling the flow of information between interconnected networks in accordance with applicable policy, this is a finding.