V-217019

Discussion

The Routing Engine handles traffic destined to the router—the key component used to build forwarding paths and is instrumental with all network management functions. Hence, any disruption or DoS attack to the Routing Engine can result in mission critical network outages.

Check Content

Review the filter for the router’s receive path and verify that it will only allow specific management plane traffic from specific sources.

Verify filter has been configured as shown in the example below.

firewall {
    family inet {
         …
        …
        …
        }
        filter DESTINED_TO_RE {
            term ALLOW_OSPF {
                from {
                    protocol ospf;
                }
                then accept;
            }
            term ALLOW_BGP {
                from {
                    source-address {
                        11.1.12.1/32;
                        11.1.23.3/32;
                        11.1.25.5/32;
                    }
                    protocol tcp;
                    port bgp;
                }
            }
            term FILTER_TCP {
                from {
                    destination-address {
                        11.1.12.0/24;
                    }
                    protocol tcp;
                    destination-port [ ssh tacacs telnet ];
                }
                then accept;
            }
            term FILTER_UDP {
                from {
                    destination-address {
                        11.1.12.0/24;
                    }
                    protocol udp;
                    destination-port [ntp snmp ];
                }
                then accept;
            }
            term ICMP_ANY {
                from {
                    protocol icmp;
                }
                then accept;
            }
            term DENY_BY_DEFAULT {
                then {
                    log;
                    discard;
                }
            }
        }
    }

Verify that the input filter has been applied to loopback interface as shown in the example below.
    
interfaces {
…
…
…
    lo0 {
        unit 0 {
            family inet {
                filter {
                    input-list [ DESTINED_TO_RE CoPP_Policy ];
                }
                address 2.2.2.2/32;
            }
         }
    }
}

If the router is not configured with a receive-path filter to restrict traffic destined to itself, this is a finding