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JUEX-RT-000450 - The Juniper PE router must be configured with Unicast Reverse Path Forwarding (uRPF) loose mode, or a firewall filter, enabled on all CE-facing interfaces.

Information

The uRPF feature, and ingress firewall filters, are defenses against spoofing and denial-of-service (DoS) attacks by verifying if the source address of any ingress packet is reachable. To mitigate attacks that rely on forged source addresses, all provider edge routers must enable uRPF or ingress firewall filters to guarantee that all packets received from a CE router contain source addresses that are in the route table.

NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.

Solution

Enable uRPF loose mode or apply an ingress filter on all CE-facing interfaces.

For example, configure uRPF on CE-facing interfaces:
set interfaces ge-0/0/0 unit 0 family inet rpf-check mode loose
set interfaces ge-0/0/0 unit 0 family inet6 rpf-check mode loose

For example, configure firewall filter and apply to CE-facing interfaces (only for devices that do not support uRPF):
set policy-options prefix-list cust1-prefixes-ipv4 192.0.2.0/24
set policy-options prefix-list cust1-prefixes-ipv6 2001:db8:2::/64

set firewall family inet filter cust1-prefixes-ipv4 term 1 from source-prefix-list cust1-prefixes-ipv4
set firewall family inet filter cust1-prefixes-ipv4 term 1 then accept
set firewall family inet filter cust1-prefixes-ipv4 term default then log
set firewall family inet filter cust1-prefixes-ipv4 term default then syslog
set firewall family inet filter cust1-prefixes-ipv4 term default then discard
set firewall family inet6 filter cust1-prefixes-ipv6 term 1 from source-prefix-list cust1-prefixes-ipv6
set firewall family inet6 filter cust1-prefixes-ipv6 term 1 then accept
set firewall family inet6 filter cust1-prefixes-ipv6 term default then log
set firewall family inet6 filter cust1-prefixes-ipv6 term default then syslog
set firewall family inet6 filter cust1-prefixes-ipv6 term default then discard

set interfaces ge-0/0/0 unit 0 family inet filter input cust1-prefixes-ipv4
set interfaces ge-0/0/0 unit 0 family inet6 filter input cust1-prefixes-ipv6

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Juniper_EX_Switches_Y24M01_STIG.zip

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7a., CAT|II, CCI|CCI-001097, Rule-ID|SV-254017r844084_rule, STIG-ID|JUEX-RT-000450, Vuln-ID|V-254017

Plugin: Juniper

Control ID: 5d7619e83be0eff12f15451b309c0bb2540b9af51fa76d781dad0f7eefd9e9dd