STIGViewer Support

The Juniper perimeter router must be configured to have Proxy ARP disabled on all external interfaces.

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-217042JUNI-RT-000370SV-217042r855897_ruleCCI-002403medium
Description
When Proxy ARP is enabled on a router, it allows that router to extend the network (at Layer 2) across multiple interfaces (LAN segments). Because proxy ARP allows hosts from different LAN segments to look like they are on the same segment, proxy ARP is only safe when used between trusted LAN segments. Attackers can leverage the trusting nature of proxy ARP by spoofing a trusted host and then intercepting packets. Proxy ARP should always be disabled on router interfaces that do not require it, unless the router is being used as a LAN bridge.
STIGDate
Juniper Router RTR Security Technical Implementation Guide2024-12-05

Related Frameworks

1 mapping across 3 frameworks
SCF0 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (2) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

NET-03Boundary Protection
0.50
NET-04.1Deny Traffic by Default & Allow Traffic by Exception
0.50
NIST 800-530 mappings

No source states a mapping between these directly.

Also reachable in 2 hops (8) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

CM-6Configuration Settings
1.00
SC-24Fail in Known State
1.00
SC-47Alternate Communications Paths
1.00
SC-5Denial-of-service Protection
1.00
SC-7Boundary Protection
1.00
SC-7(11)Restrict Incoming Communications Traffic
1.00
SC-7(29)Separate Subnets to Isolate Functions
1.00
SC-7(5)Deny by Default — Allow by Exception
1.00
CCI1 mapping

Details

Check Text (C-217042r855897_chk)

Review the router configuration to determine if IP Proxy ARP is disabled on all external interfaces. interfaces { description "NIPRNet"; ge-0/0/0 { unit 0 { proxy-arp restricted; family inet { If IP Proxy ARP is enabled on any external interface, this is a finding.

Fix Text (F-18269r296995_fix)

This requirement is not applicable for the DoDIN Backbone. Disable Proxy ARP on all external interfaces as shown in the example below. [edit interfaces em0 unit 0] delete proxy-arp restricted