The Cisco perimeter switch must be configured to have Proxy ARP disabled on all external interfaces.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-220451 | CISC-RT-000380 | SV-220451r856242_rule | CCI-002403 | medium |
| Description | ||||
| When Proxy ARP is enabled on a switch, it allows that switch 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 switch interfaces that do not require it unless the switch is being used as a LAN bridge. | ||||
| STIG | Date | |||
| Cisco IOS Switch RTR Security Technical Implementation Guide | 2026-03-04 | |||
Related Frameworks
1 mapping across 3 frameworks
Related 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.
- DISA STIG Benchmark (XCCDF)V3R3intersects(normalised)
- DISA CCI List2025-01-23equal to(normalised)
- SCF Secure Traceability Relationship Mapping (STRM)2026.2intersects
- DISA STIG Benchmark (XCCDF)V3R3intersects(normalised)
- DISA CCI List2025-01-23equal to(normalised)
- SCF Secure Traceability Relationship Mapping (STRM)2026.2intersects
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.
- DISA STIG Benchmark (XCCDF)V3R3intersects(normalised)
- DISA STIG Benchmark (XCCDF)3our copyintersects(normalised)
- DISA STIG Benchmark (XCCDF)3intersects(normalised)
- DISA CCI List2025-01-23equal to(normalised)
- DISA STIG Benchmark (XCCDF)V3R3intersects(normalised)
- DISA STIG Benchmark (XCCDF)V1R2our copyintersects(normalised)
- DISA STIG Benchmark (XCCDF)V1R2intersects(normalised)
- DISA CCI List2025-01-23equal to(normalised)
- DISA STIG Benchmark (XCCDF)V3R3intersects(normalised)
- DISA STIG Benchmark (XCCDF)V2R1our copyintersects(normalised)
- DISA STIG Benchmark (XCCDF)V2R1intersects(normalised)
- DISA CCI List2025-01-23equal to(normalised)
- DISA STIG Benchmark (XCCDF)V3R3intersects(normalised)
- DISA STIG Benchmark (XCCDF)V2R1our copyintersects(normalised)
- DISA STIG Benchmark (XCCDF)V2R1intersects(normalised)
- DISA CCI List2025-01-23equal to(normalised)
- DISA STIG Benchmark (XCCDF)V3R3intersects(normalised)
- DISA STIG Benchmark (XCCDF)V1R2our copyintersects(normalised)
- DISA STIG Benchmark (XCCDF)V1R2intersects(normalised)
- DISA CCI List2025-01-23equal to(normalised)
- DISA STIG Benchmark (XCCDF)V3R3intersects(normalised)
- DISA CCI List2025-01-23equal to(normalised)
- DISA STIG Benchmark (XCCDF)V3R3intersects(normalised)
- DISA STIG Benchmark (XCCDF)V3R4our copyintersects(normalised)
- DISA STIG Benchmark (XCCDF)V3R4intersects(normalised)
- DISA CCI List2025-01-23equal to(normalised)
- DISA STIG Benchmark (XCCDF)V3R3intersects(normalised)
- DISA STIG Benchmark (XCCDF)V1R2our copyintersects(normalised)
- DISA STIG Benchmark (XCCDF)V1R2intersects(normalised)
- DISA CCI List2025-01-23equal to(normalised)
CCI1 mapping
CCI-002403
1.00
- DISA STIG Benchmark (XCCDF)V3R3intersects(normalised)
Details
Check Text (C-220451r856242_chk)
Review the switch configuration to determine if IP Proxy ARP is disabled on all external interfaces as shown in the example below:
interface GigabitEthernet0/1
description link to DISN
ip address x.1.12.2 255.255.255.252
no ip proxy-arp
Note: By default, Proxy ARP is enabled on all interfaces; hence, if enabled, it will not be shown in the configuration.
If IP Proxy ARP is enabled on any external interface, this is a finding.
Fix Text (F-22155r508433_fix)
Disable Proxy ARP on all external interfaces as shown in the example below:
SW1(config)#int g0/1
SW1(config-if)#no ip proxy-arp