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The Arista MLS layer 2 switch must have all trunk links enabled statically.

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-255979ARST-L2-000160SV-255979r882279_ruleCCI-000366medium
Description
When trunk negotiation is enabled via Dynamic Trunk Protocol (DTP), considerable time can be spent negotiating trunk settings (802.1q or ISL) when a node or interface is restored. While this negotiation is happening, traffic is dropped because the link is up from a layer 2 perspective. Packet loss can be eliminated by setting the interface statically to trunk mode, thereby avoiding dynamic trunk protocol negotiation and significantly reducing any outage when restoring a failed link or switch.
STIGDate
Arista MLS EOS 4.X L2S Security Technical Implementation Guide2025-05-19

Related Frameworks

1 mapping across 5 frameworks
SCF0 mappings

No source states a mapping between these directly.

Also reachable in 3 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.

CFG-01Configuration Management Program
1.00
END-01Endpoint Device Management (EDM)
1.00
END-04Malicious Code Protection (Anti-Malware)
1.00
END-06Endpoint File Integrity Monitoring (FIM)
1.00
MON-01Continuous Monitoring
1.00
MON-01.7File Integrity Monitoring (FIM)
1.00
CFG-02Secure Baseline Configurations
0.50
CFG-02.7Approved Configuration Deviations
0.50
NIST 800-530 mappings

No source states a mapping between these directly.

Also reachable in 2 hops (100) 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.

AC-12Session Termination
1.00
AC-16(1)Dynamic Attribute Association
1.00
AC-17(1)Monitoring and Control
1.00
AC-2Account Management
1.00
AC-2(1)Automated System Account Management
1.00
AC-2(11)Usage Conditions
1.00
AC-2(3)Disable Accounts
1.00
AC-2(4)Automated Audit Actions
1.00
AC-24(1)Transmit Access Authorization Information
1.00
AC-25Reference Monitor
1.00

+90 more (top 10 by confidence shown)

NIST 800-1710 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.

3.4.1
1.00
3.4.2
1.00
CCI1 mapping
NIST CSF 2.00 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (5) 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.

PR.PSPlatform Security
0.50

Who does this work

10 NICE work roles and 9 EC-Council certifications.

This is an inference across published mappings, not a single claim by anyone. This check maps to a control, which maps to a Cybersecurity Framework outcome, which NIST assigns to the work roles below. EC-Council separately maps its certifications to those same roles.

A certification prepares someone for a role. It is not evidence that a holder is qualified, and neither NIST nor EC-Council has stated that any certification here addresses this check.

Work-role assignments published by NIST (NICE Framework Components 2.2.0 and the CSF 2.0 OLIR crosswalk). Certification mappings published by EC-Council.

Details

Check Text (C-255979r882279_chk)

Review the Arista MLS switch configuration to verify that all Ethernet interfaces designated as trunk links are statically configured to specify only member tagged VLAN traffic is allowed and all nonmember VLAN traffic will be dropped unless untagged traffic is associated with the interface's native VLAN. switch#show run | section trunk ! interface Ethernet6 description STIG Static Trunk speed forced 10000full switchport trunk native vlan 2102 switchport trunk allowed vlan 2100-2102 switchport mode trunk ! If trunk negotiation is enabled on any interface, this is a finding.

Fix Text (F-59598r882278_fix)

Configure static Ethernet interfaces for switchport trunk mode. Ensure required VLAN member tagged traffic is allowed and all other VLAN traffic will be dropped unless an associated untagged native VLAN for the Ethernet interface is allowed. switch#configure switch(config)#interface Ethernet6 description STIG Static Trunk speed forced 10000full switchport trunk native vlan 2102 switchport trunk allowed vlan 2100-2102 switchport mode trunk ! switch(config)#interface Ethernet7 description STIG Static Trunk speed forced 10000full switchport trunk native vlan 3102 switchport trunk allowed vlan 3100-3102 switchport mode trunk !