ARST-RT-000440 - The Arista router must be configured to only permit management traffic that ingresses and egresses the out-of-band management (OOBM) interface.

Information

The OOBM access router will connect to the management interface of the managed network elements. The management interface can be a true OOBM interface or a standard interface functioning as the management interface. In either case, the management interface of the managed network element will be directly connected to the OOBM network.

An OOBM interface does not forward transit traffic, thereby providing complete separation of production and management traffic. Since all management traffic is immediately forwarded into the management network, it is not exposed to possible tampering. The separation also ensures that congestion or failures in the managed network do not affect the management of the device. If the device does not have an OOBM port, the interface functioning as the management interface must be configured so that management traffic does not leak into the managed network and that production traffic does not leak into the management network.

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

Solution

If the Arista management interface is a routed interface, it must be configured with both an ingress and egress ACL.

Step 1: Configure the ingress filter to only allow management, IGP, and ICMP traffic.

LEAF-1A(config)#ip access-list FILTER_INBOUND
LEAF-1A(config-acl-FILTER_INBOUND)#permit ospf any any
LEAF-1A(config-acl-FILTER_INBOUND)#permit icmp any any echo
LEAF-1A(config-acl-FILTER_INBOUND)#permit icmp any any echo-reply
LEAF-1A(config-acl-FILTER_INBOUND)#permit ip 10.10.10.0/24 any
LEAF-1A(config-acl-FILTER_INBOUND)#deny ip any any log

Step 2: Configure the outbound filter to only allow management, IGP, and ICMP traffic.

LEAF-1A(config)#ip access-list FILTER_OUTBOUND
LEAF-1A(config-acl-FILTER_OUTBOUND)#permit ospf any any
LEAF-1A(config-acl-FILTER_OUTBOUND)#permit icmp any any echo
LEAF-1A(config-acl-FILTER_OUTBOUND)#permit icmp any any echo-reply
LEAF-1A(config-acl-FILTER_OUTBOUND)#permit ip any 10.10.10.0/24
LEAF-1A(config-acl-FILTER_OUTBOUND)#deny ip any any log

Step 3: Set the managed interface to have an inbound and outbound ACL configured.

LEAF-1A(config)#interface ethernet 3
LEAF-1A(config-if-Et3)# ip access-group FILTER_INBOUND in
LEAF-1A(config-if-Et3)# ip access-group FILTER_OUTBOUND out

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Arista_MLS_EOS_4-2x_Y24M07_STIG.zip

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7a., CAT|II, CCI|CCI-001097, CCI|CCI-004931, Rule-ID|SV-256025r991788_rule, STIG-ID|ARST-RT-000440, Vuln-ID|V-256025

Plugin: Arista

Control ID: 07a3c175013b8a2f49d43ddb57e69427a556757b19fda98b634fa4beeac39e5c