STIGQter: STIG Summary: Arista MLS EOS 4.X Router Security Technical Implementation Guide Version: 2 Release: 2 Benchmark Date: 02 Apr 2025:

The Arista router must be configured to produce audit records containing information to establish where the events occurred.

DISA Rule

SV-256008r882366_rule

Vulnerability Number

V-256008

Group Title

SRG-NET-000076-RTR-000001

Rule Version

ARST-RT-000230

Severity

CAT II

CCI(s)

• CCI-000132 - Ensure that audit records containing information that establishes where the event occurred.
• CCI-000133 - Ensure that audit records containing information that establishes the source of the event.
• CCI-000134 - Ensure that audit records containing information that establishes the outcome of the event.

Weight

10

Fix Recommendation

Configure the router to record the interface in the log record for packets being dropped.

Step 1: Configure the ACL.

router(config)#ip access-list test1
router(config-acl-test1)#15 permit ip 10.30.30.0/24 host 10.20.10.1
router(config-acl-test1)#15 deny ip 10.30.10.0/24 host 10.20.10.1 log

Step 2: Apply the ACL ingress on the appropriate interface.

router(config)#interface ethernet 3
router(config-if-Et3)#ip access-group test1 in

Check Contents

The Arista router must log all packets that have been dropped via the access control list (ACL).

Log output must contain an interface name as to where the packet was filtered.

Step 1: To verify the deny ACL is created with the log statement for dropped packets, execute the command "show ip access-list".

ip access-list test1
permit ip 10.30.30.0/24 host 10.20.10.1
deny ip 10.30.10.0/24 host 10.20.10.1 log

Step 2: To verify the ACL ingress is applied on the appropriate interface, execute the command "show run interface YY".

interface ethernet 3
ip access-group test1 in

######

Variables in the syslog messages display the following values:
---------------------------------------------------------------
acl Name of ACL.
intf Name of interface that received the packet.
filter Action triggered by ACL (denied or permitted).
protocol IP protocol specified by packet.
vlan Number of VLAN receiving packet.
ether EtherType protocol specified by packet.
src-ip and dst-ip source and destination IP addresses.
src-prt and dst-prt source and destination ports.
src-mac and dst-mac source and destination MAC addresses.

If the logged output does not contain an interface name as to where the packet was filtered, this is a finding.

If the Arista router fails to log all packets that have been dropped via the ACL, this is a finding.

Vulnerability Number

V-256008

Documentable

False

Rule Version

ARST-RT-000230

Severity Override Guidance

The Arista router must log all packets that have been dropped via the access control list (ACL).

Log output must contain an interface name as to where the packet was filtered.

Step 1: To verify the deny ACL is created with the log statement for dropped packets, execute the command "show ip access-list".

ip access-list test1
permit ip 10.30.30.0/24 host 10.20.10.1
deny ip 10.30.10.0/24 host 10.20.10.1 log

Step 2: To verify the ACL ingress is applied on the appropriate interface, execute the command "show run interface YY".

interface ethernet 3
ip access-group test1 in

######

Variables in the syslog messages display the following values:
---------------------------------------------------------------
acl Name of ACL.
intf Name of interface that received the packet.
filter Action triggered by ACL (denied or permitted).
protocol IP protocol specified by packet.
vlan Number of VLAN receiving packet.
ether EtherType protocol specified by packet.
src-ip and dst-ip source and destination IP addresses.
src-prt and dst-prt source and destination ports.
src-mac and dst-mac source and destination MAC addresses.

If the logged output does not contain an interface name as to where the packet was filtered, this is a finding.

If the Arista router fails to log all packets that have been dropped via the ACL, this is a finding.

Check Content Reference

M

Target Key

5513