The Juniper EX switch must be configured to verify two-way connectivity on all interswitch trunked interfaces.

Description

<VulnDiscussion>In topologies where fiber optic interconnections are used, physical misconnections can occur that allow a link to appear to be up when there is a mismatched set of transmit/receive pairs. When such a physical misconfiguration occurs, protocols such as STP can cause network instability. OAM LFM and LAG are industry standard layer 2 protocols that can detect these physical misconfigurations by verifying that traffic is flowing bidirectionally between neighbors. Interfaces with OAM configured, and LAG interfaces, periodically transmit packets to neighbor devices. If the packets are not exchanged within a specific time frame, the link is flagged as unidirectional and the interface is shut down. OAM LFM and LAG require both connected devices to be configured.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>