|The Juniper EX switch must be configured to disable non-essential capabilities.
|A compromised switch introduces risk to the entire network infrastructure as well as data resources that are accessible via the network. The perimeter defense has no oversight or control of...
|The Juniper EX switch must be configured to uniquely identify all network-connected endpoint devices before establishing any connection.
|Controlling LAN access via 802.1x authentication can assist in preventing a malicious user from connecting an unauthorized PC to an access interface to inject or receive data from the network...
|The Juniper EX switch must be configured to authenticate all network-connected endpoint devices before establishing any connection.
|Without authenticating devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity.
For distributed architectures (e.g., service-oriented architectures),...
|The Juniper EX switch must be configured to enable IP Source Guard on all user-facing or untrusted access VLANs.
|IP Source Guard provides source IP address filtering on an untrusted layer 2 interface to prevent a malicious host from impersonating a legitimate host by assuming the legitimate host's IP...
|The Juniper EX switch must be configured to enable Dynamic Address Resolution Protocol (ARP) Inspection (DAI) on all user VLANs.
|DAI intercepts Address Resolution Protocol (ARP) requests and verifies that each of these packets has a valid IP-to-MAC address binding before updating the local ARP cache and before forwarding...
|If STP is used, the Juniper EX switch must be configured to implement Rapid STP, or Multiple STP, where VLANs span multiple switches with redundant links.
|Spanning Tree Protocol (STP) is implemented on bridges and switches to prevent layer 2 loops when a broadcast domain spans multiple bridges and switches and when redundant links are provisioned to...
|The Juniper EX switch must be configured to verify two-way connectivity on all interswitch trunked interfaces.
|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...
|The Juniper EX switch must be configured to prune the default VLAN from all trunked interfaces that do not require it.
|All unassigned interfaces are placed into the default VLAN and devices connected to enabled, but unassigned interfaces can communicate within that VLAN. Although the default VLAN is not...
|The Juniper EX switch must not use the default VLAN for management traffic.
|By default, all unassigned interfaces are placed into the default VLAN and if used for management, could unintentionally expose sensitive traffic or protected resources to unauthorized devices.
|The Juniper EX switch must be configured to assign all disabled access interfaces to an unused VLAN.
|It is possible that a disabled access interface that is assigned to a user or management VLAN becomes enabled by accident or by an attacker and as a result gains access to that VLAN as a member.
|The Juniper EX switch must not be configured with VLANs used for L2 control traffic assigned to any host-facing access interface.
|In a switched Ethernet network, some protocols use L2 Protocol Data Units (PDU) to communicate in-band management or other control information. This control traffic is inappropriate for...
|The Juniper EX switch must not have a native VLAN ID assigned, or have a unique native VLAN ID, for all 802.1q trunk links.
|By default, Juniper switches do not assign a native VLAN to any trunked interface. Allowing trunked interfaces to accept untagged data packets may unintentionally expose VLANs to unauthorized...
|The Juniper EX switch must be configured to set all user-facing or untrusted ports as access interfaces.
|Configuring user-facing or untrusted interfaces as trunked may expose network traffic to an unauthorized, or unintended, connected endpoint. Access interfaces can belong to a single VLAN rather...
|The Juniper EX switch must be configured to enable DHCP snooping for all user VLANs to validate DHCP messages from untrusted sources.
|In an enterprise network, devices under administrative control are trusted sources. These devices include the switches, routers, and servers in the network. Host interfaces and unknown DHCP...
|The Juniper EX switch must be configured not to forward unknown unicast traffic to access interfaces.
|Access layer switches use the Content Addressable Memory (CAM) table to direct traffic to specific interfaces based on the VLAN number and the destination MAC address of the frame. When a router...
|The Juniper EX switch must be configured to enable STP Loop Protection on all non-designated STP switch ports.
|The Spanning Tree Protocol (STP) Loop Protection feature provides additional protection against STP loops. An STP loop is created when an STP blocking port in a redundant topology erroneously...
|The Juniper EX switch must be configured to enable BPDU Protection on all user-facing or untrusted access switch ports.
|If a rogue switch is introduced into the topology and transmits a Bridge Protocol Data Unit (BPDU) with a lower bridge priority than the existing root bridge, it will become the new root bridge...
|The Juniper EX switch must be configured to permit authorized users to remotely view, in real time, all content related to an established user session from a component separate from the layer 2 switch.
|Without the capability to remotely view/hear all content related to a user session, investigations into suspicious user activity would be hampered. Real-time monitoring allows authorized personnel...
|The Juniper EX switch must be configured to permit authorized users to select a user session to capture.
|Without the capability to select a user session to capture/record or view/hear, investigations into suspicious or harmful events would be hampered by the volume of information captured. The volume...
|The Juniper EX switch must be configured to manage excess bandwidth to limit the effects of packet flooding types of denial of service (DoS) attacks.
|Denial of service is a condition when a resource is not available for legitimate users. Packet flooding DDoS attacks are referred to as volumetric attacks and have the objective of overloading a...
|The Juniper layer 2 switch must be configured to disable all dynamic VLAN registration protocols.
|Dynamic VLAN registration protocols provide centralized management of VLAN domains, which can reduce administration in a switched network. Interfaces are assigned to VLANs and the VLAN is...
|The Juniper EX switch must be configured to enable Storm Control on all host-facing access interfaces.
|A traffic storm occurs when packets flood a LAN, creating excessive traffic and degrading network performance. Traffic storm control prevents network disruption by suppressing ingress traffic when...
|The Juniper EX switch must be configured to enable IGMP or MLD Snooping on all VLANs.
|IGMP and MLD snooping provides a way to constrain multicast traffic at layer 2. By monitoring the IGMP or MLD membership reports sent by hosts within a VLAN, the snooping application can set up...
|The Juniper EX switch must be configured to enable Root Protection on all interfaces connecting to access layer switches and hosts.
|Spanning Tree Protocol (STP) does not provide any means for the network administrator to securely enforce the topology of the switched network. Any switch can be the root bridge in a network....
|The Juniper EX switch must not have any access interfaces assigned to a VLAN configured as native for any trunked interface.
|Trunked interfaces without an assigned native VLAN do not accept untagged data packets. Allowing trunked interfaces to accept untagged data packets may unintentionally expose VLANs to unauthorized...