Router Security Requirements Guide

The Router Security Requirements Guide (SRG) is published as a tool to improve the security of Department of Defense (DoD) information systems. The requirements are derived from the NIST 800-53 and related documents. Comments or proposed revisions to this document should be sent via e-mail to the following address: [email protected]

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Version / Release: V3R6

Published: 2020-06-30

Updated At: 2020-08-15 20:25:42

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    Vuln Rule Version CCI Severity Title Description Status Finding Details Comments
    SV-69975r2_rule SRG-NET-000019-RTR-000002 CCI-001414 MEDIUM The perimeter router must be configured to enforce approved authorizations for controlling the flow of information between interconnected networks in accordance with applicable policy. Information flow control regulates authorized information to travel within a network and between interconnected networks. Controlling the flow of network traffic is critical so it does not introduce any unacceptable risk to the network infrastructure or d
    SV-69977r2_rule SRG-NET-000019-RTR-000003 CCI-001414 MEDIUM The multicast router must be configured to disable Protocol Independent Multicast (PIM) on all interfaces that are not required to support multicast routing. If multicast traffic is forwarded beyond the intended boundary, it is possible that it can be intercepted by unauthorized or unintended personnel. Limiting where, within the network, a given multicast group's data is permitted to flow is an important firs
    SV-69981r2_rule SRG-NET-000019-RTR-000004 CCI-001414 MEDIUM The multicast router must be configured to bind a Protocol Independent Multicast (PIM) neighbor filter to interfaces that have PIM enabled. PIM is a routing protocol used to build multicast distribution trees for forwarding multicast traffic across the network infrastructure. PIM traffic must be limited to only known PIM neighbors by configuring and binding a PIM neighbor filter to those inte
    SV-69983r3_rule SRG-NET-000019-RTR-000005 CCI-001414 LOW The multicast edge router must be configured to establish boundaries for administratively scoped multicast traffic. If multicast traffic is forwarded beyond the intended boundary, it is possible that it can be intercepted by unauthorized or unintended personnel. Administrative scoped multicast addresses are locally assigned and are to be used exclusively by the enterp
    SV-69985r3_rule SRG-NET-000019-RTR-000007 CCI-001414 LOW The router must be configured to have all inactive interfaces disabled. An inactive interface is rarely monitored or controlled and may expose a network to an undetected attack on that interface. Unauthorized personnel with access to the communication facility could gain access to a router by connecting to a configured interf
    SV-69987r3_rule SRG-NET-000019-RTR-000009 CCI-001414 HIGH The perimeter router must be configured to not be a Border Gateway Protocol (BGP) peer to an alternate gateway service provider. ISPs use BGP to share route information with other autonomous systems (i.e. other ISPs and corporate networks). If the perimeter router was configured to BGP peer with an ISP, NIPRnet routes could be advertised to the ISP; thereby creating a backdoor con
    SV-69989r3_rule SRG-NET-000019-RTR-000010 CCI-001414 LOW The perimeter router must be configured to not redistribute static routes to an alternate gateway service provider into BGP or an IGP peering with the NIPRNet or to other autonomous systems. If the static routes to the alternate gateway are being redistributed into an Exterior Gateway Protocol or Interior Gateway Protocol to a NIPRNet gateway, this could make traffic on NIPRNet flow to that particular router and not to the Internet Access Poi
    SV-69993r2_rule SRG-NET-000019-RTR-000011 CCI-001414 MEDIUM The out-of-band management (OOBM) gateway router must be configured to have separate IGP instances for the managed network and management network. If the gateway router is not a dedicated device for the OOBM network, implementation of several safeguards for containment of management and production traffic boundaries must occur. Since the managed and management network are separate routing domains, c
    SV-69995r2_rule SRG-NET-000019-RTR-000012 CCI-001414 MEDIUM The out-of-band management (OOBM) gateway router must be configured to not redistribute routes between the management network routing domain and the managed network routing domain. If the gateway router is not a dedicated device for the OOBM network, several safeguards must be implemented for containment of management and production traffic boundaries; otherwise, it is possible that management traffic will not be separated from prod
    SV-70001r3_rule SRG-NET-000019-RTR-000013 CCI-001414 LOW The multicast Rendezvous Point (RP) router must be configured to filter Protocol Independent Multicast (PIM) Register messages received from the Designated Router (DR) for any undesirable multicast groups and sources. Real-time multicast traffic can entail multiple large flows of data. An attacker can flood a network segment with multicast packets, over-using the available bandwidth and thereby creating a denial-of-service (DoS) condition. Hence, it is imperative that
    SV-70003r3_rule SRG-NET-000019-RTR-000014 CCI-001414 LOW The multicast Rendezvous Point (RP) router must be configured to filter Protocol Independent Multicast (PIM) Join messages received from the Designated Router (DR) for any undesirable multicast groups. Real-time multicast traffic can entail multiple large flows of data. An attacker can flood a network segment with multicast packets, over-using the available bandwidth and thereby creating a denial-of-service (DoS) condition. Hence, it is imperative that
    SV-70011r3_rule SRG-NET-000230-RTR-000001 CCI-000366 MEDIUM The router must be configured to implement message authentication for all control plane protocols. A rogue router could send a fictitious routing update to convince a site's perimeter router to send traffic to an incorrect or even a rogue destination. This diverted traffic could be analyzed to learn confidential information about the site's network or
    SV-70013r3_rule SRG-NET-000230-RTR-000003 CCI-000366 MEDIUM The router must be configured to use keys with a duration not exceeding 180 days for authenticating routing protocol messages. If the keys used for routing protocol authentication are guessed, the malicious user could create havoc within the network by advertising incorrect routes and redirecting traffic. Some routing protocols allow the use of key chains for authentication. A ke
    SV-70015r4_rule SRG-NET-000205-RTR-000014 CCI-001094 HIGH The perimeter router must be configured to restrict it from accepting outbound IP packets that contain an illegitimate address in the source address field via egress filter or by enabling Unicast Reverse Path Forwarding (uRPF). A compromised host in an enclave can be used by a malicious platform to launch cyber attacks on third parties. This is a common practice in "botnets", which are a collection of compromised computers using malware to attack other computers or networks. DDo
    SV-70017r2_rule SRG-NET-000131-RTR-000035 CCI-000381 LOW The router must be configured to have all non-essential capabilities disabled. A compromised router 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 attacks by malicious users within the network. Preventing networ
    SV-70019r2_rule SRG-NET-000168-RTR-000077 CCI-000803 MEDIUM The router must be configured to use encryption for routing protocol authentication. A rogue router could send a fictitious routing update to convince a site's perimeter router to send traffic to an incorrect or even a rogue destination. This diverted traffic could be analyzed to learn confidential information about the site's network or
    SV-70021r3_rule SRG-NET-000168-RTR-000078 CCI-000803 MEDIUM The router must be configured to authenticate all routing protocol messages using NIST-validated FIPS 198-1 message authentication code algorithm. A rogue router could send a fictitious routing update to convince a site's perimeter router to send traffic to an incorrect or even a rogue destination. This diverted traffic could be analyzed to learn confidential information about the site's network or
    SV-70023r4_rule SRG-NET-000362-RTR-000124 CCI-002385 LOW The BGP router must be configured to enable the Generalized TTL Security Mechanism (GTSM). GTSM is designed to protect a router's IP-based control plane from DoS attacks. Many attacks focused on CPU load and line-card overload can be prevented by implementing GTSM on all Exterior Border Gateway Protocol speaking routers. GTSM is based on the
    SV-70027r3_rule SRG-NET-000205-RTR-000015 CCI-002403 MEDIUM The perimeter router must be configured to block all packets with any IP options. Packets with IP options are not fast switched and henceforth must be punted to the router processor. Hackers who initiate denial-of-service (DoS) attacks on routers commonly send large streams of packets with IP options. Dropping the packets with IP optio
    SV-70033r2_rule SRG-NET-000235-RTR-000114 CCI-001190 MEDIUM The router must be configured to stop forwarding traffic upon the failure of the following actions: system initialization, shutdown, or system abort. Failure to a known safe state helps prevent systems from failing to a state that may cause loss of data or unauthorized access to system resources. Routers that fail suddenly and with no incorporated failure state planning may leave the hosting system ava
    SV-70035r2_rule SRG-NET-000362-RTR-000110 CCI-002385 MEDIUM The router must be configured to protect against or limit the effects of denial-of-service (DoS) attacks by employing control plane protection. The Route Processor (RP) is critical to all network operations because it is the component used to build all forwarding paths for the data plane via control plane processes. It is also instrumental with ongoing network management functions that keep the r
    SV-70039r2_rule SRG-NET-000364-RTR-000109 CCI-002403 MEDIUM The perimeter router must be configured to only allow incoming communications from authorized sources to be routed to authorized destinations. Unrestricted traffic may contain malicious traffic that poses a threat to an enclave or to other connected networks. Additionally, unrestricted traffic may transit a network, which uses bandwidth and other resources. Traffic can be restricted directly by
    SV-70043r2_rule SRG-NET-000365-RTR-000112 CCI-001126 MEDIUM The router must be configured to fail securely in the event of an operational failure. If the router fails in an unsecure manner (open), unauthorized traffic originating externally to the enclave may enter or the device may permit unauthorized information release. Fail secure is a condition achieved by employing information system mechanism
    SV-92915r1_rule SRG-NET-000018-RTR-000001 CCI-001368 MEDIUM The router must be configured to enforce approved authorizations for controlling the flow of information within the network based on organization-defined information flow control policies. Information flow control regulates where information is allowed to travel within a network and between interconnected networks. The flow of all network traffic must be monitored and controlled so it does not introduce any unacceptable risk to the network
    SV-92917r2_rule SRG-NET-000131-RTR-000083 CCI-002403 MEDIUM The router must not be configured to have any feature enabled that calls home to the vendor. Call home services will routinely send data such as configuration and diagnostic information to the vendor for routine or emergency analysis and troubleshooting. There is a risk that transmission of sensitive data sent to unauthorized persons could result
    SV-92919r1_rule SRG-NET-000362-RTR-000109 CCI-002385 MEDIUM The router must not be configured to have any zero-touch deployment feature enabled when connected to an operational network. Network devices that are configured via a zero-touch deployment or auto-loading feature can have their startup configuration or image pushed to the device for installation via TFTP or Remote Copy (rcp). Loading an image or configuration file from the netw
    SV-92921r2_rule SRG-NET-000205-RTR-000001 CCI-001097 HIGH The router must be configured to restrict traffic destined to itself. The route processor handles traffic destined to the router—the key component used to build forwarding paths and is also instrumental with all network management functions. Hence, any disruption or DoS attack to the route processor can result in mission
    SV-92923r1_rule SRG-NET-000205-RTR-000002 CCI-001097 MEDIUM The router must be configured to drop all fragmented Internet Control Message Protocol (ICMP) packets destined to itself. Fragmented ICMP packets can be generated by hackers for DoS attacks such as Ping O' Death and Teardrop. It is imperative that all fragmented ICMP packets are dropped.
    SV-92925r1_rule SRG-NET-000362-RTR-000111 CCI-002385 MEDIUM The router must be configured to have Gratuitous ARP disabled on all external interfaces. A gratuitous ARP is an ARP broadcast in which the source and destination MAC addresses are the same. It is used to inform the network about a host IP address. A spoofed gratuitous ARP message can cause network mapping information to be stored incorrectly,
    SV-92927r1_rule SRG-NET-000362-RTR-000112 CCI-002385 LOW The router must be configured to have IP directed broadcast disabled on all interfaces. An IP directed broadcast is a datagram sent to the broadcast address of a subnet that is not directly attached to the sending machine. The directed broadcast is routed through the network as a unicast packet until it arrives at the target subnet, where it
    SV-92929r1_rule SRG-NET-000362-RTR-000113 CCI-002385 MEDIUM The router must be configured to have Internet Control Message Protocol (ICMP) unreachable notifications disabled on all external interfaces. The ICMP supports IP traffic by relaying information about paths, routes, and network conditions. Routers automatically send ICMP messages under a wide variety of conditions. Host unreachable ICMP messages are commonly used by attackers for network mappin
    SV-92931r1_rule SRG-NET-000362-RTR-000114 CCI-002385 MEDIUM The router must be configured to have Internet Control Message Protocol (ICMP) mask replies disabled on all external interfaces. The ICMP supports IP traffic by relaying information about paths, routes, and network conditions. Routers automatically send ICMP messages under a wide variety of conditions. Mask Reply ICMP messages are commonly used by attackers for network mapping and
    SV-92933r1_rule SRG-NET-000362-RTR-000115 CCI-002385 MEDIUM The router must be configured to have Internet Control Message Protocol (ICMP) redirects disabled on all external interfaces. The ICMP supports IP traffic by relaying information about paths, routes, and network conditions. Routers automatically send ICMP messages under a wide variety of conditions. Redirect ICMP messages are commonly used by attackers for network mapping and di
    SV-92935r1_rule SRG-NET-000078-RTR-000001 CCI-000134 LOW The router must be configured to log all packets that have been dropped. Auditing and logging are key components of any security architecture. It is essential for security personnel to know what is being done or attempted to be done, and by whom, to compile an accurate risk assessment. Auditing the actions on network devices p
    SV-92937r1_rule SRG-NET-000076-RTR-000001 CCI-000132 MEDIUM The router must be configured to produce audit records containing information to establish where the events occurred. Without establishing where events occurred, it is impossible to establish, correlate, and investigate the events leading up to an outage or attack. In order to compile an accurate risk assessment and provide forensic analysis, it is essential for securit
    SV-92939r1_rule SRG-NET-000077-RTR-000001 CCI-000133 MEDIUM The router must be configured to produce audit records containing information to establish the source of the events. Without establishing the source of the event, it is impossible to establish, correlate, and investigate the events leading up to an outage or attack. In order to compile an accurate risk assessment and provide forensic analysis, security personnel need t
    SV-92941r1_rule SRG-NET-000019-RTR-000001 CCI-001414 LOW The router must be configured to disable the auxiliary port unless it is connected to a secured modem providing encryption and authentication. The use of POTS lines to modems connecting to network devices provides clear text of authentication traffic over commercial circuits that could be captured and used to compromise the network. Additional war dial attacks on the device could degrade the dev
    SV-92943r1_rule SRG-NET-000202-RTR-000001 CCI-001109 HIGH The perimeter router must be configured to deny network traffic by default and allow network traffic by exception. A deny-all, permit-by-exception network communications traffic policy ensures that only connections that are essential and approved are allowed. This requirement applies to both inbound and outbound network communications traffic. All inbound and outboun
    SV-92945r3_rule SRG-NET-000364-RTR-000110 CCI-002403 MEDIUM The perimeter router must be configured to block inbound packets with source Bogon IP address prefixes. Bogons include IP packets on the public Internet that contain addresses that are not in any range allocated or delegated by the Internet Assigned Numbers Authority (IANA) or a delegated regional Internet registry (RIR) and allowed for public Internet use.
    SV-92947r1_rule SRG-NET-000019-RTR-000008 CCI-001414 HIGH The perimeter router must be configured to protect an enclave connected to an alternate gateway by using an inbound filter that only permits packets with destination addresses within the sites address space. Enclaves with alternate gateway connections must take additional steps to ensure there is no compromise on the enclave network or NIPRNet. Without verifying the destination address of traffic coming from the site's alternate gateway, the perimeter router
    SV-92949r2_rule SRG-NET-000205-RTR-000003 CCI-001097 MEDIUM The perimeter router must be configured to filter traffic destined to the enclave in accordance with the guidelines contained in DoD Instruction 8551.1. Vulnerability assessments must be reviewed by the System Administrator, and protocols must be approved by the Information Assurance (IA) staff before entering the enclave. Access control lists (ACLs) are the first line of defense in a layered security ap
    SV-92951r1_rule SRG-NET-000205-RTR-000004 CCI-001097 MEDIUM The perimeter router must be configured to filter ingress traffic at the external interface on an inbound direction. Access lists are used to separate data traffic into that which it will route (permitted packets) and that which it will not route (denied packets). Secure configuration of routers makes use of access lists for restricting access to services on the router
    SV-92953r2_rule SRG-NET-000205-RTR-000005 CCI-001097 MEDIUM The perimeter router must be configured to filter egress traffic at the internal interface on an inbound direction. Access lists are used to separate data traffic into that which it will route (permitted packets) and that which it will not route (denied packets). Secure configuration of routers makes use of access lists for restricting access to services on the router
    SV-92955r1_rule SRG-NET-000364-RTR-000111 CCI-002403 LOW The perimeter router must be configured to have Link Layer Discovery Protocols (LLDPs) disabled on all external interfaces. LLDPs are primarily used to obtain protocol addresses of neighboring devices and discover platform capabilities of those devices. Use of SNMP with the LLDP Management Information Base (MIB) allows network management applications to learn the device type a
    SV-92957r1_rule SRG-NET-000364-RTR-000112 CCI-002403 MEDIUM The perimeter router must be configured to have Proxy ARP disabled on all external interfaces. When Proxy ARP is enabled on a Cisco router, it allows that router to extend the network (at Layer 2) across multiple interfaces (LAN segments). Because proxy ARP allows hosts from different LAN segments to look like they are on the same segment, proxy AR
    SV-92959r1_rule SRG-NET-000364-RTR-000113 CCI-001097 MEDIUM The perimeter router must be configured to block all outbound management traffic. For in-band management, the management network must have its own subnet in order to enforce control and access boundaries provided by Layer 3 network nodes, such as routers and firewalls. Management traffic between the managed network elements and the man
    SV-92961r1_rule SRG-NET-000205-RTR-000009 CCI-001097 MEDIUM The out-of-band management (OOBM) gateway must be configured to transport management traffic to the Network Operations Center (NOC) via dedicated circuit, MPLS/VPN service, or IPsec tunnel. Using dedicated paths, the OOBM backbone connects the OOBM gateway routers located at the edge of the managed network and at the NOC. Dedicated links can be deployed using provisioned circuits or MPLS Layer 2 and Layer 3 VPN services or implementing a sec
    SV-92963r1_rule SRG-NET-000205-RTR-000010 CCI-001097 MEDIUM The out-of-band management (OOBM) gateway router must be configured to forward only authorized management traffic to the Network Operations Center (NOC). The OOBM network is an IP network used exclusively for the transport of OAM&P data from the network being managed to the OSS components located at the NOC. Its design provides connectivity to each managed network device, enabling network management traffi
    SV-92969r1_rule SRG-NET-000205-RTR-000013 CCI-001097 MEDIUM The router providing connectivity to the NOC must be configured to forward all in-band management traffic via an IPsec tunnel. When the production network is managed in-band, the management network could be housed at a NOC that is located remotely at single or multiple interconnected sites. NOC interconnectivity, as well as connectivity between the NOC and the managed network, mu
    SV-92971r2_rule SRG-NET-000230-RTR-000002 CCI-000366 MEDIUM The BGP router must be configured to use a unique key for each autonomous system (AS) that it peers with. If the same keys are used between eBGP neighbors, the chance of a hacker compromising any of the BGP sessions increases. It is possible that a malicious user exists in one autonomous system who would know the key used for the eBGP session. This user would
    SV-92973r1_rule SRG-NET-000018-RTR-000002 CCI-001368 MEDIUM The BGP router must be configured to reject inbound route advertisements for any Bogon prefixes. Accepting route advertisements for Bogon prefixes can result in the local autonomous system (AS) becoming a transit for malicious traffic as it will in turn advertise these prefixes to neighbor autonomous systems.
    SV-92975r1_rule SRG-NET-000018-RTR-000003 CCI-001368 MEDIUM The BGP router must be configured to reject inbound route advertisements for any prefixes belonging to the local autonomous system (AS). Accepting route advertisements belonging to the local AS can result in traffic looping or being black holed, or at a minimum using a non-optimized path.
    SV-92977r1_rule SRG-NET-000018-RTR-000004 CCI-001368 MEDIUM The BGP router must be configured to reject inbound route advertisements from a customer edge (CE) router for prefixes that are not allocated to that customer. As a best practice, a service provider should only accept customer prefixes that have been assigned to that customer and any peering autonomous systems. A multi-homed customer with BGP speaking routers connected to the Internet or other external networks
    SV-92979r2_rule SRG-NET-000018-RTR-000005 CCI-001368 MEDIUM The BGP router must be configured to reject outbound route advertisements for any prefixes that do not belong to any customers or the local autonomous system (AS). Advertisement of routes by an autonomous system for networks that do not belong to any of its customers pulls traffic away from the authorized network. This causes a denial of service (DoS) on the network that allocated the block of addresses and may caus
    SV-92981r1_rule SRG-NET-000205-RTR-000006 CCI-001097 MEDIUM The BGP router must be configured to reject outbound route advertisements for any prefixes belonging to the IP core. Outbound route advertisements belonging to the core can result in traffic either looping or being black holed, or at a minimum, using a non-optimized path.
    SV-92983r1_rule SRG-NET-000018-RTR-000006 CCI-000032 LOW The BGP router must be configured to reject route advertisements from BGP peers that do not list their autonomous system (AS) number as the first AS in the AS_PATH attribute. Verifying the path a route has traversed will ensure the IP core is not used as a transit network for unauthorized or possibly even Internet traffic. All autonomous system boundary routers (ASBRs) must ensure updates received from eBGP peers list their AS
    SV-92985r1_rule SRG-NET-000362-RTR-000117 CCI-002385 MEDIUM The BGP router must be configured to use the maximum prefixes feature to protect against route table flooding and prefix de-aggregation attacks. The effects of prefix de-aggregation can degrade router performance due to the size of routing tables and also result in black-holing legitimate traffic. Initiated by an attacker or a misconfigured router, prefix de-aggregation occurs when the announcemen
    SV-92987r2_rule SRG-NET-000362-RTR-000118 CCI-002385 LOW The BGP router must be configured to limit the prefix size on any inbound route advertisement to /24 or the least significant prefixes issued to the customer. The effects of prefix de-aggregation can degrade router performance due to the size of routing tables and also result in black-holing legitimate traffic. Initiated by an attacker or a misconfigured router, prefix de-aggregation occurs when the announcemen
    SV-92989r1_rule SRG-NET-000512-RTR-000001 CCI-000366 LOW The BGP router must be configured to use its loopback address as the source address for iBGP peering sessions. Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability of the BGP routers. It is easier to construct appropriate ingress filters for router management plane traffic destined to the netwo
    SV-92991r1_rule SRG-NET-000512-RTR-000002 CCI-000366 LOW The MPLS router must be configured to use its loopback address as the source address for LDP peering sessions. Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability of backbone routers. It is easier to construct appropriate ingress filters for router management plane traffic destined to the netw
    SV-92993r1_rule SRG-NET-000512-RTR-000003 CCI-000366 LOW The MPLS router must be configured to synchronize IGP and LDP to minimize packet loss when an IGP adjacency is established prior to LDP peers completing label exchange. Packet loss can occur when an IGP adjacency is established and the router begins forwarding packets using the new adjacency before the LDP label exchange completes between the peers on that link. Packet loss can also occur if an LDP session closes and the
    SV-92995r2_rule SRG-NET-000193-RTR-000001 CCI-001095 LOW The MPLS router with RSVP-TE enabled must be configured with message pacing or refresh reduction to adjust maximum number of RSVP messages to an output queue based on the link speed and input queue size of adjacent core routers. RSVP-TE can be used to perform constraint-based routing when building LSP tunnels within the network core that will support QoS and traffic engineering requirements. RSVP-TE is also used to enable MPLS Fast Reroute, a network restoration mechanism that wi
    SV-92997r2_rule SRG-NET-000512-RTR-000004 CCI-000366 MEDIUM The MPLS router must be configured to have TTL Propagation disabled. The head end of the label-switched path (LSP), the label edge router (LER) will decrement the IP packet's time-to-live (TTL) value by one and then copy the value to the MPLS TTL field. At each label-switched router (LSR) hop, the MPLS TTL value is decreme
    SV-92999r2_rule SRG-NET-000512-RTR-000005 CCI-000366 HIGH The PE router must be configured to have each Virtual Routing and Forwarding (VRF) instance bound to the appropriate physical or logical interfaces to maintain traffic separation between all MPLS L3VPNs. The primary security model for an MPLS L3VPN infrastructure is traffic separation. The service provider must guarantee the customer that traffic from one VPN does not leak into another VPN or into the core, and that core traffic must not leak into any VPN
    SV-93001r1_rule SRG-NET-000512-RTR-000006 CCI-000366 HIGH The PE router must be configured to have each Virtual Routing and Forwarding (VRF) instance with the appropriate Route Target (RT). The primary security model for an MPLS L3VPN as well as a VRF-lite infrastructure is traffic separation. Each interface can only be associated to one VRF, which is the fundamental framework for traffic separation. Forwarding decisions are made based on th
    SV-93003r1_rule SRG-NET-000512-RTR-000007 CCI-000366 MEDIUM The PE router must be configured to have each VRF with the appropriate Route Distinguisher (RD). An RD provides uniqueness to the customer address spaces within the MPLS L3VPN infrastructure. The concept of the VPN-IPv4 and VPN-IPv6 address families consists of the RD prepended before the IP address. Hence, if the same IP prefix is used in several di
    SV-93005r1_rule SRG-NET-000343-RTR-000001 CCI-001958 MEDIUM The PE router providing MPLS Layer 2 Virtual Private Network (L2VPN) services must be configured to authenticate targeted Label Distribution Protocol (LDP) sessions used to exchange virtual circuit (VC) information using a FIPS-approved message authentication code algorithm. LDP provides the signaling required for setting up and tearing down pseudowires (virtual circuits used to transport Layer 2 frames) across an MPLS IP core network. Using a targeted LDP session, each PE router advertises a virtual circuit label mapping tha
    SV-93007r2_rule SRG-NET-000512-RTR-000008 CCI-000366 HIGH The PE router providing MPLS Virtual Private Wire Service (VPWS) must be configured to have the appropriate virtual circuit identification (VC ID) for each attachment circuit. VPWS is an L2VPN technology that provides a virtual circuit between two PE routers to forward Layer 2 frames between two customer-edge routers or switches through an MPLS-enabled IP core. The ingress PE router (virtual circuit head-end) encapsulates Ether
    SV-93009r1_rule SRG-NET-000512-RTR-000009 CCI-000366 HIGH The PE router providing Virtual Private LAN Services (VPLS) must be configured to have all attachment circuits defined to the virtual forwarding instance (VFI) with the globally unique VPN ID assigned for each customer VLAN. VPLS defines an architecture that delivers Ethernet multipoint services over an MPLS network. Customer Layer 2 frames are forwarded across the MPLS core via pseudowires using IEEE 802.1q Ethernet bridging principles. A pseudowire is a virtual bidirectiona
    SV-93011r1_rule SRG-NET-000512-RTR-000010 CCI-000366 LOW The PE router must be configured to enforce the split-horizon rule for all pseudowires within a Virtual Private LAN Services (VPLS) bridge domain. A virtual forwarding instance (VFI) must be created on each participating PE router for each customer VLAN using VPLS for carrier Ethernet services. The VFI specifies the VPN ID of a VPLS domain, the addresses of other PE routers in the domain, and the ty
    SV-93013r2_rule SRG-NET-000193-RTR-000002 CCI-001095 MEDIUM The PE router providing Virtual Private LAN Services (VPLS) must be configured to have traffic storm control thresholds on CE-facing interfaces. A traffic storm occurs when packets flood a VPLS bridge, creating excessive traffic and degrading network performance. Traffic storm control prevents VPLS bridge disruption by suppressing traffic when the number of packets reaches configured threshold lev
    SV-93015r1_rule SRG-NET-000362-RTR-000119 CCI-002385 LOW The PE router must be configured to implement Internet Group Management Protocol (IGMP) or Multicast Listener Discovery (MLD) snooping for each Virtual Private LAN Services (VPLS) bridge domain. IGMP snooping provides a way to constrain multicast traffic at Layer 2. By monitoring the IGMP membership reports sent by hosts within the bridge domain, the snooping application can set up Layer 2 multicast forwarding tables to deliver traffic only to po
    SV-93017r1_rule SRG-NET-000192-RTR-000002 CCI-001094 MEDIUM The PE router must be configured to limit the number of MAC addresses it can learn for each Virtual Private LAN Services (VPLS) bridge domain. VPLS defines an architecture that delivers Ethernet multipoint services over an MPLS network. Customer Layer 2 frames are forwarded across the MPLS core via pseudowires using IEEE 802.1q Ethernet bridging principles. A pseudowire is a virtual bidirectiona
    SV-93019r1_rule SRG-NET-000205-RTR-000007 CCI-001097 HIGH The PE router must be configured to block any traffic that is destined to IP core infrastructure. IP/MPLS networks providing VPN and transit services must provide, at the least, the same level of protection against denial-of-service (DoS) attacks and intrusions as Layer 2 networks. Although the IP core network elements are hidden, security should neve
    SV-93021r2_rule SRG-NET-000205-RTR-000008 CCI-001097 MEDIUM The PE router must be configured with Unicast Reverse Path Forwarding (uRPF) loose mode enabled on all CE-facing interfaces.. The uRPF feature is a defense against spoofing and denial-of-service (DoS) attacks by verifying if the source address of any ingress packet is reachable. To mitigate attacks that rely on forged source addresses, all provider edge routers must enable uRPF
    SV-93023r2_rule SRG-NET-000205-RTR-000016 CCI-002403 MEDIUM The PE router must be configured to ignore or block all packets with any IP options. Packets with IP options are not fast switched and therefore must be punted to the router processor. Hackers who initiate denial-of-service (DoS) attacks on routers commonly send large streams of packets with IP options. Dropping the packets with IP option
    SV-93025r2_rule SRG-NET-000193-RTR-000113 CCI-001095 LOW The PE router must be configured to enforce a Quality-of-Service (QoS) policy in accordance with the QoS DoDIN Technical Profile. Different applications have unique requirements and toleration levels for delay, jitter, bandwidth, packet loss, and availability. To manage the multitude of applications and services, a network requires a QoS framework to differentiate traffic and provid
    SV-93027r3_rule SRG-NET-000193-RTR-000114 CCI-001095 LOW The P router must be configured to enforce a Quality-of-Service (QoS) policy in accordance with the QoS GIG Technical Profile. Different applications have unique requirements and toleration levels for delay, jitter, bandwidth, packet loss, and availability. To manage the multitude of applications and services, a network requires a QoS framework to differentiate traffic and provid
    SV-93031r2_rule SRG-NET-000193-RTR-000112 CCI-001095 MEDIUM The PE router must be configured to enforce a Quality-of-Service (QoS) policy to limit the effects of packet flooding denial-of-service (DoS) attacks. DoS is a condition when a resource is not available for legitimate users. Packet flooding distributed denial-of-service (DDoS) attacks are referred to as volumetric attacks and have the objective of overloading a network or circuit to deny or seriously de
    SV-93033r1_rule SRG-NET-000362-RTR-000120 CCI-002385 LOW The multicast Rendezvous Point (RP) router must be configured to limit the multicast forwarding cache so that its resources are not saturated by managing an overwhelming number of Protocol Independent Multicast (PIM) and Multicast Source Discovery Protocol (MSDP) source-active entries. MSDP peering between networks enables sharing of multicast source information. Enclaves with an existing multicast topology using PIM-SM can configure their RP routers to peer with MSDP routers. As a first step of defense against a denial-of-service (DoS)
    SV-93035r2_rule SRG-NET-000362-RTR-000121 CCI-002385 MEDIUM The multicast Rendezvous Point (RP) must be configured to rate limit the number of Protocol Independent Multicast (PIM) Register messages. When a new source starts transmitting in a PIM Sparse Mode network, the DR will encapsulate the multicast packets into register messages and forward them to the RP using unicast. This process can be taxing on the CPU for both the DR and the RP if the sour
    SV-93037r2_rule SRG-NET-000364-RTR-000114 CCI-002403 LOW The multicast Designated Router (DR) must be configured to filter the Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD) Report messages to allow hosts to join only multicast groups that have been approved by the organization. Real-time multicast traffic can entail multiple large flows of data. Large unicast flows tend to be fairly isolated (i.e., someone doing a file download here or there), whereas multicast can have broader impact on bandwidth consumption, resulting in extre
    SV-93039r2_rule SRG-NET-000364-RTR-000115 CCI-002403 MEDIUM The multicast Designated Router (DR) must be configured to filter the Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD) Report messages to allow hosts to join a multicast group only from sources that have been approved by the organization. Real-time multicast traffic can entail multiple large flows of data. Large unicast flows tend to be fairly isolated (i.e., someone doing a file download here or there), whereas multicast can have broader impact on bandwidth consumption, resulting in extre
    SV-93041r1_rule SRG-NET-000362-RTR-000122 CCI-002385 MEDIUM The multicast Designated Router (DR) must be configured to limit the number of mroute states resulting from Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD) Host Membership Reports. The current multicast paradigm can let any host join any multicast group at any time by sending an IGMP or MLD membership report to the DR. In a Protocol Independent Multicast (PIM) Sparse Mode network, the DR will send a PIM Join message for the group to
    SV-93043r1_rule SRG-NET-000362-RTR-000123 CCI-002385 MEDIUM The multicast Designated Router (DR) must be configured to increase the shortest-path tree (SPT) threshold or set it to infinity to minimalize source-group (S, G) state within the multicast topology where Any Source Multicast (ASM) is deployed. ASM can have many sources for the same groups (many-to-many). For many receivers, the path via the RP may not be ideal compared with the shortest path from the source to the receiver. By default, the last-hop router will initiate a switch from the shared
    SV-93045r1_rule SRG-NET-000364-RTR-000116 CCI-002403 MEDIUM The Multicast Source Discovery Protocol (MSDP) router must be configured to only accept MSDP packets from known MSDP peers. MSDP peering with customer network routers presents additional risks to the DISN Core, whether from a rogue or misconfigured MSDP-enabled router. To guard against an attack from malicious MSDP traffic, the receive path or interface filter for all MSDP-ena
    SV-93047r1_rule SRG-NET-000343-RTR-000002 CCI-001958 MEDIUM The Multicast Source Discovery Protocol (MSDP) router must be configured to authenticate all received MSDP packets. MSDP peering with customer network routers presents additional risks to the core, whether from a rogue or misconfigured MSDP-enabled router. MSDP password authentication is used to validate each segment sent on the TCP connection between MSDP peers, prote
    SV-93049r2_rule SRG-NET-000018-RTR-000007 CCI-001368 LOW The Multicast Source Discovery Protocol (MSDP) router must be configured to filter received source-active multicast advertisements for any undesirable multicast groups and sources. The interoperability of BGP extensions for interdomain multicast routing and MSDP enables seamless connectivity of multicast domains between autonomous systems. MP-BGP advertises the unicast prefixes of the multicast sources used by Protocol Independent M
    SV-93051r1_rule SRG-NET-000018-RTR-000008 CCI-001368 LOW The Multicast Source Discovery Protocol (MSDP) router must be configured to filter source-active multicast advertisements to external MSDP peers to avoid global visibility of local-only multicast sources and groups. To avoid global visibility of local information, there are a number of source-group (S, G) states in a PIM-SM domain that must not be leaked to another domain, such as multicast sources with private address, administratively scoped multicast addresses, an
    SV-93053r1_rule SRG-NET-000018-RTR-000009 CCI-001368 LOW The MSDP router must be configured to limit the amount of source-active messages it accepts on per-peer basis. To reduce any risk of a denial-of-service (DoS) attack from a rogue or misconfigured MSDP router, the router must be configured to limit the number of source-active messages it accepts from each peer.
    SV-93055r1_rule SRG-NET-000512-RTR-000011 CCI-000366 LOW The Multicast Source Discovery Protocol (MSDP) router must be configured to use its loopback address as the source address when originating MSDP traffic. Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability of MSDP routers. It is easier to construct appropriate ingress filters for router management plane traffic destined to the network
    SV-93057r2_rule SRG-NET-000205-RTR-000012 CCI-001097 MEDIUM The router must be configured to only permit management traffic that ingresses and egresses the OOBM interface. The OOBM access switch 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 interfac
    SV-93063r1_rule SRG-NET-000205-RTR-000011 CCI-001097 MEDIUM The out-of-band management (OOBM) gateway router must be configured to block any traffic destined to itself that is not sourced from the OOBM network or the NOC. If the gateway router is not a dedicated device for the OOBM network, several safeguards must be implemented for containment of management and production traffic boundaries. It is imperative that hosts from the managed network are not able to access the O
    SV-102345r2_rule SRG-NET-000018-RTR-000010 CCI-000032 LOW The BGP router must be configured to reject route advertisements from CE routers with an originating AS in the AS_PATH attribute that does not belong to that customer. Verifying the path a route has traversed will ensure that the local AS is not used as a transit network for unauthorized traffic. To ensure that the local AS does not carry any prefixes that do not belong to any customers, all PE routers must be configure
    SV-109199r1_rule SRG-NET-000512-RTR-000100 CCI-000366 MEDIUM The router must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. Configuring the network device to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive securit
    SV-110187r1_rule SRG-NET-000512-RTR-000012 CCI-000366 LOW The router must be configured to advertise a hop limit of at least 32 in Router Advertisement messages for IPv6 stateless auto-configuration deployments. The Neighbor Discovery protocol allows a hop limit value to be advertised by routers in a Router Advertisement message being used by hosts instead of the standardized default value. If a very small value was configured and advertised to hosts on the LAN s
    SV-110189r1_rule SRG-NET-000512-RTR-000013 CCI-000366 MEDIUM The router must not be configured to use IPv6 Site Local Unicast addresses. As currently defined, site local addresses are ambiguous and can be present in multiple sites. The address itself does not contain any indication of the site to which it belongs. The use of site-local addresses has the potential to adversely affect networ
    SV-110191r1_rule SRG-NET-000512-RTR-000014 CCI-000366 MEDIUM The perimeter router must be configured to suppress Router Advertisements on all external IPv6-enabled interfaces. Many of the known attacks in stateless autoconfiguration are defined in RFC 3756 were present in IPv4 ARP attacks. To mitigate these vulnerabilities, links that have no hosts connected such as the interface connecting to external gateways must be configur
    SV-110193r1_rule SRG-NET-000364-RTR-000200 CCI-002403 MEDIUM The perimeter router must be configured to drop IPv6 undetermined transport packets. One of the fragmentation weaknesses known in IPv6 is the undetermined transport packet. This packet contains an undetermined protocol due to fragmentation. Depending on the length of the IPv6 extension header chain, the initial fragment may not contain th
    SV-110195r1_rule SRG-NET-000364-RTR-000201 CCI-002403 MEDIUM The perimeter router must be configured drop IPv6 packets with a Routing Header type 0, 1, or 3255. The routing header can be used maliciously to send a packet through a path where less robust security is in place, rather than through the presumably preferred path of routing protocols. Use of the routing extension header has few legitimate uses other th
    SV-110197r1_rule SRG-NET-000364-RTR-000202 CCI-002403 MEDIUM The perimeter router must be configured to drop IPv6 packets containing a Hop-by-Hop header with invalid option type values. These options are intended to be for the Destination Options header only. The optional and extensible natures of the IPv6 extension headers require higher scrutiny since many implementations do not always drop packets with headers that it cannot recognize
    SV-110199r1_rule SRG-NET-000364-RTR-000203 CCI-002403 MEDIUM The perimeter router must be configured to drop IPv6 packets containing a Destination Option header with invalid option type values. These options are intended to be for the Hop-by-Hop header only. The optional and extensible natures of the IPv6 extension headers require higher scrutiny since many implementations do not always drop packets with headers that it cannot recognize. Hence,
    SV-110201r1_rule SRG-NET-000364-RTR-000204 CCI-002403 MEDIUM The perimeter router must be configured to drop IPv6 packets containing an extension header with the Endpoint Identification option. The optional and extensible natures of the IPv6 extension headers require higher scrutiny since many implementations do not always drop packets with headers that it cannot recognize, and hence could cause a Denial-of-Service on the target device. In addit
    SV-110203r1_rule SRG-NET-000364-RTR-000205 CCI-002403 MEDIUM The perimeter router must be configured to drop IPv6 packets containing the NSAP address option within Destination Option header. The optional and extensible natures of the IPv6 extension headers require higher scrutiny since many implementations do not always drop packets with headers that it cannot recognize, and hence could cause a Denial-of-Service on the target device. In addit
    SV-110205r1_rule SRG-NET-000364-RTR-000206 CCI-002403 MEDIUM The perimeter router must be configured to drop IPv6 packets containing a Hop-by-Hop or Destination Option extension header with an undefined option type. The optional and extensible natures of the IPv6 extension headers require higher scrutiny since many implementations do not always drop packets with headers that it cannot recognize, and hence could cause a Denial-of-Service on the target device. In addit