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RFC7780 - Transparent Interconnection of Lots of Links (TRILL): Clarifications, Corrections, and Updates
Since the publication of the TRILL (Transparent Interconnection of Lots of Links) base protocol in 2011, active development and deployment of TRILL have revealed errata in RFC 6325 and areas that could use clarifications or updates. RFC 7177, RFC 7357, and an intended replacement of RFC 6439 provide clarifications and updates with respect to adjacency, the TRILL ESADI (End Station Address Distribution Information) protocol, and Appointed Forwarders, respectively. This document provides other known clarifications, corrections, and updates. It obsoletes RFC 7180 (the previous "TRILL clarifications, corrections, and updates" RFC), and it updates RFCs 6325, 7177, and 7179.
RFC7781 - Transparent Interconnection of Lots of Links (TRILL): Pseudo-Nickname for Active-Active Access
The IETF TRILL (Transparent Interconnection of Lots of Links) protocol provides support for flow-level multipathing for both unicast and multi-destination traffic in networks with arbitrary topology. Active-active access at the TRILL edge is the extension of these characteristics to end stations that are multiply connected to a TRILL campus as discussed in RFC 7379. In this document, the edge RBridge (Routing Bridge, or TRILL switch) group providing active-active access to such an end station is represented as a virtual RBridge. Based on the concept of the virtual RBridge, along with its pseudo-nickname, this document specifies a method for TRILL active-active access by such end stations.
RFC7782 - Transparent Interconnection of Lots of Links (TRILL) Active-Active Edge Using Multiple MAC Attachments
TRILL (Transparent Interconnection of Lots of Links) active-active service provides end stations with flow-level load balance and resilience against link failures at the edge of TRILL campuses, as described in RFC 7379.
This document specifies a method by which member RBridges (also referred to as Routing Bridges or TRILL switches) in an active-active edge RBridge group use their own nicknames as ingress RBridge nicknames to encapsulate frames from attached end systems. Thus, remote edge RBridges (who are not in the group) will see one host Media Access Control (MAC) address being associated with the multiple RBridges in the group. Such remote edge RBridges are required to maintain all those associations (i.e., MAC attachments) and to not flip-flop among them (as would occur prior to the implementation of this specification). The design goals of this specification are discussed herein.
RFC7783 - Coordinated Multicast Trees (CMT) for Transparent Interconnection of Lots of Links (TRILL)
TRILL (Transparent Interconnection of Lots of Links) facilitates loop-free connectivity to non-TRILL networks via a choice of an Appointed Forwarder for a set of VLANs. Appointed Forwarders provide VLAN-based load sharing with an active-standby model. High-performance applications require an active-active load-sharing model. The active-active load-sharing model can be accomplished by representing any given non-TRILL network with a single virtual RBridge (also referred to as a virtual Routing Bridge or virtual TRILL switch). Virtual representation of the non-TRILL network with a single RBridge poses serious challenges in multi-destination RPF (Reverse Path Forwarding) check calculations. This document specifies required enhancements to build Coordinated Multicast Trees (CMT) within the TRILL campus to solve related RPF issues. CMT, which only requires a software upgrade, provides flexibility to RBridges in selecting a desired path of association to a given TRILL multi-destination distribution tree. This document updates RFC 6325.
RFC7784 - Transparent Interconnection of Lots of Links (TRILL) Operations, Administration, and Maintenance (OAM) MIB
This document specifies the MIB for the OAM (Operations, Administration, and Maintenance) objects for IETF TRILL (Transparent Interconnection of Lots of Links).
RFC7956 - Transparent Interconnection of Lots of Links (TRILL) Distributed Layer 3 Gateway
The base TRILL (Transparent Interconnection of Lots of Links) protocol provides optimal pair-wise data frame forwarding for Layer 2 intra-subnet traffic but not for Layer 3 inter-subnet traffic. A centralized gateway solution is typically used for Layer 3 inter-subnet traffic forwarding but has the following issues:
1. Sub-optimum forwarding paths for inter-subnet traffic.
2. A centralized gateway that may need to support a very large number of gateway interfaces in a Data Center, one per tenant per Data Label used by that tenant, to provide interconnect functionality for all the Layer 2 Virtual Networks in a TRILL campus.
3. A traffic bottleneck at the gateway.
This document specifies an optional TRILL distributed gateway solution that resolves these centralized gateway issues.
RFC7961 - Transparent Interconnection of Lots of Links (TRILL): Interface Addresses APPsub-TLV
This document specifies a TRILL (Transparent Interconnection of Lots of Links) IS-IS application sub-TLV that enables the reporting by a TRILL switch of sets of addresses. Each set of addresses reports all of the addresses that designate the same interface (port) and also reports the TRILL switch by which that interface is reachable. For example, a 48-bit MAC (Media Access Control) address, IPv4 address, and IPv6 address can be reported as all corresponding to the same interface reachable by a particular TRILL switch. Such information could be used in some cases to synthesize responses to, or bypass the need for, the Address Resolution Protocol (ARP), the IPv6 Neighbor Discovery (ND) protocol, or the flooding of unknown MAC addresses.
RFC7968 - Transparent Interconnection of Lots of Links (TRILL): Using Data Labels for Tree Selection for Multi-Destination Data
TRILL (Transparent Interconnection of Lots of Links) uses distribution trees to deliver multi-destination frames. Multiple trees can be used by an ingress Routing Bridge (RBridge) for flows, regardless of the VLAN, Fine-Grained Label (FGL), and/or multicast group of the flow. Different ingress RBridges may choose different distribution trees for TRILL Data packets in the same VLAN, FGL, and/or multicast group. To avoid unnecessary link utilization, distribution trees should be pruned based on one or more of the following: VLAN, FGL, or multicast destination address. If any VLAN, FGL, or multicast group can be sent on any tree, for typical fast-path hardware, the amount of pruning information is multiplied by the number of trees, but there is limited hardware capacity for such pruning information.
This document specifies an optional facility to restrict the TRILL Data packets sent on particular distribution trees by VLAN, FGL, and/or multicast groups, thus reducing the total amount of pruning information so that it can more easily be accommodated by fast-path hardware.
RFC7978 - Transparent Interconnection of Lots of Links (TRILL): RBridge Channel Header Extension
The IETF TRILL (Transparent Interconnection of Lots of Links) protocol includes an optional mechanism (specified in RFC 7178) called RBridge Channel for the transmission of typed messages between TRILL switches in the same campus and the transmission of such messages between TRILL switches and end stations on the same link. This document specifies extensions to the RBridge Channel protocol header to support two features as follows: (1) a standard method to tunnel payloads whose type can be indicated by Ethertype through encapsulation in RBridge Channel messages; and (2) a method to support security facilities for RBridge Channel messages. This document updates RFC 7178.
RFC8139 - Transparent Interconnection of Lots of Links (TRILL): Appointed Forwarders
TRILL (Transparent Interconnection of Lots of Links) supports multi-access LAN (Local Area Network) links where a single link can have multiple end stations and TRILL switches attached. Where multiple TRILL switches are attached to a link, native traffic to and from end stations on that link is handled by a subset of those TRILL switches called "Appointed Forwarders" as originally specified in RFC 6325, with the intent that native traffic in each VLAN be handled by at most one TRILL switch. This document clarifies and updates the Appointed Forwarder mechanism. It updates RFCs 6325 and 7177 and obsoletes RFC 6439.
RFC8171 - Transparent Interconnection of Lots of Links (TRILL): Edge Directory Assistance Mechanisms
This document describes mechanisms for providing directory service to TRILL (Transparent Interconnection of Lots of Links) edge switches. The directory information provided can be used in reducing multi-destination traffic, particularly ARP / Neighbor Discovery (ND) and unknown unicast flooding. It can also be used to detect traffic with forged source addresses.
RFC8243 - Alternatives for Multilevel Transparent Interconnection of Lots of Links (TRILL)
Although TRILL is based on IS-IS, which supports multilevel unicast routing, extending TRILL to multiple levels has challenges that are not addressed by the already-existing capabilities of IS-IS. One issue is with the handling of multi-destination packet distribution trees. Other issues are with TRILL switch nicknames. How are such nicknames allocated across a multilevel TRILL network? Do nicknames need to be unique across an entire multilevel TRILL network? Or can they merely be unique within each multilevel area?
This informational document enumerates and examines alternatives based on a number of factors including backward compatibility, simplicity, and scalability; it makes recommendations in some cases.
RFC8249 - Transparent Interconnection of Lots of Links (TRILL): MTU Negotiation
The base IETF TRILL (Transparent Interconnection of Lots of Links) protocol has a TRILL campus-wide MTU feature, specified in RFCs 6325 and 7177, that assures that link-state changes can be successfully flooded throughout the campus while being able to take advantage of a campus-wide capability to support jumbo packets. This document specifies recommended updates to that MTU feature to take advantage, for appropriate link-local packets, of link-local MTUs that exceed the TRILL campus MTU. In addition, it specifies an efficient algorithm for local MTU testing. This document updates RFCs 6325, 7177, and 7780.
RFC8302 - Transparent Interconnection of Lots of Links (TRILL): ARP and Neighbor Discovery (ND) Optimization
This document describes mechanisms to optimize the Address Resolution Protocol (ARP) and Neighbor Discovery (ND) traffic in a Transparent Interconnection of Lots of Links (TRILL) campus. TRILL switches maintain a cache of IP / Media Access Control (MAC) address / Data Label bindings that are learned from ARP/ND requests and responses that pass through them. In many cases, this cache allows an edge Routing Bridge (RBridge) to avoid flooding an ARP/ND request by either responding to it directly or encapsulating it and unicasting it. Such optimization reduces packet flooding over a TRILL campus.
RFC8361 - Transparent Interconnection of Lots of Links (TRILL): Centralized Replication for Active-Active Broadcast, Unknown Unicast, and Multicast (BUM) Traffic
In Transparent Interconnection of Lots of Links (TRILL) active-active access, a Reverse Path Forwarding (RPF) check failure issue may occur when using the pseudo-nickname mechanism specified in RFC 7781. This document describes a solution to resolve this RPF check failure issue through centralized replication. All ingress Routing Bridges (RBridges) send Broadcast, Unknown Unicast, and Multicast (BUM) traffic to a centralized node with unicast TRILL encapsulation. When the centralized node receives the BUM traffic, it decapsulates the packets and forwards them to their destination RBridges using a distribution tree established per the TRILL base protocol (RFC 6325). To avoid RPF check failure on an RBridge sitting between the ingress RBridge and the centralized replication node, some change in the RPF calculation algorithm is required. RPF checks on each RBridge MUST be calculated as if the centralized node was the ingress RBridge, instead of being calculated using the actual ingress RBridge. This document updates RFC 6325.
RFC8377 - Transparent Interconnection of Lots of Links (TRILL): Multi-Topology
This document specifies extensions to the IETF TRILL (Transparent Interconnection of Lots of Links) protocol to support multi-topology routing of unicast and multi-destination traffic based on IS-IS (Intermediate System to Intermediate System) multi-topology specified in RFC 5120. This document updates RFCs 6325 and 7177.
RFC8380 - Directory-Assisted Transparent Interconnection of Lots of Links (TRILL) Encapsulation
This document describes how data center networks can benefit from non-RBridge nodes performing TRILL (Transparent Interconnection of Lots of Links) encapsulation with assistance from a directory service.
RFC8381 - Transparent Interconnection of Lots of Links (TRILL): Vendor-Specific RBridge Channel Protocol
The IETF TRILL (Transparent Interconnection of Lots of Links) protocol is implemented by devices called TRILL switches or RBridges (Routing Bridges). TRILL includes a general mechanism, called an RBridge Channel, for the transmission of typed messages between RBridges in the same campus and between RBridges and end stations on the same link. This document specifies a method to send vendor-specific messages over the RBridge Channel facility.
RFC8383 - Transparent Interconnection of Lots of Links (TRILL): Address Flush Message
The TRILL (Transparent Interconnection of Lots of Links) protocol, by default, learns end station addresses from observing the data plane. In particular, it learns local Media Access Control (MAC) addresses and the edge switch port of attachment from the receipt of local data frames and learns remote MAC addresses and the edge switch port of attachment from the decapsulation of remotely sourced TRILL Data packets.
This document specifies a message by which a TRILL switch can explicitly request other TRILL switches to flush certain MAC reachability learned through the decapsulation of TRILL Data packets. This is a supplement to the TRILL automatic address forgetting (see Section 4.8.3 of RFC 6325) and can assist in achieving more rapid convergence in case of topology or configuration change.
RFC8384 - Transparent Interconnection of Lots of Links (TRILL) Smart Endnodes
This document addresses the problem of the size and freshness of the endnode learning table in edge Routing Bridges (RBridges), by allowing endnodes to volunteer for endnode learning and encapsulation/decapsulation. Such an endnode is known as a "Smart Endnode". Only the attached edge RBridge can distinguish a "Smart Endnode" from a "normal endnode". The Smart Endnode uses the nickname of the attached edge RBridge, so this solution does not consume extra nicknames. The solution also enables endnodes that are Fine-Grained Label (FGL) aware.
RFC8385 - Transparent Interconnection of Lots of Links (TRILL) Transparent Transport over MPLS
This document specifies methods to interconnect multiple TRILL (Transparent Interconnection of Lots of Links) sites with an intervening MPLS network using existing TRILL and VPLS (Virtual Private LAN Service) standards. This document addresses two problems: 1) providing connection between more than two TRILL sites that are separated by an MPLS provider network and 2) providing a single logical virtualized TRILL network for different tenants that are separated by an MPLS provider network.
RFC8397 - Transparent Interconnection of Lots of Links (TRILL) Multilevel Using Unique Nicknames
TRILL (Transparent Interconnection of Lots of Links) routing can be extended to support multiple levels by building on the multilevel feature of IS-IS routing. Depending on how nicknames are managed, there are two primary alternatives to realize TRILL multilevel: the unique nickname approach and the aggregated nickname approach as discussed in RFC 8243. This document specifies a unique nickname approach. This approach gives unique nicknames to all TRILL switches across the multilevel TRILL campus.
RFC8564 - Support of Point-to-Multipoint Bidirectional Forwarding Detection (BFD) in Transparent Interconnection of Lots of Links (TRILL)
Point-to-multipoint (P2MP) Bidirectional Forwarding Detection (BFD) is designed to verify multipoint connectivity. This document specifies the support of P2MP BFD in Transparent Interconnection of Lots of Links (TRILL). Similar to TRILL point-to-point BFD, BFD Control packets in TRILL P2MP BFD are transmitted using RBridge Channel messages. This document updates RFCs 7175 and 7177.
RFC9600 - TRansparent Interconnection of Lots of Links (TRILL): Explicit Congestion Notification (ECN) Support
Explicit Congestion Notification (ECN) allows a forwarding element to notify downstream devices, including the destination, of the onset of congestion without having to drop packets. This can improve network efficiency through better congestion control without packet drops. This document extends ECN to TRansparent Interconnection of Lots of Links (TRILL) switches, including integration with IP ECN, and provides for ECN marking in the TRILL header extension flags word (RFC 7179).