This document discusses Extreme Fabric Connect, which is based on IEEE 802.1aq Shortest Path Bridging MAC-in-MAC (SPBM). It provides concise overviews of Fabric Connect's architecture, protocols, services, and use cases for campus, metro, and data center fabrics. Key points covered include that Fabric Connect uses IS-IS routing over SPBM encapsulation to provide shortest path routing, multi-pathing, and other benefits for L2 and L3 virtual switching across the network fabric.

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Extreme Fabric Connect
Паливода Александр
opali@muk.ua
Системный инженер МУК

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VistaPoint
Новый

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Fabric Connect

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Fabric Connect in a Single Slide
 Based on IEEE 802.1aq
 Basically a nextgen-ish VLAN
– With an ID coded on 24bit
– Encapsulated in a Mac header (Mac-in-Mac 802.1ah)
 Routed by IS-IS
– Multipaths with no blocked path
– Loop free
– Symmetry & congruence
– Multicast & unicast
– QoS-aware
 Core is transparent
– Provisionning at the Edge only
 Supported on most switches, from Core to Access
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Fabric Connect in a Picture
SPB extended
over WAN
(Fabric Extend)
Wiring Closet
Campus
Distribution
Server Access (TOR)
Hypervisors
Data Centre
Distribution
Branch Core
Internet
DMZ / Internet
SPB Backbone
(Fabric Connect)
Fabric
Attach
BEB
BEB
BEB
BEB
L2 BEBs L2 BEBs
BEB BEB BEB BEB
BEB BEBBEB BEB
BEB
BEB
BCB BCB
BCB BCB
FA Proxies FA Proxies
Fabric Attach
Wireless Access WLAN AP FA Clients

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Fabric Connect
 Fabric Connect is based on SPBM
– Long history with ex-Nortel Networks,
– Strong supporter of PBB (Mac-in-Mac) in the past
– Strong supporter of SPBM nowadays
 Fair to say SPBM implementation by Avaya is the most
complete
– Full IEEE features
– Many proprietary implementations to go beyond
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Fabric Connect
 Fabric Connect is based on SPBM
– IEEE 802.1aq
– IETF RFC 6329
 SPBM simplicity comes from its unique protocol infrastructure
– Compared to multiple protocols stack for traditional networking
 MPLS, VXLAN/BGP, etc.
 Data Plane
– Based on an Ethernet ISID
– « NG VLAN », more scalable and secure
 Control Plane
– Based on IS-IS routing
– IP/IPVPN services uses IP extensions
https://tools.ietf.org/html/draft-unbehagen-spb-ip-ipvpn-00

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Fabric Connect
 Fabric Connect is used for
– Campus
– Metro
– DC Fabric
– DCI
 Fabric Connect benefits
– Service Provisioning at the Edge
– L2 & L3 service virtualization
– Shortest Path & Multi Path
– MAC scaling
– Fast Convergence
– Topology Independant

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SPBM Frame Format
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Fabric Connect
 Dual-Homing support at the Edge
– SMLT any devices supporting LAG
– Extension to SPB 802.1aq

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Fabric Connect
 Fabric Connect relies purely on SPBM for discovery
– IS-IS forms adjacencies to neighbouring nodes,
– Discovers the core network topology,
– Then automatically calculates shortest paths from itself to every
other node in the network
– IS-IS programs forwarding entries in the BVIDs

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Fabric Connect
 Important Properties
– Shortest path based on link metrics with no blocked paths
– Reverse Path Forwarding Check (RPFC) eliminates loops
– Symmetric data path between any two nodes provides closed
OAM system
– Unicast path calculated from every node to every other node
– Ability to calculate service specific multicast delivery trees
– No IP configuration required inside the Fabric
– Network becomes a Virtual Switched Fabric

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Fabric Connect
 L2 Services
– IS-IS calculates the shortest path and
programs the BMAC addresses into the
FDBs
– A VLAN provisioned at the edge of the
fabric is mapped into the Virtual Service
Network using the Service Identifier (I-SID)
– IS-IS advertises all new services and
communities of interest (I-SID information)
to the network and the Forwarding Data
Base is updated with I-SID Service
specific entries

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Fabric Connect
 L2 Service VSN
– Congruent unicast & multicast paths
– Congruent forward & reverse path
 Important Properties
– All traffic types (known, unknown traffic,
broadcast) use same path; no out of order
packets possible
– Traffic A -> B will follow same path as B -> A
– Multicast trees are ROOT-ed at source node
within every service instance and only flood
packets to I-SID service node members
– No MAC learning & flooding in the Core
– Fully QoS aware infrastructure

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Fabric Connect – L3 Service VSN
 A Virtual Routing instance (VRF)
provisioned at the edge of the
fabric is mapped into the Virtual
Service Network using the
Service Identifier (I-SID)
 IS-IS advertises all new services
and communities of interest (I-
SID information) to the network
as well as the VRF IP routes
which are only accepted and
installed on other nodes in the
same I-SID

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Fabric Connect – VRF0 IP Shortcuts
 Global Routing Table (GRT or
VRF0) provisioned at the edge
of the fabric forwards standard
IP packets over IS-IS in the
SPBM core
 IS-IS used to advertise IP route
reachability and IP routes are
installed in GRT/VRF0 IP
routing table with next-hop
shortcut to reach advertising
node

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Fabric Connect – SPB VSN Service Flexibility
 Routing anywhere in the Fabric with L3VSNs (or GRT IP shortcuts)
 Extend L2 VLANs anywhere inside or across the Fabric using L2VSNs

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Fabric Connect – IP Multicast Services
 A multicast stream received at the edge
of the fabric is mapped into a dedicated
multicast Service Identifier (I-SID)
– IGMP at the edge
– IS-IS in the fabric
– No need for PIM or DVMRP complexity
– Can be constrained within a L2 or L3
VSN
 IS-IS advertises the stream to the rest of
the fabric
– The stream is not forwarded until a
receiver requests it and is forwarded
ONLY to those receivers who
requested it

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Fabric Connect – SPB Fabric based Video Surveillance

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Fabric Connect
 Fabric NNI links can be extended
over Ethernet links or over IP
tunnels
 All services can be seamlessly
extended

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Fabric Connect – UNI Types
 UNI Service classification types
– C-VLAN UNI with IP routing interface support
– Switched UNI
– Transparent UNI
– ETREE UNI
 UNI Interface types
– Single port
– MLT/Distributed-MLT/LAG
– Split-MLT/vIST/MC-LAG

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L2VSN – UNI Types: C-VLAN UNI
 UNI is a VLAN
 C-VLAN UNIs can have a routing interface
 VLAN has global significance on the BEB
 VLAN performs L2 switching on local VLAN port members & transports over L2VSN for
remote end-points
 Untagged traffic is assigned to VLAN corresponding to PVID configured on port
 Not supported on DVR-leaf

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L2VSN – UNI Types: Switched UNI
 UNI is a VLAN ID on an ethernet port
 VLAN ID has local significance on the ethernet port
 Same VLAN ID can be re-used on different ports and belong to a different I-SID
 Different VLAN ID on same or different ports can be assigned to same I-SID
– Can do VLAN Mapping on local switch

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L2VSN – UNI Types: Transparent UNI
 UNI is an ethernet port
 Ethernet UNI port is not VLAN tag aware
 Packets with or without a VLAN tag are transported into the
L2VSN

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Data Center Spine-Leaf Fabric
 Scale-out Data Center Fabric
– Distributed Routing Model: routing on the leaf

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Fabric Connect and VXLAN
 VXLAN HW Gateway (7254, 8284, 8404, 8600)
– VXLAN Bridging (VLAN/ISID – VXLAN)
– VXLAN Routing (VLAN/VRF/ISID – VXLAN)
– VXLAN Overlay Fabric
– No Control Plane for VXLAN (static config)
 RIOT support on Trident2-based switches
– Requires to re-circulate the packets
– L3 bandwidth limitation of the (internal) ports used
– 480Gbps bidirectional (240Gbps in / 240Gbps out)
 RIOT support on VSP 8600
– Single-pass RIOT and linerate
– Fabric Connect support planned for End of 2017
– VXLAN GW planned for 1HCY18