Configuration Guide

©2021 Extreme Networks, Inc. All rights reserved
October 2021
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14. SPB over L2/L3 networks
14.1 Supported Networks
WithoutFabricExtend WithFabricExtend
Ethernet Direct Cable
4
MPLS / Pseudo-Wire / E-Line (L2)
1
Point-to-Point Ethernet L2 service
4
MPLS VPLS or PBB ELAN (L3 over L2)
2
Q-in-Q Tagged Management Services
4
MPLS IP-VPN
CWDM/DWDM Optical Networks
4
Campus L3 network
1
MPLS VPLS
1
MPLS Pseudo-Wire
3
MPLS IP-VPN via a GRE router
1
At minimum, 1544 byte packets must be supported for the additional 22 byte packet overhead for SPB frame
2
The customer payload must support 1544 byte packets
3
Where an SPB NNI interface is connected to a router that can encapsulate the two B-VLANs into GRE tunnel
4
At minimum, 1594 bytes packets must be supported for the additional SPB and VXLAN overhead if the VSP8000 is
used as it does not support fragmentation. The VSP4000 with ONA is required for fragmentation for networks that do
not support jumbo frames
Without Fabric Extend
The current IEEE 802.1aq SPBM implementations require that all SPBM nodes to form adjacencies over
point-to-point links. Point-to-multipoint and broadcast networks cannot be used to establish SPBM
adjacencies. Any network to be used for an SPBM transport must be capable of transparently supporting
SPBM point-to-point adjacencies with multiple 802.1Q VLANs for each adjacency. Note that Extreme
presently supports two VLANs referred to as Backbone VLANs, hence, the backbone network needs to
support 2 VLANs to natively transport SPBM across the network in addition to forward an untagged default
VLAN for ISIS traffic. Any point-to-point link used to transport SPBM must be capable of supporting at
minimum 1544 byte packets as SPBM adds an additional 22 bytes overhead.
If SPBM is to be transported across an IP network such as a private campus network or MPLS IP-VPN
service, this can be accomplished in a couple of methods. A router can be used between an SPBM node
and the IP network using GRE encapsulation providing end-to-end SPBM support. The router must have
the capability of GRE encapsulating the two SPBM backbone VLANs and supporting fragmentation. The
limitation here is a separate router is required for each SPBM point-to-point link unless it has the capability
of supporting the same two B-VLAN ID’s on multiple ports. Another method could be if the router supported
Pseudowire Switching, but, typically this is supported across an MPLS access network.
Another method is to redistribute ISIS into another protocol such as OSPF, BGP, Static, or RIP depending
on the protocol used in the external network. The disadvantage of this method is you lose end- to-end
SPBM plus you need to route policies to avoid routing loops if there are multiple redistribution points.
With Fabric Extend
Extreme’s Fabric Extend solution allows extension of Fabric Connect (SPBm) over third party transport
networks. It tunnels SPBM traffic over a VXLAN header allowing for end-to-end SPBM networking over