Network Virtualization using Extreme Fabric Connect

Table Of Contents
Network Virtualization Using Extreme Fabric Connect
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The same picture illustrates how at the same time some other fabric-wide L2 VSN segments (e.g., for Guest
WLAN users where the default gateway is implemented by a captive portal in the data center and thus no
IP interface is needed in the SPB fabric) can also be extended to the same wiring closet switches in the
same exact manner. Note that in this case there need not be a platform VLAN defined on the distribution
BEB node as Fabric Attach uses Switched UNI functionality, which can directly map the L2 connection into
the desired fabric L2 VSN without any additional provisioning required on the BEB FA Server.
Note
For a Fabric Attach VLAN:I-SID binding, the only reason to have a platform VLAN defined
on the FA Server BEB is if either an IP interface is required on the BEB to act as default
gateway for the segment and/or if there is a need to activate SPB Multicast on that
segment.
Where the distribution layer nodes connect to Extreme Networks Fabric Attach access switches, the BEBs
can be aggregated into an SMLT cluster (Multi-chassis Link Aggregation Group MLAG) in such a way that
the Layer 2 access switches can be connected with simple MLT (or LACP or EtherChannel) link aggregation.
This allows user VLANs to be redundantly q-tagged to any number of access switches (on as many SMLT
links) with all uplinks actively used for traffic forwarding and no Spanning Tree required. This is illustrated in
Figure 82.
Clearly any VSN service terminated on one of the SMLT BEBs will also need terminating on the IST (or
Virtual-IST) peer BEB as well. Hence, for an L3 VSN, both SMLT BEBs will need to have a VRF configured
and the same user VLANs associated to that VRF. For gateway redundancy within those VRF VLANs, either
standards VRRP (with Extreme Networks VRRP-Backup-Master extensions) or Extreme’s RSMLT-Edge
functionality or even DVR can be leveraged. If the SMLT attached device is Fabric Attach capable there is
no need to manage what VLANs are assigned to which SMLT links as the FA Client-Proxy device will
automatically provision these based on their end-point provisioning or via RADIUS authentication of the
connected devices.
Figure 82 Distribution BEB with SMLT Clustering