Design Reference

Table Of Contents

encapsulation of customer MAC addresses in backbone MAC addresses greatly improves network

scalability.

No flooding or learning of end-user MACs occurs in the backbone. This SPBM provisioning

significantly improves network robustness, as customer-introduced network loops have no effect on

the backbone infrastructure.

Service provisioning

Provision I-SIDs on a BEB to associate that BEB with a particular service instance. After you map

the customer VLAN or VRF into an I-SID, any BEB that has the same I-SID configured can

participate in the same Layer 2 or Layer 3 VSN. This same simplicity extends to provisioning the

services to run above the SPBM backbone:

• To create a Layer 2 VSN, associate an I-SID number with an edge VLAN.

•

To create a Layer 3 VSN, associate an I-SID number with a VRF and configure the desired IS-

IS IP route redistribution within the newly created Layer 3 VSN.

Note:

No service provisioning is needed on the core BCB SPBM switches. This provides a robust

carrier grade architecture where configuration on the core switches never needs to be updated

when adding new services.

IP multicast over SPBM

Provisioning IP multicast over SPBM is as simple as enabling SPBM multicast on the BEBs. You do

not need to enable IP multicast over SPBM on the BCBs.

For Layer 2 VSN using IP multicast over SPBM, configure Internet Group Management Protocol

(IGMP) snooping on the VLAN that represents the Layer 2 VSN.

For Layer 3 VSNs using IP multicast over SPBM, configure the Layer 3 VSN as a multicast VSN,

and then enable IP multicast over SPBM on each VLAN within the VRF to which IP multicast

senders and receivers attach.

For IP shortcuts using IP multicast over SPBM, enable IP multicast over SPBM on each of the

VLANs within the Global Routing Table (GRT) that need to support IP multicast traffic.