EVPN Flashcards
Q
A
In EVPN, the split horizon problem is solved using a ‘split horizon tag.’
False, it’s the split horizon label.
EVPN uses route type 1.
True
PBB-EVPN uses route type 2.
True
PBB-EVPN requires the split horizon label.
False
What types of BGP routes are used by EVPN-PBB?
2, 3, and 4
What is an EVI?
It is an EVPN instance, similar to a VRF, uses RT.
Describe the operation of mapping interesting traffic to EVI.
On the physical interface, an EFP is created which is mapped to a Bridge domain, and this is mapped to EVI.
What are ES?
Ethernet Segments, associated with customer-facing interfaces. The Ethernet Segment Identifier identifies a customer site that can be connected to more than one PE. The ESI is important for providing redundancy.
BGP routes also signal the MPLS labels associated with MAC addresses and Ethernet segments.
True
EVPN and PBB-EVPN require the signaling and maintenance of pseudowires.
False
EVPN MPLS labels represent Multipoint-to-Point (MP2P) Label Switched Paths (LSPs).
True
EVPN Operation - Ethernet segment reachability: The PE discovers remote ESIs and their corresponding redundancy mode (all-active or single-active). In case of segment failures, PEs withdraw the routes used at this stage to trigger fast convergence by signaling a MAC mass withdrawal on remote PEs.
ESIs, (all-active or single-active)
EVPN Operation - Redundancy Group membership: PEs connected to the same Ethernet segment (multi-homing) automatically discover each other and elect a Designated Forwarder (DF) responsible for forwarding Broadcast, Unknown unicast, and Multicast (BUM) traffic for a given EVI.
Designated Forwarder (DF)
VPN membership: The PE discovers all remote PE members of a given EVI. In the case of a multicast ingress replication model, this information is used to build the PE’s flood list associated with an EVI.
EVI = VRF L2
After route exchange, when a client frame arrives at the PE, it announces EVPN MAC advertisement routes to distribute reachability information in the CORE.
EVPN MAC advertisement
Terminology EVPN PBB - When it comes to PBB-EVPN, there are two types of BDs, the Edge Bridge Domain and the Core Bridge Domain. The Edge Bridge Domain is where the Attachment Circuits (interfaces connected towards customers) are included as part of the BD. This means all the Customer-MAC addresses (C-MAC) are part of this broadcast domain. The Core Bridge Domain mainly contains the B-MAC, which are the MAC addresses of each Provider Edge device (for reachability purposes) within the same MPLS network.
Edge Bridge Domain and Core Bridge Domain
i-SID: Service Instance Identifier, serves the purpose of identifying the service instance. It is best practice to keep the i-SID values unique per customer service instance.
i-SID
The real reason is the flexibility of PBB-EVPN based L2 Services, the way it reduces the BGP MAC advertisement by aggregating the C-MAC via B-MAC addresses (Mapping of Customer MAC addresses to Backbone MAC addresses).
C-MAC via B-MAC
