Bidirectional Forwarding Detection Over Logical Bundle; Bidirectional Forwarding Detection Over Generic Routing Encapsulation; Bidirectional Forwarding Detection Ipv6 Multihop - Cisco ASR 9000 Series Routing Configuration Manual

Implementing BFD

Bidirectional Forwarding Detection over Logical Bundle

The Bidirectional Forwarding Detection (BFD) over Logical Bundle feature implements and deploys BFD
over bundle interfaces based on RFC 5880. The BFD over Logical Bundle (BLB) feature replaces the BVLAN
feature and resolves certain interoperability issues with other platforms that run BFD over bundle interface
in pure RFC5880 fashion. These platforms include products of other vendors, as well as other Cisco products
running Cisco IOS or Cisco Nexus OS software.
BLB is a multipath (MP) single-hop session. BLB requires limited knowledge of the bundle interfaces on
which the sessions run; this is because BFD treats the bundle as one big pipe. To function, BLB requires only
information about IP addresses, interface types, and caps on bundle interfaces. Information such as list of
bundle members, member states, and configured minimum or maximum bundle links are not required.
BLB is supported on IPv4 address, IPv6 global address, and IPv6 link-local address. The current version of
the software supports a total of 200 sessions (which includes BFD Single hop for physical and logical
sub-interfaces; BFD over Bundle (BoB) and BLB) per line card. The maximum processing capability of BFD
control packets, per line card, has also increased to 7000 pps (packets per second).
ISSU is not supported for BFD over Logical Bundle feature.
Note
BFD over Logical Bundle feature is not supported on Cisco ASR 9000 Series SPA Interface Processor-700.

Bidirectional Forwarding Detection over Generic Routing Encapsulation

Bidirectional Forwarding Detection (BFD) over Generic Routing Encapsulation (GRE) allows link failures
to be detected more rapidly than existing GRE keepalives. BFD switching over GRE links works when the
BFD packets are transmitted from one end point node to another remote end point node. BFD punting over
GRE links works when BFD packets are received at any of the end points.
Generic Routing Encapsulation (GRE) tunneling protocol encapsulates a wide variety of protocol packet types
inside IP tunnels, creating a virtual point-to-point link between two routers at remote points over an IP
internetwork. The GRE enables service providers that do not run MPLS in their Core network to provide VPN
services.
BFD over GRE feature is not supported on Cisco ASR 9000 Series SPA Interface Processor-700.
BFD provides IPv4 single-hop version 1 asynchronous mode over GRE numbered interfaces according to
RFC5880.

Bidirectional Forwarding Detection IPv6 Multihop

Bidirectional Forwarding Detection (BFD) IPv6 Multihop feature enables IPv6 Multihop BFD sessions where
BFD neighbors can be multiple hops away, either physically or logically. More than one path is available to
reach the BFD neighbor. BFD packets are received on a line card that may or may not host the respective
BFD session. The BFD Agent in one line card may need to transmit BFD packets out of an egress interface
on a different line card.
BFD support for IPv6 Multihop is on a par with the BFD IPv4 Multihop. The BFD IPv6 Multihop is supported
on the ASR 9000 Ethernet Line Card and the ASR 9000 Enhanced Ethernet Line Card.
BFD IPv6 Multihop feature is not supported on Cisco ASR 9000 Series SPA Interface Processor-700.
Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide, Release 5.3.x
Bidirectional Forwarding Detection over Logical Bundle
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