H3C S9500E Series Configuration Manual page 16

Technology Introduction
Smart Link is a feature developed to address the slow convergence
issue with STP. It provides link redundancy as well as fast
Smart Link
convergence in a dual uplink network, allowing the backup link to
take over quickly when the primary link fails.
As a Layer 2 management protocol, MSTP eliminates Layer 2 loops
MSTP by selectively blocking redundant links in a network, while allowing
for link redundancy.
RRPP is a link layer protocol designed for Ethernet rings. RRPP can
prevent broadcast storms caused by data loops when an Ethernet
RRPP ring is healthy, and rapidly restore the communication paths
between the nodes in the event that a link on the ring is
disconnected.
Fast Reroute (FRR) provides a quick per-link or per-node protection
on an LSP. In this approach, once a link or node fails on a path,
FRR comes up to reroute the path to a new link or node to bypass
FRR
the failed link or node. This can happen as fast as 50 milliseconds,
minimizing data loss. Protocols such as RIP, OSPF, IS-IS, static
routing, and RSVP-TE support this technology.
GR ensures the continuity of packet forwarding when a protocol
such as BGP, IS-IS, OSPF, LDP, or RSVP-TE restarts, or during an
GR
active/standby switchover process. GR needs other devices to
implement routing information backup and recovery.
NSR is a new feature used to ensure non-stop data transmission
during an active/standby switchover. NSR backs up IP/MPLS
forwarding information from the AMB to the SMB. Upon an
NSR
active/standby switchover, NSR can complete link state recovery
and route re-generation without requiring the cooperation of other
devices. IS-IS supports this feature.
VRRP is an error-tolerant protocol, which provides highly reliable
VRRP default links on multicast and broadcast LANs such as Ethernet,
avoiding network interruption due to failure of a single link.
A single availability technology cannot solve all problems. Therefore, a combination of
availability technologies, chosen on the basis of detailed analysis of network environments and
user requirements, should be used to enhance network availability. For example, access-layer
devices should be connected to distribution-layer devices over redundant links, and core-layer
devices should be fully meshed. Also, network availability should be considered during planning
prior to building a network.
16
Reference
High Availability
Configuration
Guide/Smart Link
Configuration
Layer 2 – LAN
Switching
Configuration
Guide/MSTP
Configuration
High Availability
Configuration
Guide/RRPP
Configuration
Layer 3 – IP Routing
Configuration Guide,
MPLS Configuration
Guide/Configuration
Guide of the
corresponding
protocols
High Availability
Configuration
Guide/GR Overview
Layer 3 – IP Routing
Configuration
Guide/IS-IS
Configuration
High Availability
Configuration
Guide/VRRP
Configuration