Smlt Versus Stp - Avaya 8600 Configuration Manual

This is accomplished by implementing a method that allows two aggregation switches to
appear as a single device to edge switches, which dual-home to the aggregation switches.
The aggregation switches interconnect using an interswitch trunk, which allows them to
exchange addressing and state information (permitting rapid fault detection and forwarding
path modification). SMLT is designed for Layer 2 network connectivity, but can be configured
in Layer 3 networks by working with VRRP or RSMLT Layer 2 edge.
For more information about SMLT configuration, see Technical Configuration Guide for Switch
Clustering using Split-Multilink Trunking (SMLT), NN48500-518 and SMLT and RSMLT
Technical Configuration Guide. You can find the technical configuration guides at
www.avaya.com/support
SMLT advantages
SMLT eliminates all single points of failure and creates multiple paths from all user access
switches to the network core. In case of failure, SMLT recovers as quickly as possible using
all capacity. SMLT provides a transparent and interoperable solution that requires no
modification on the part of the majority of existing user access devices.
SMLT improves the reliability of Layer 2 networks that operate between user access switches
and the network center aggregation switch by providing:
• load sharing among all links
• fast failover in case of link failures
• elimination of single point of failure
• fast recovery in case of nodal failure
• transparent and interoperable solutions
• removal of STP convergence issues

SMLT versus STP

Networks designed to have user access switches dual-home to two aggregation switches, and
have VLANs spanning two or more user access switches, experience the following design
constraints:
• No load sharing exists over redundant links
• Network convergence is slow in case of failure
With the introduction of SMLT, all dual-home Layer 2 frame-switched network devices with dual
homes are no longer dependent on the STP for loop detection. A properly designed SMLT
network inherently does not have any logical loops.
SMLT solves the spanning tree problem by combining two aggregation switches into one
logical MLT entity, thus making it transparent to any type of edge switch. In the process, it
provides quick convergence, while load sharing across all available trunks.
Configuration — Link Aggregation, MLT, and SMLT
with the rest of the ERS 8800/8600 documentation.
Split MultiLink Trunking
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