Smlt Full-Mesh Recommendations With Ospf; Routed Smlt - Avaya 8800 Planning And Engineering

Figure 25: SMLT scaling
For more information about the SMLT triangle, square, and full-mesh designs, see Avaya
Ethernet Routing Switch 8800/8600 Configuration — Link Aggregation, MLT, and SMLT,
NN46205-518.
For more information about SMLT, see the Internet Draft draft-lapuh-network-smlt-06.txt
available at www.ietf.org.

SMLT full-mesh recommendations with OSPF

In a full-mesh SMLT configuration between two clusters running OSPF (typically an RSMLT
configuration), Avaya recommends that you place the MLT ports that form the square leg of
the mesh (rather than the cross connect) on lower numbered slots/ports. This configuration is
recommended because CP-generated traffic is always sent out on the lower numbered MLT
ports when active. This configuration keeps some OSPF adjacencies up in case the IST on
one cluster fails. Without such a configuration, a booted switch in the scenario where the IST is
also down can lose complete OSPF adjacency to both switches in the other cluster and
therefore become isolated.

Routed SMLT

In many cases, core network convergence time depends on the length of time a routing protocol
requires to successfully converge. Depending on the specific routing protocol, this
convergence time can cause network interruptions ranging from seconds to minutes.
Routed Split MultiLink Trunking (RSMLT) allows rapid failover for core topologies by providing
an active-active router concept to core SMLT networks. RSMLT is supported on SMLT
triangles, squares, and SMLT full-mesh topologies that have routing enabled on the core
Planning and Engineering — Network Design
Network redundancy
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