Avaya 8800 Planning And Engineering, Network Design page 79

Avaya also recommends that you use low slot number ports for the IST, for example ports 1/1 and
2/1, because the low number slots boot up first.
Avaya recommends that you use an independent Virtual Local Area Network (VLAN) for the IST
peer session. To avoid the dropping of IST control traffic, Avaya recommends that you use a
nonblocking port for the IST—for example, any R series module Gigabit Ethernet port.
Avaya recommends that an interswitch multilink trunk contain at least two physical ports, although
this is not a requirement.
Avaya recommends that CP-Limit be disabled on all physical ports that are members of an IST
multilink trunk. Disabling CP-Limit on IST MLT ports forces another, less-critical port to be disabled if
the defined CP-Limit is exceeded. By doing this, you preserve network stability if a protection
condition arises. Although it is likely that one SMLT MLT port (riser) is disabled in such a condition,
traffic continues to flow through the remaining SMLT ports.
IPv4 IST with IPv6 RSMLT
Avaya Ethernet Routing Switch 8800/8600 supports IPv6 RSMLT. However, messaging between
IST peers is supported over IPv4 only.
Dual MLTs in SMLT
Dual MLTs in SMLT designs are supported, as long as only one is configured as an IST MLT (the
system does not allow misconfiguration), and as long as any use of any form of spanning tree, and
the VLANs/ports associated with this form of spanning tree, remain solely on the non-IST MLT;
there can be no association or interaction with the IST MLT.
SMLT and client/server applications
Do not use unbalanced client-server configuration, where core switches have directly-connected
servers or clients. This is not recommended because a loss of one of the IST pair switches causes
connectivity to the server to be lost.
SMLT ID recommendations
SMLT links on both aggregation switches share an SMLT link ID called SmltId. The SmltId identifies
all members of a split multilink trunk group. Therefore, you must terminate both sides of each SMLT
having the same SmltId at the same SMLT client switch. For the exceptions to this rule, see
22: SMLT square configuration
page 85.
The SMLT IDs can be, but are not required to be, identical to the MLT IDs. SmltId ranges are:
• 1 to 128 for MLT-based SMLTs
• 1 to 512 for SLTs
Important:
Avaya recommends to use SLT IDs of 129 to 512 and that you reserve the lower number
IDs of 1 to 128 for SMLT only.
June 2016
on page 85 and Figure 23: SMLT full-mesh configuration
Planning and Engineering — Network Design
Comments on this document? infodev@avaya.com
Network redundancy
Figure
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