11
T
RUNKS
You can configure a system to aggregate multiple network links into a
single
trunk
. With trunking you can create high-speed point-to-point or
multipoint connections without changing or replacing existing cabling. In
addition, trunking provides automatic point-to-point redundancy
between two devices. Redundant links normally have one link disabled by
Spanning Tree (to prevent looping); trunking utilizes both links.
This chapter provides guidelines and other key information about how to
configure trunking in your system.
The system treats trunked bridge ports in the same way that it treats
normal individual bridge ports. Also, all higher-level network functions —
including Spanning Tree algorithms, virtual LANs (VLANs), and Simple
Network Management Protocol (SNMP) management — do not
distinguish a trunk from any other network port. Unlike for any other
network port, the system automatically distributes traffic across the ports
that are associated with a trunk. If any of the trunk’s ports go down or
up, the system automatically redistributes traffic across the new
arrangement of operational ports.
For more trunking information, see the
Implementation Guide
for your
system.
Trunks can work with MultiPoint Link Aggregation (MPLA). MPLA is a
feature for the CoreBuilder
®
9400 that increases the capacity and
availability of campus LAN cores without using complex, meshed router
networks. Functioning at Layer 2, MPLA provides both dual-homed link
resiliency and automatic load sharing over point-to-multipoint backbone
connections. MPLA increases network availability using scalable Gigabit
Ethernet connections among multiple campus switches. For more
information about MPLA and trunking, see the
CoreBuilder 9400
Implementation Guide
.
