Figure 1: Egress Traffic Flow With Local Link Bias; Figure 2: Egress Traffic Flow Without Local Link Bias - Juniper EX2200 Hardware Manual

Chapter 1: Interfaces Overview
VCF using a different member link in the LAG bundle. The traffic flow of traffic exiting a
Virtual Chassis or VCF over a LAG bundle when local link bias is enabled is illustrated in
Figure 1 on page 17.

Figure 1: Egress Traffic Flow with Local Link Bias

When local link bias is disabled, egress traffic exiting a Virtual Chassis or VCF on a LAG
bundle can be forwarded out of any member link in the LAG bundle. Traffic forwarding
decisions are made by an internal algorithm that attempts to load-balance traffic between
the member links in the bundle. VCP bandwidth is frequently consumed by egress traffic
when local link bias is disabled because the egress traffic traverses the VCPs to reach
the destination egress member link in the LAG bundle. The traffic flow of traffic exiting
a Virtual Chassis or VCF over a LAG bundle when local link bias is disabled is illustrated
in Figure 2 on page 17.

Figure 2: Egress Traffic Flow without Local Link Bias

Local link bias is configured in a LAG bundle. A Virtual Chassis or VCF that has multiple
LAG bundles can contain bundles that have and have not enabled local link bias. Local
link bias only impacts the forwarding of unicast traffic exiting a Virtual Chassis or VCF;
ingress traffic handling is not impacted by the local link bias setting. Egress multicast,
unknown unicast, and broadcast traffic exiting a Virtual Chassis or VCF over a LAG bundle
is not impacted by the local link bias setting and is always load-balanced among the
member links. Local link bias is disabled, by default.
You should enable local link bias if you want to conserve VCP bandwidth by always
forwarding egress unicast traffic on a LAG bundle out of a local link. You should not
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