Juniper JUNOS OS 10.4 - RELEASE NOTES Release Note page 11

Copyright © 2010, Juniper Networks, Inc.
New Features in Junos OS Release 10.4 for M Series, MX Series, and T Series Routers
user-defined VLAN ID and VLAN mask combination and steers the packet accordingly.
Modifying the forwarding mode config reboots the PIC.
VLAN steering overview:
In VLAN steering mode, the SA multicast bit is not used for packet steering.
In SA multicast bit steering mode, VLAN ID and VLAN mask configuration is not used
for packet steering.
Configuration of packet forwarding mode and VLAN steering mode uses CLI
commands that result in a PIC reboot.
There are three tag types for ingress packets:
Untagged ingress packet–The packet is sent to PFE1.
Ingress packet with one VLAN–The packet forwards based on the VLAN ID.
Ingress packet with two VLANs–The packet forwards based on the outer VLAN
ID.
VLAN rules describe how the router forwards packets. For VLAN steering, you must
use one of the two rules available in the CLI:
Odd-even rule–Odd number VLAN IDs go to PFE1; even number VLAN IDs go to
PFE0.
High-low rule–1 through 2047 VLAN IDs go to PFE0; 2048 through 4096 VLAN
IDs go to PFE1.
When configured in VLAN steering mode, the PIC can be configured in two physical
interface mode or in aggregated Ethernet (AE) mode:
Two physical interface mode–When the PIC is in two physical interface mode, it
creates physical interfaces et-x/0/0:0 and et-x/0/0:1. Each physical interface can
configure its own logical interface and VLAN. CLI enforces the following restrictions
on commit:
The VLAN ID configuration must comply with the selected VLAN rule.
The previous restriction implies that the same VLAN ID cannot be configured
on both physical interfaces.
AE mode–In AE mode, the two physical interfaces on the same PIC are aggregated
into one AE physical interface. PIC egress traffic is based on the AE internal hash
algorithm. PIC ingress traffic steering is based on the customized VLAN ID rule. CLI
enforces the following restrictions on commit:
The PIC AE working in VLAN steering mode includes both links of this PIC, and
only the links of this PIC.
The PIC AE working in SA multicast steering mode can include more than one
PIC to achieve more than 100-gigabit capacity.
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