Lag And Master Port; Lag And Port Redundancy; Lag And Multiple Switches; Multiple Switches Without L2 Redundancy - Cisco ASR 5000 Administration Manual

System Settings
• Ports from horizontal QGLCs where ports could be from different cards, while some cards could be in
Important

LAG and Master Port

Logical port configurations (VLAN and binding) are defined in the master port of the LAG. If the master port
is removed because of a card removal/failure, another member port becomes the master port (resulting in VPN
binding change and outage), unless there is a redundant master port available.

LAG and Port Redundancy

A LAG supports redundant ports, either top-down on the QGLC (vertical link aggregation) or horizontal link
aggregation on the XGLC, when only one port is active in the pair. By default, active ports in a LAG can be
on any XGLC or QGLC, but optionally, all ports in a LAG can be auto-switched to another card when certain
active port counts or bandwidth thresholds are crossed.

LAG and Multiple Switches

This feature connects ports on XGLCs or QGLCs to ports on Ethernet switches. A port failure/switch forces
all ports in a LAG to switch to another XGLC or QGLC when a specified threshold is crossed. This works in
a way similar to the auto-switch feature for port redundancy. LACP runs between the ASR 5000 and the
Ethernet switch, exchanging relevant pieces on information, such as health status.
The following table summarizes typical LAG functionality with QGLCs or XGLCs.
Table 4: QGLC and XGLC LAG Functionality
Card Type ASR 5000
QGLC Port 1
Port 2
Port 3
XGLC Slot 1
Slot 2

Multiple Switches without L2 Redundancy

If one LAG is connected to different peers, by default, the implementation selects the higher bandwidth peer
to form aggregation. If there are several horizontal cards with LAG ports that are all in active mode (no L2
L2 (side-by-side) redundancy.
LAG cannot be configured when XGLCs have been configured for side-by-side redundancy. A failure
message appears on the CLI when such an attempt is made.
LAGID
1
1
1
1
1
Ethernet Switch A
Port 1
Port 2
----
Port 1
----
ASR 5000 System Administration Guide, StarOS Release 21.1
LAG and Master Port
Ethernet Switch B
----
----
Port 1
----
Port 1
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