Preferred Slot - Cisco ASR 5000 Series Administration Manual

Link Aggregation Control
The LAG manager also enters/extends the hold period when an administrator manually switches ports to
trigger a card switch.

Preferred Slot

You can define which card is preferred per LAG group as a preferred slot. When a preferred MIO/UMIO/MIO2
slot is specified, it is selected for the initial timeout period to make the selection of a switch less random.
Port preference is not allowed in this mode.
Auto-Switch Criteria
The following criteria determine the switching of card x to card y to provide better bandwidth while allowing
manual intervention. The evaluation of the criteria occurs outside of the hold period.
Ports are automatically switched from card x to card y when A(y) = 1, at least one port is in aggregated state
on card y, and one of the following conditions is true (in order of precedence):
• L(x) L(y) Less ports with link Up on card x than card y
• S(x) S(y) More ports in Standby state on card x than card y
• W(x) W(y) More ports in Waiting state on card x than card y
• A(x) A(y) Fewer ports in Aggregated state on card x than card y
• Card y is preferred
• Card y is selected.
Link Aggregation Control
One port in an aggregation group is configured as a master so that all traffic (except control traffic) in the
aggregation group logically passes through this port. It is recommended that you configure link-aggregation
on the master port first when enabling LAG, and unconfigure the master port last when disabling LAG.
The following command creates link aggregation group N with port slot#/port# as master. Only one master
port is allowed for a group. N must be in the range of [1–255].
configure
port ethernet slot#/port#
link-aggregation master group N
exit
Important
Use the following command to add a port as member of link aggregation group number N only if the master
port is assigned. Otherwise, it is added to the group when the master port is assigned:
port ethernet slot#/port#
link-aggregation member group N
exit
ASR 5500 System Administration Guide, StarOS Release 21.4
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Link Aggregation Control Protocol (LACP) starts running only when the master port is enabled.
System Settings