Cisco Cisco Packet Data Interworking Function (PDIF)
System Settings
Configuring ASR 5000 Link Aggregation ▀
ASR 5000 System Administration Guide, StarOS Release 18 ▄
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Table 5. QGLC and XGLC LAG Functionality
Card Type
ASR 5000
LAGID
Ethernet Switch A
Ethernet Switch B
QGLC
Port 1
1
Port 1
----
Port 2
1
Port 2
----
Port 3
1
----
Port 1
XGLC
Slot 1
1
Port 1
----
Slot 2
1
----
Port 1
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 redundancy)
connected to different switches, each card provides a candidate aggregation of bandwidth. Selection by bandwidth
works because the failure of one port causes that card’s bandwidth to be lower, thus causing another card to be selected.
aggregation. If there are several horizontal cards with LAG ports that are all in active mode (no L2 redundancy)
connected to different switches, each card provides a candidate aggregation of bandwidth. Selection by bandwidth
works because the failure of one port causes that card’s bandwidth to be lower, thus causing another card to be selected.
The figure below shows an LAG established across two line card ports without L2 redundancy.
Figure 8.
LAG without L2 Redundancy, Two Ethernet Switches
Multiple Switches with L2 Redundancy
To handle the implementation of Link Aggregation Control Protocol without requiring standby ports to pass LACP
packets, two separate instances of LACP are started on redundant cards. The two LACP instances and port link state are
monitored to determine whether to initiate an auto-switch (including automatic L2 port switch).
packets, two separate instances of LACP are started on redundant cards. The two LACP instances and port link state are
monitored to determine whether to initiate an auto-switch (including automatic L2 port switch).
Two switches can also be connected to odd and even slots of an XGLC in active-active mode without L2 redundancy.
Two LACP instances are started for odd and even slots, and similar monitoring and switching occurs.
Two LACP instances are started for odd and even slots, and similar monitoring and switching occurs.
The figure below shows an LAG established across two line card ports with L2 redundancy.