Cisco Cisco Packet Data Gateway (PDG)
System Settings
▀ Configuring ASR 5500 Link Aggregation
▄ ASR 5500 System Administration Guide, StarOS Release 18
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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.
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].
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:
Link Aggregation Control Protocol (LACP) starts running only when the master port is enabled.
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:
assigned. Otherwise, it is added to the group when the master port is assigned:
port ethernet slot#/port#
link-aggregation member group N
exit
Important:
The VPN can only bind the master port, and a VLAN can only be created on the master port. A
failure message is generated if you attempt to bind to a link aggregation member port.
Each system that participates in link aggregation has a unique system ID that consists of a two-byte priority (where the
lowest number [0] has the highest priority) and a six-byte MAC address derived from the first port’s MAC address. The
following command sets the system priority used to form the system ID. P is a hex in the range [0x0000..0xFFFF]. The
default is 0x8000.
lowest number [0] has the highest priority) and a six-byte MAC address derived from the first port’s MAC address. The
following command sets the system priority used to form the system ID. P is a hex in the range [0x0000..0xFFFF]. The
default is 0x8000.
card slot#
link-aggregation system-priority P
Ports in a system are assigned keys. The group number maps directly to the key, whereupon only ports with the same
key can be aggregated. Ports on each side of the link use a different aggregation key.
key can be aggregated. Ports on each side of the link use a different aggregation key.
The system ID, port key and port ID of two peers form the Link Aggregation Group Identifier (LAGID). You can
aggregate links having the same LAGID. Systems are often configured initially with each port in its own aggregation
(requiring a separate key per port), or with all ports in the same aggregation (a single key for all ports). Negotiation via
LACP would qualify the actual aggregation.
aggregate links having the same LAGID. Systems are often configured initially with each port in its own aggregation
(requiring a separate key per port), or with all ports in the same aggregation (a single key for all ports). Negotiation via
LACP would qualify the actual aggregation.
Systems exchange information about system ID, port key and port ID with peers across the physical links using LACP.
LACP packets are defined with the Slow Protocol format. Each system sends out its own (“actor”) information and its
last received information about its peer (“partner”) over the physical link.
last received information about its peer (“partner”) over the physical link.