Link aggregation means aggregating several
ports together to implement the outgoing/incoming load sharing among the member
ports and to enhance the connection reliability.
In terms of load sharing, link aggregation
may be load-sharing aggregation and non-load-sharing aggregation.
Currently, the S3100-SI
series only supports manually-configured aggregation groups.
For the member ports in an aggregation
group, their basic configuration must be the same. The basic configuration
includes STP, QoS, VLAN, port attributes and other associated settings.
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STP configuration, including STP status (enabled
or disabled), link attribute (point-to-point or not), STP priority, maximum
transmission speed, loop prevention status, root protection status, edge port
or not.
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QoS configuration, including traffic limiting,
priority marking, default 802.1p priority, bandwidth assurance, congestion
avoidance, traffic redirection, traffic statistics, and so on.
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VLAN configuration, including permitted VLANs,
and default VLAN ID.
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Port attribute configuration, including port
rate, duplex mode, and link type (Trunk, Hybrid or Access).
The S3100-SI series supports up to three load-sharing
aggregation groups, with two FE (Fast Ethernet) groups and one GE (Gigabit
Ethernet) group.
Caution:
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An FE port and a GE port cannot be put into the
same aggregation group.
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Each FE aggregation group can have up to eight
FE ports in selected state, and each GE aggregation group can have up to two GE
ports in selected state.
I. Introduction to manual
aggregation
Manual aggregation requires manual
configuration of aggregation groups and prohibits the automatic adding and
deleting of member ports by the system. When an aggregation group contains only
one port, you cannot remove the port unless you remove the whole aggregation
group.
II. Port status in manual
aggregation group
In a manual aggregation group, the ports
may be in selected or unselected state. The selected ports can transceive user
service packets, but the unselected ports cannot.
The selected port with the minimum port
number serves as the master port of the group, and other selected ports serve as
member ports of the group.
In a manual aggregation group, the system
sets the ports to selected or unselected state by using these rules:
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The system sets the port with the highest
priority to selected state, and others to unselected state. The priorities of
the ports descend in the following order: full duplex/high speed, full
duplex/low speed, half duplex/high speed, half duplex/low speed.
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The system sets the ports unable to aggregate
with the master port (due to some hardware limit, for example, there are already
eight FE ports in selected state) to unselected state.
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The system sets the ports with port attribute
configuration different from that of the master port to unselected state.
In terms of load sharing, link aggregation can
be one of the two types: load-sharing aggregation and non-load-sharing
aggregation.
In general, the system only provides
limited load-sharing aggregation resources (currently three load-sharing
aggregation groups can be created at most), so the system needs to reasonably
allocate the resources among aggregation groups of different types.
The system always allocates hardware
aggregation resources to the aggregation groups with higher priorities. When
load-sharing aggregation resources are used up for existing aggregation groups,
newly-created aggregation groups will be non-load-sharing ones.
The priorities of aggregation groups for
allocating load-sharing aggregation resources are as follows:
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An aggregation group containing special ports
which require hardware aggregation resources has higher priority than any
aggregation group containing no special port.
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For two aggregation groups of the same kind
(both contain special ports, or both contain no special port), the one that might
gain higher speed if resources were allocated to it has higher priority than
the other one. If the two groups can gain the same speed, the one with smaller
master port number has higher priority than the other one.
When an aggregation group of higher priority
appears, the aggregation groups of lower priorities release their hardware
resources. For single-port aggregation groups, if they can transceive packets
normally without occupying aggregation resources, they shall not occupy the hardware
aggregation resources.
Caution:
A load-sharing
aggregation group contains at least two selected ports, but a non-load-sharing
aggregation group can only have one selected port, while others are unselected ports.
Table 1-1 Configure a manual aggregation group
|
Operation
|
Command
|
Description
|
|
Enter system view
|
system-view
|
—
|
|
Create an aggregation group
|
link-aggregation group agg-id mode manual
|
Required
|
|
Set a description for the aggregation
group
|
link-aggregation group agg-id description agg-name
|
Optional
By default, an aggregation group has no
description.
|
|
Enter Ethernet port view
|
interface interface-type interface-num
|
—
|
|
Add the Ethernet port to the aggregation
group
|
port
link-aggregation group agg-id
|
Required
|
When adding an Ethernet port to an
aggregation group, note that:
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You cannot add the following types of ports into
an aggregation group: mirroring port, port with static MAC address configured,
port with static ARP configured, port with 802.1x enabled.
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When an aggregation group contains only one
port, you cannot remove the port unless you remove the whole aggregation group.
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If you add more than four ports to an
aggregation group, load sharing is implemented on the four ports with smaller
port numbers, and the rest ports serve as link backups.
After the above configuration, execute the display
commands in any view to display the running of the link aggregation
configuration and verify your configuration.
Table 1-2 Display and debug link aggregation
|
Operation
|
Command
|
|
Display summary information of all
aggregation groups
|
display link-aggregation summary
|
|
Display detailed information of a
specific aggregation group or all groups
|
display link-aggregation verbose [ agg-id ]
|
|
Display
detailed link aggregation information about specified port(s)
|
display
link-aggregation interface interface-type
interface-num [ to interface-type
interface-num ]
|
I. Network requirements
Switch A connects to Switch B with three
aggregation ports GigabitEthernet1/0/1 to GigabitEthernet1/0/3, so that
incoming/outgoing load can be shared among the member ports.
II. Network diagram
Figure 1-1 Network
diagram for link aggregation configuration
III. Configuration procedure
The following only
lists the configuration for Switch A; configure Switch B in the similar way.
# Create manual aggregation group 1.
[H3C] link-aggregation group 1 mode
manual
# Add the Ethernet ports Ethernet1/0/1
through Ethernet1/0/3 to aggregation group 1.
[H3C] interface ethernet1/0/1
[H3C-Ethernet1/0/1] port
link-aggregation group 1
[H3C-Ethernet1/0/1] interface
ethernet1/0/2
[H3C-Ethernet1/0/2] port
link-aggregation group 1
[H3C-Ethernet1/0/2] interface
ethernet1/0/3
[H3C-Ethernet1/0/3] port
link-aggregation group 1
