Planning The Cable Connection Scheme - H3C S9820-8C-SAN Installation Manual

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If an M-LAG system is attached to a large number of servers by using non-M-LAG interfaces,
take the size of the traffic sent among those servers into account when you determine the
bandwidth of the peer link.
Keepalive link
The M-LAG member devices exchange keepalive packets over the keepalive link to detect
multi-active collisions when the peer link is down.
As a best practice, establish a dedicated direct link between two M-LAG member devices as a
keepalive link. Do not use the keepalive link for any other purposes. Make sure the M-LAG member
devices have Layer 2 and Layer 3 connectivity to each other over the keepalive link.
You can use management Ethernet interfaces, Layer 3 Ethernet interfaces, Layer 3 aggregate
interfaces, or interfaces with a VPN instance bound to set up the keepalive link.
As a best practice, do not use VLAN interfaces for keepalive link setup. If you have to use VLAN
interfaces, remove the peer-link interfaces from the related VLANs to avoid loops.
Do not use the same module to provide interfaces for setting up the keepalive link and peer link.

Planning the cable connection scheme

Select cables or transceiver modules and optical fibers matching the rate of physical ports of the
peer link and the keepalive link for connection.
Cables are short but with high performance and stability, suitable for short-distance connections in
the equipment room. Transceiver modules and optical fibers can be combined flexibly and is suitable
for longer distance connections.
For information about the transceiver modules and cables supported by the switch, see H3C
S9820-64H & S9820-8C & S9820-8C-SAN Ethernet Switches Transceiver Module Compatibility
Matrixes.
This following section describes several cable connection schemes that use QSFP28 cables and
QSFP28 transceiver modules and optical fibers.
NOTE:
The physical port locations in the following figures are for illustration only.
Connecting the member switches in one rack
If two M-LAG member devices are installed in the same rack, use the following connection method to
connect them as a best practice.
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