Stack Ports - Cisco 350XG series Administration Manual

Administration: Stack Management

Stack Ports

Stack Ports
Cisco 350XG & 550XG Series 10G Stackable Managed Switches
All ports on the device are network (uplink) ports by default. To connect units, you
must change the types of the ports to be used to connect the devices as stack
ports. These ports are used to transfer data and protocol packets among the units
You must indicate to the system (reserve) which ports you plan to use as stack
ports (in the Stack Management
Stack Port Link Aggregation
When two neighboring units are connected, the stack ports connecting them are
automatically assigned to a stack LAG. This feature enables increasing the stack
bandwidth of the stack port beyond that of a single port.
There can be up to two stack LAGs per unit.
The stack LAG can be composed of between two and up to the maximum number
of stack ports depending on the unit type.
Stack Port States
Stack ports can be in one of the following states:
• Down—Port operational status is down or stack port operational status is
up, but traffic cannot pass on the port.
• Active—Stack port was added to a stack LAG whose stack port
operational status is up and traffic can pass on the port and it is a member
of a stack LAG.
• Standby—Stack port operational status is up and bidirectional traffic can
pass on the port, but the port cannot be added to a stack LAG, and the port
does not transmit traffic. Possible reasons for a port being in standby are:
- Stack ports with different speeds are used to connect a single neighbor.
- One unit is connected to more than two neighboring units.
Physical Constraints for Stack LAGs
The following factors constrain the use of stack LAGs:
• A stack LAG must contain ports of the same speed.
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