Specifications

ALAXALA Ring Configuration Guide (Edition 1)

(5)

The mode and parameters must be considered when both Ring Protocol and link aggregation are used.

When you use the link aggregation on the port specified as a ring port, note the following:

(a) We recommend that you use the static link aggregation mode.

The link aggregation has two modes, LACP and static, but we recommend that you use static mode, based on

the following reasons:

- Fallback time superiority when a line failure occurs

(In general, compared to LACP mode, which detects unreachable LACPDUs, static mode provides shorter

communication down time when a line failure occurs or is resolved because static mode directly monitors the

link-down state to detect a failure. This difference also affects the switching time by the Ring Protocol because of the

reason following in (b).)

- Direct connection between devices, which is generally used in a local area network

(If devices are directly connected, you can detect a line failure by simply checking for down links on the

devices.)

These are the reasons we recommend you to use static mode.

Also, we recommend that you set the link debounce time for an Ethernet port to the smallest possible value as

long as there is no particular problem (with line quality, for example).

(b) The parameters for the ring must be set to longer values than the fallback/switching time of the link

aggregation.

If the failure monitoring time of the master node for the Ring Protocol is shorter than the time required for the

fallback or switching operation to complete through the link aggregation, the master node mistakenly detects a

ring failure and switches the path in the ring.

As a result, a loop might occur.

More specifically, for the health-check holdtime in Ring Protocol setting, at least the following two criteria

must be satisfied:

i) health-check holdtime > health-check interval

ii) health-check holdtime > link debounce time + 1200 (for the SFP port)

health-check holdtime > link debounce time + 1500 (for the UTP port)

For details on the configuration, see 5.2 Parameter recommendations for chassis- and box-type switch mixed

networks.

(6)

A ring containing both chassis- and box-type devices must use the parameters for the box-type devices.

In this configuration, AX6300S and AX2430S series switches are used for the core and access switches,

respectively, in each building. With a ring that consists of the chassis-type and box-type models, parameter

settings for box-type devices must be used for both device types.

The backbone ring in this configuration is the monitoring ring of the multi-ring with shared links (O-shaped

ring). In one ring of such a multi-ring, parameter settings for chassis-type devices can be used if all the nodes in

the ring are chassis-type devices.