User's Manual

Table Of Contents
264
Users Manual of GPL-8000
Fast Ethernet Ring Protection Configuration
27.2.1 Requisites before Configuration
Before configuring MEAPS, please read the following items carefully:
One of important functions of the ring protection protocol is to stop the broadcast storm, so please make
sure that before the ring link is reconnected all ring nodes are configured. If the ring network is connected
in the case that the configuration is not finished, the broadcast storm may easily occur.
Set the ring protection protocol to realize the compatibility of STP. The users are allowed to set “no
spanning-tree”, SSTP, RSTP and MSTP.
After an instance of the ring's node is set, users are forbidden to change the basic information of the node
(excluding the time parameters) unless the current ring’s node is deleted and then reset.
If you run show to browse the configured node and find its state is init, it shows that the node’s
configuration is unfinished and therefore the node cannot be started. In this case, you are required to
change or add basic information to complete the configuration of the node.
The ring protection protocol supports a switch to configure multiple ring networks.
The configuration of the control VLAN of the ring network does not automatically establish the
corresponding systematic VLAN. You need to establish the systematic VLAN manually through global
VLAN configuration command.
The port of each ring can forward the packets from the control VLAN of the ring, while other ports, even in
the Trunk mode, cannot forward the packets from the control VLAN.
By default, Fail-time of the master node is triple longer than Hello-time, so that packet delay is avoided
from shocking the ring protection protocol. After Hello-time is modified, Fail-time need be modified
accordingly.
By default, Pre-Forward-Time of the transit node is triple longer than Hello-time of the master node so that
it is ensured that the master node can detect the recovery of the ring network before the transit port enters
the pre-forwarding state. If Hello-time configured on the master node is longer than Fre-Forward-Time of
the transit node, loopback is easily generated and broadcast storm is then triggered.
Users cannot set Edge Hello Time and Edge Fail Time, and their default values are decided by Hello Time
and Fail Time respectively for their values are 1/3 of Hello Time and Fail Time respectively.
The physical interface, the fast-Ethernet interface, the gigabit-Ethernet interface and the aggregation
interface can all be set to be the ring's interfaces. If link aggregation, 802.1X or port security has been
already configured on a physical interface, the physical interface cannot be set to be a ring’s interface any
more.
This protocol is similar with the original EAPS in functions, but its ring’s topology has more expansibility
and flexibility. Hence, MEAPS and EAPS are partially compatible, and the intersection configuration can
be done on the MEAPS ring and the EAPS ring. But a same physical port cannot be simultaneously set to
support MEAPS and EAPS.