Extreme Networks Summit Summit24, Installation And User Manual

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Overview of the EAPS Protocol
Summit24e3 Switch Installation and User Guide 121
Figure 22: EAPS operation
If the ring is complete, the master node logically blocks all data traffic in the transmit and receive
directions on the secondary port to prevent a loop. If the master node detects a break in the ring, it
unblocks its secondary port and allows data traffic to be transmitted and received through it.
Fault Detection and Recovery
EAPS fault detection on a ring is based on a single control VLAN per EAPS domain. This EAPS domain
provides protection to one or more data-carrying VLANs called protected VLANs.
The control VLAN is used only to send and receive EAPS messages; the protected VLANs carry the
actual data traffic. As long as the ring is complete, the EAPS master node blocks the protected VLANs
from accessing its secondary port.
NOTE
The control VLAN is not blocked. Messages sent on the control VLAN must be allowed into the switch
for the master node to determine whether the ring is complete.
EW_071
Direction of
health-check
message
Master
node
Secondary port
is logically blocked
S 4
S 5
S 6
S 3
S 2
S 1
S P