Specifications

Overview of the EAPS Protocol
ExtremeWare XOS 11.0 Concepts Guide 177
Figure 11: 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.
Fast Convergence
The Fast Covergence mode allows EAPS to converge more rapidly. In EAPS Fast Convergence mode,
the link filters on EAPS ring ports are turned off. In this case, an instant notification is sent to the EAPS
process if a port’s state transitions from up to down or vice-versa.
You configure Fast Convergence for the entire switch, not by EAPS domain.
EAPS Terms
Table 34 describes terms associated with EAPS.
Table 34: EAPS terms
Term Description
EAPS domain A domain consists of a series of switches, or nodes, that comprise a single ring in a
network. An EAPS domain consists of a master node, transit nodes, and on the
master node, one primary port and one secondary port. EAPS operates by declaring
an EAPS domain on a single ring.
Fast Convergence A process that allows EAPS to converge in less than 50 milliseconds; configure for
the entire switch, not by EAPS domain.
master node A switch, or node, that is designated the master in an EAPS domain ring. The
master node blocks its secondary port for all non-control traffic belonging to this
EAPS domain, thereby avoiding a loop in the ring.
transit node A switch, or node, that is not designated a master in an EAPS domain ring.
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
SP