Each
convergence
group
supports
up
to
eight
ports
.
Port
with
the
following
cases
can
not
be
added
to
an
convergence
group
:
(
1
)
Port with
802
.
1X
function;
(
2
)
The
mirror
port;
(
3
)
Port with
MAC
address
binding
.
26
Instruction
Figure
4
-
5 Trunk
link
STP
contains
two
meanings
,
narrow
meaning
of
STP
is
defined
in
IEEE
802
.
1D
,
board
meaning
of
STP
includs
IEEE
802
.
1D
defined
STP
and
various
enhanced
spanning
tree
protocol
produced
on
the
basis
of
STP
(
such
as
RSTP
protocol
).
In
the
same
convergence
group
,
the
port
speed
,
duplex
mode
,
and
basic
configuration
must
be
consistent
.
STP
consistent
configuration
,
including
STP
ports
on
/
off
,
STP
priority
,
STP
cost
,
whether
to
open
loop
guard
and
root
guard
,
or
edge
ports
.
QoS
configuration
is
consistent
.
VLAN
consistent
configuration
,
including
permitted
VLAN
,
the
default
port
of
VLAN
ID
.
Link
type
on
the
ports
is
consistent
.
4. .2
4
RSTP
4.4.2.1 RSTP Uses
STP
(
Spanning
Tree
Protocol
)
is
established
in
accordance
with
IEEE
802
.
1D
standard
.
It
is
developed
for
the
elimination
of
the
data
link
layer
loops
in
the
LAN
protocol
.
Devices
running
this
protocol
exchange
packets
with
each
other
to
find
loops
in
the
network
,
and
choose
to
block
some
certain
ports
.
This
will
eventually
make
the
loop
network
structure
into
a
loop
-
free
tree
pruning
network
structure
.
Thus
it
prevents
packet
proliferation
and
infinite cycling
in
loop
network
,
avoiding
declined processing
capacity and receiving same messages repeatly
.
Caution
Configuration
Guide
:
Such
as
connect
the
switch
A’s
1
-
2
ports
with
switch
B’s
1
-
2
ports
Enable
a
convergence
group
in
switch
A
;
Select
1
and
2
ports;
Click
Save;
Switch
B
and
Switch
A
are
in
consistent
procedure;
End.
4.4.2.2 STP Basic Concept
(
1
)
The
root
bridge
Network
structure
tree
must
have
a
root
,
then
STP
introduces
the
concept
of
root
bridge
in
.
Only
one
root
bridge
and
the
root
bridge
will
change
when
the
network
topology
changes
,
so
the
root
bridge
is
not
fixed
.
(
2
)
The
path
cost
Path
cost
is
a
reference
value
for
STP
to
select
a
link
.
By
calculating
the
path
cost
of
STP
,
STP chooses
stronger
links
to
block
redundant
links and
cut
the
network
into
a
loop
-
free
tree
topology
.
(
3
)
The
port
role
Root
port
:
responsible
for
forwarding
data
to
the
root
port
.
Designated
port
:
responsible
for
forwarding
data
to
the
downstream
of
network
segment
or
switch
port
.
Block
Port
:
port
suppressed
by
other
'
s
specific
ports
.
(
4
)
Port
status
Forwarding
:
Forwarding
user
traffic
,
only
the
root
port
or
designated
port
have
this
condition
.
Learning
:
The
switch
builds
the
MAC
address
table
according
to
user
traffic
received
(
but
not
forwarding
traffic
).
Listening
:
the
completion
of
the
root
bridge
,
select
the
root
port
and
designated
ports
.
Blocking
:
Only
BPDU
is
received
and
processed
,
no user
traffic forwarded
.
Disabled
:
consider
blocking
or
link
disconnection
.
(
5
)
The
designated
bridges
and
designated
ports
The meaning
of
designated
bridges
and
designated
ports is shown in
Table
4
-
7
below
.
25