cisco 640 802 ccna portable command guide 2008 phần 8 pps
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Spanning Tree Protocol 143
Configuring STP Timers
NOTE: For the hello-time command, the range is 1 to 10 seconds. The default is
2 seconds.
For the forward-time command, the range is 4 to 30 seconds. The default is 15
seconds.
For the max-age command, the range is 6 to 40 seconds. The default is 20
seconds.
CAUTION: Cisco recommends caution when using this command. Cisco further
recommends that the spanning-tree vlan
x root primary or the spanning-tree
vlan x root secondary command be used instead to modify the switch timers.
Verifying STP
Switch(config)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
vv
vv
ll
ll
aa
aa
nn
nn
55
55
hh
hh
ee
ee
ll
ll
ll
ll
oo
oo
tt
tt
ii
ii
mm
mm
ee
ee
44
44
Changes the hello-delay timer to 4
seconds on VLAN 5
Switch(config)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
vv
vv
ll
ll
aa
aa
nn
nn
55
55
ff
ff
oo
oo
rr
rr
ww
ww
aa
aa
rr
rr
dd
dd
tt
tt
ii
ii
mm
mm
ee
ee
22
22
00
00
Changes the forward-delay timer
to 20 seconds on VLAN 5
Switch(config)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
vv
vv
ll
ll
aa
aa
nn
nn
55
55
mm
mm
aa
aa
xx
xx
aa
aa
gg
gg
ee
ee
22
22
55
55
Changes the maximum-aging timer
to 25 seconds on VLAN 5
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
Displays STP information
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
aa
aa
cc
cc
tt
tt
ii
ii
vv
vv
ee
ee
Displays STP information on active
interfaces only
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
bb
bb
rr
rr
ii
ii
ee
ee
ff
ff
Displays a brief status of the STP
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
dd
dd
ee
ee
tt
tt
aa
aa
ii
ii
ll
ll
Displays a detailed summary of
interface information
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
gg
gg
ii
ii
gg
gg
aa
aa
bb
bb
ii
ii
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
11
11
Displays STP information for
interface gigabitethernet 0/1
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
ss
ss
uu
uu
mm
mm
mm
mm
aa
aa
rr
rr
yy
yy
Displays a summary of port states
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
ss
ss
uu
uu
mm
mm
mm
mm
aa
aa
rr
rr
yy
yy
tt
tt
oo
oo
tt
tt
aa
aa
ll
ll
ss
ss
Displays the total lines of the STP
section
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
vv
vv
ll
ll
aa
aa
nn
nn
55
55
Displays STP information for
VLAN 5
144 Spanning Tree Protocol
Optional STP Configurations
Although the following commands are not mandatory for STP to work, you might find these
helpful to fine-tune your network.
PortFast
BPDU Guard
Switch(config)#ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
11
11
00
00
Moves to interface configuration mode.
Switch(config-if)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
pp
pp
oo
oo
rr
rr
tt
tt
ff
ff
aa
aa
ss
ss
tt
tt
Enables PortFast on an access port.
Switch(config-if)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
pp
pp
oo
oo
rr
rr
tt
tt
ff
ff
aa
aa
ss
ss
tt
tt
tt
tt
rr
rr
uu
uu
nn
nn
kk
kk
Enables PortFast on a trunk port.
WARNING: Use the portfast command only
when connecting a single end station to an
access or trunk port. Using this command on a
port connected to a switch or hub could prevent
spanning tree from detecting loops.
NOTE: If you enable the voice VLAN feature,
PortFast is enabled automatically. If you disable
voice VLAN, PortFast is still enabled.
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
11
11
00
00
pp
pp
oo
oo
rr
rr
tt
tt
ff
ff
aa
aa
ss
ss
tt
tt
Displays PortFast information on interface
fastethernet 0/10.
Switch(config)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
pp
pp
oo
oo
rr
rr
tt
tt
ff
ff
aa
aa
ss
ss
tt
tt
bb
bb
pp
pp
dd
dd
uu
uu
gg
gg
uu
uu
aa
aa
rr
rr
dd
dd
dd
dd
ee
ee
ff
ff
aa
aa
uu
uu
ll
ll
tt
tt
Globally enables BPDU Guard.
Switch(config)#ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
rr
rr
aa
aa
nn
nn
gg
gg
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
11
11
––
––
55
55
Enters interface range configuration mode.
Switch(config-if-
range)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
pp
pp
oo
oo
rr
rr
tt
tt
ff
ff
aa
aa
ss
ss
tt
tt
Enables PortFast on all interfaces in the range.
NOTE: By default, BPDU Guard is disabled.
Switch(config)#ee
ee
rr
rr
rr
rr
dd
dd
ii
ii
ss
ss
aa
aa
bb
bb
ll
ll
ee
ee
rr
rr
ee
ee
cc
cc
oo
oo
vv
vv
ee
ee
rr
rr
yy
yy
cc
cc
aa
aa
uu
uu
ss
ss
ee
ee
bb
bb
pp
pp
dd
dd
uu
uu
gg
gg
uu
uu
aa
aa
rr
rr
dd
dd
Allows port to reenable itself if the cause of the
error is BPDU Guard by setting a recovery timer.
Spanning Tree Protocol 145
Changing the Spanning-Tree Mode
Different types of spanning tree can be configured on a Cisco switch. The options vary
according to the platform:
• Per-VLAN Spanning Tree (PVST)—There is one instance of spanning tree for each
VLAN. This is a Cisco proprietary protocol.
• Per-VLAN Spanning Tree Plus (PVST+)—Also Cisco proprietary. Has added
extensions to the PVST protocol.
• Rapid PVST+—This mode is the same as PVST+ except that it uses a rapid
convergence based on the 802.1w standard.
• Multiple Spanning Tree Protocol (MSTP)—IEEE 802.1s. Extends the 802.1w
Rapid Spanning Tree (RST) algorithm to multiple spanning trees. Multiple VLANs
can map to a single instance of RST. You cannot run MSTP and PVST at the same
time.
Switch(config)#ee
ee
rr
rr
rr
rr
dd
dd
ii
ii
ss
ss
aa
aa
bb
bb
ll
ll
ee
ee
rr
rr
ee
ee
cc
cc
oo
oo
vv
vv
ee
ee
rr
rr
yy
yy
ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
vv
vv
aa
aa
ll
ll
44
44
00
00
00
00
Sets recovery timer to 400 seconds. The default
is 300 seconds. The range is from 30 to 86400
seconds.
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
ss
ss
uu
uu
mm
mm
mm
mm
aa
aa
rr
rr
yy
yy
tt
tt
oo
oo
tt
tt
aa
aa
ll
ll
ss
ss
Verifies whether BPDU Guard is enabled or
disabled.
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ee
ee
rr
rr
rr
rr
dd
dd
ii
ii
ss
ss
aa
aa
bb
bb
ll
ll
ee
ee
rr
rr
ee
ee
cc
cc
oo
oo
vv
vv
ee
ee
rr
rr
yy
yy
Displays errdisable recovery timer information.
Switch(config)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
mm
mm
oo
oo
dd
dd
ee
ee
mm
mm
ss
ss
tt
tt
Enables MSTP. This command is
available only on a switch running the EI
software image.
Switch(config)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
mm
mm
oo
oo
dd
dd
ee
ee
pp
pp
vv
vv
ss
ss
tt
tt
Enables PVST. This is the default
setting.
Switch(config)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
mm
mm
oo
oo
dd
dd
ee
ee
rr
rr
aa
aa
pp
pp
ii
ii
dd
dd
pp
pp
vv
vv
ss
ss
tt
tt
Enables Rapid PVST+.
146 Spanning Tree Protocol
Extended System ID
Enabling Rapid Spanning Tree
Switch(config)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
ee
ee
xx
xx
tt
tt
ee
ee
nn
nn
dd
dd
ss
ss
yy
yy
ss
ss
tt
tt
ee
ee
mm
mm
ii
ii
dd
dd
Enables extended system ID, also known as MAC
address reduction.
NOTE: Catalyst switches running software
earlier than Cisco IOS Software Release 12.1(8)
EA1 do not support the extended system ID.
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
ss
ss
uu
uu
mm
mm
mm
mm
aa
aa
rr
rr
yy
yy
Verifies extended system ID is enabled.
Switch#ss
ss
hh
hh
oo
oo
ww
ww
rr
rr
uu
uu
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
Verifies extended system ID is enabled.
Switch(config)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
mm
mm
oo
oo
dd
dd
ee
ee
rr
rr
aa
aa
pp
pp
ii
ii
dd
dd
pp
pp
vv
vv
ss
ss
tt
tt
Enables Rapid PVST+.
Switch(config)#ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
11
11
Moves to interface configuration mode.
Switch(config-if)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
ss
ss
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
ll
ll
ii
ii
nn
nn
kk
kk
tt
tt
yy
yy
pp
pp
ee
ee
pp
pp
oo
oo
ii
ii
nn
nn
tt
tt
tt
tt
oo
oo
pp
pp
oo
oo
ii
ii
nn
nn
tt
tt
Sets the interface to be a point-to-point
interface.
NOTE: By setting the link type to point to
point, this means that if you connect this
port to a remote port, and this port becomes
a designated port, the switch negotiates
with the remote port and transitions the
local port to a forwarding state.
Switch(config-if)#ee
ee
xx
xx
ii
ii
tt
tt
Switch(config)#cc
cc
ll
ll
ee
ee
aa
aa
rr
rr
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
dd
dd
ee
ee
tt
tt
ee
ee
cc
cc
tt
tt
ee
ee
dd
dd
pp
pp
rr
rr
oo
oo
tt
tt
oo
oo
cc
cc
oo
oo
ll
ll
ss
ss
NOTE: The clear spanning-tree
detected-protocols command restarts the
protocol-migration process on the switch if
any port is connected to a port on a legacy
802.1D switch.
Spanning Tree Protocol 147
Troubleshooting Spanning Tree
Configuration Example: STP
Figure 14-1 illustrates the network topology for the configuration that follows, which shows
how to configure STP using commands covered in this chapter.
Switch#dd
dd
ee
ee
bb
bb
uu
uu
gg
gg
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
aa
aa
ll
ll
ll
ll
Displays all spanning-tree debugging
events
Switch#dd
dd
ee
ee
bb
bb
uu
uu
gg
gg
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
ee
ee
vv
vv
ee
ee
nn
nn
tt
tt
ss
ss
Displays spanning-tree debugging
topology events
Switch#dd
dd
ee
ee
bb
bb
uu
uu
gg
gg
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
bb
bb
aa
aa
cc
cc
kk
kk
bb
bb
oo
oo
nn
nn
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
Displays spanning-tree debugging
BackboneFast events
Switch#dd
dd
ee
ee
bb
bb
uu
uu
gg
gg
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
uu
uu
pp
pp
ll
ll
ii
ii
nn
nn
kk
kk
ff
ff
aa
aa
ss
ss
tt
tt
Displays spanning-tree debugging
UplinkFast event
Switch#dd
dd
ee
ee
bb
bb
uu
uu
gg
gg
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
mm
mm
ss
ss
tt
tt
pp
pp
aa
aa
ll
ll
ll
ll
Displays all MST debugging events
Switch#dd
dd
ee
ee
bb
bb
uu
uu
gg
gg
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
ss
ss
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
ss
ss
tt
tt
aa
aa
tt
tt
ee
ee
Displays spanning-tree port state
changes
Switch#dd
dd
ee
ee
bb
bb
uu
uu
gg
gg
ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
pp
pp
vv
vv
ss
ss
tt
tt
++
++
Displays PVST+ events
148 Spanning Tree Protocol
Figure 14-4 Network Topology for STP Configuration Example
VTP
Domain
stpdemo
fa0/13
fa0/8
fa0/5 fa0/5
fa0/8
fa0/8
1
16
g0/1
20 10
1
g0/1
10
1
10
20
20
1
10
g0/1
1
20
g0/2
VTP Client
VLAN 10 Root Primary
Distribution1 (2960)
Core (2960)
VLAN 1 Root Primary
VTP Server
VTP Client
VLAN 20 Root Primary
Distribution2 (2960)
VLAN 10 - Forwarding VLAN 10 - Blocking
Spanning Tree Protocol 149
Core Switch (2960)
Distribution 1 Switch (2960)
Switch>ee
ee
nn
nn
aa
aa
bb
bb
ll
ll
ee
ee
Moves to privileged mode.
Switch#cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
uu
uu
rr
rr
ee
ee
tt
tt
ee
ee
rr
rr
mm
mm
ii
ii
nn
nn
aa
aa
ll
ll
Moves to global configuration mode.
Switch(config)#hh
hh
oo
oo
ss
ss
tt
tt
nn
nn
aa
aa
mm
mm
ee
ee
CC
CC
oo
oo
rr
rr
ee
ee
Sets the host name.
Core(config)#nn
nn
oo
oo
ii
ii
pp
pp
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
ll
ll
oo
oo
oo
oo
kk
kk
uu
uu
pp
pp
Turns off Dynamic Name System (DNS)
queries so that spelling mistakes do not slow
you down.
Core(config)#vv
vv
tt
tt
pp
pp
mm
mm
oo
oo
dd
dd
ee
ee
ss
ss
ee
ee
rr
rr
vv
vv
ee
ee
rr
rr
Changes the switch to VTP server mode. This
is the default mode.
Core(config)#vv
vv
tt
tt
pp
pp
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
ss
ss
tt
tt
pp
pp
dd
dd
ee
ee
mm
mm
oo
oo
Configures the VTP domain name to stpdemo.
Core(config)#vv
vv
ll
ll
aa
aa
nn
nn
11
11
00
00
Creates VLAN 10 and enters VLAN
configuration mode.
Core(config-vlan)#nn
nn
aa
aa
mm
mm
ee
ee
AA
AA
cc
cc
cc
cc
oo
oo
uu
uu
nn
nn
tt
tt
ii
ii
nn
nn
gg
gg
Assigns a name to the VLAN.
Core(config-vlan)#ee
ee
xx
xx
ii
ii
tt
tt
Returns to global configuration mode.
Core(config)#vv
vv
ll
ll
aa
aa
nn
nn
22
22
00
00
Creates VLAN 20 and enters VLAN
configuration mode.
Core(config-vlan)#nn
nn
aa
aa
mm
mm
ee
ee
MM
MM
aa
aa
rr
rr
kk
kk
ee
ee
tt
tt
ii
ii
nn
nn
gg
gg
Assigns a name to the VLAN.
Core(config-vlan)#ee
ee
xx
xx
ii
ii
tt
tt
Returns to global configuration mode.
Core(config)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
vv
vv
ll
ll
aa
aa
nn
nn
11
11
rr
rr
oo
oo
oo
oo
tt
tt
pp
pp
rr
rr
ii
ii
mm
mm
aa
aa
rr
rr
yy
yy
Configures the switch to become the root
switch for VLAN 1.
Core(config)#ee
ee
xx
xx
ii
ii
tt
tt
Returns to privileged mode.
Core#cc
cc
oo
oo
pp
pp
yy
yy
rr
rr
uu
uu
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
ss
ss
tt
tt
aa
aa
rr
rr
tt
tt
uu
uu
pp
pp
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
Saves the configuration to NVRAM.
Switch>ee
ee
nn
nn
aa
aa
bb
bb
ll
ll
ee
ee
Moves to privileged mode.
Switch#cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
uu
uu
rr
rr
ee
ee
tt
tt
ee
ee
rr
rr
mm
mm
ii
ii
nn
nn
aa
aa
ll
ll
Moves to global configuration mode.
Switch(config)#hh
hh
oo
oo
ss
ss
tt
tt
nn
nn
aa
aa
mm
mm
ee
ee
DD
DD
ii
ii
ss
ss
tt
tt
rr
rr
ii
ii
bb
bb
uu
uu
tt
tt
ii
ii
oo
oo
nn
nn
11
11
Sets the host name.
Distribution1(config)#nn
nn
oo
oo
ii
ii
pp
pp
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
ll
ll
oo
oo
oo
oo
kk
kk
uu
uu
pp
pp
Turns off DNS queries so that spelling
mistakes do not slow you down.
150 EtherChannel
Distribution 2 Switch (2960)
EtherChannel
EtherChannel provides fault-tolerant, high-speed links between switches, routers, and
servers. An EtherChannel consists of individual Fast Ethernet or Gigabit Ethernet links
bundled into a single logical link. If a link within an EtherChannel fails, traffic previously
carried over that failed link changes to the remaining links within the EtherChannel.
Distribution1(config)#vv
vv
tt
tt
pp
pp
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
ss
ss
tt
tt
pp
pp
dd
dd
ee
ee
mm
mm
oo
oo
Configures the VTP domain name to
stpdemo.
Distribution1(config)#vv
vv
tt
tt
pp
pp
mm
mm
oo
oo
dd
dd
ee
ee
cc
cc
ll
ll
ii
ii
ee
ee
nn
nn
tt
tt
Changes the switch to VTP client mode.
Distribution1(config)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
vv
vv
ll
ll
aa
aa
nn
nn
11
11
00
00
rr
rr
oo
oo
oo
oo
tt
tt
pp
pp
rr
rr
ii
ii
mm
mm
aa
aa
rr
rr
yy
yy
Configures the switch to become the root
switch of VLAN 10.
Distribution1(config)#ee
ee
xx
xx
ii
ii
tt
tt
Returns to privileged mode.
Distribution1#cc
cc
oo
oo
pp
pp
yy
yy
rr
rr
uu
uu
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
ss
ss
tt
tt
aa
aa
rr
rr
tt
tt
uu
uu
pp
pp
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
Saves the configuration to NVRAM.
Switch>ee
ee
nn
nn
aa
aa
bb
bb
ll
ll
ee
ee
Moves to privileged mode.
Switch#cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
uu
uu
rr
rr
ee
ee
tt
tt
ee
ee
rr
rr
mm
mm
ii
ii
nn
nn
aa
aa
ll
ll
Moves to global configuration mode.
Switch(config)#hh
hh
oo
oo
ss
ss
tt
tt
nn
nn
aa
aa
mm
mm
ee
ee
DD
DD
ii
ii
ss
ss
tt
tt
rr
rr
ii
ii
bb
bb
uu
uu
tt
tt
ii
ii
oo
oo
nn
nn
22
22
Sets the host name.
Distribution2(config)#nn
nn
oo
oo
ii
ii
pp
pp
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
ll
ll
oo
oo
oo
oo
kk
kk
uu
uu
pp
pp
Turns off DNS queries so that spelling
mistakes do not slow you down.
Distribution2(config)#vv
vv
tt
tt
pp
pp
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
ss
ss
tt
tt
pp
pp
dd
dd
ee
ee
mm
mm
oo
oo
Configures the VTP domain name to
stpdemo.
Distribution2(config)#vv
vv
tt
tt
pp
pp
mm
mm
oo
oo
dd
dd
ee
ee
cc
cc
ll
ll
ii
ii
ee
ee
nn
nn
tt
tt
Changes the switch to VTP client mode.
Distribution2(config)#ss
ss
pp
pp
aa
aa
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
tt
tt
rr
rr
ee
ee
ee
ee
vv
vv
ll
ll
aa
aa
nn
nn
22
22
00
00
rr
rr
oo
oo
oo
oo
tt
tt
pp
pp
rr
rr
ii
ii
mm
mm
aa
aa
rr
rr
yy
yy
Configures the switch to become the root
switch of VLAN 20.
Distribution2(config)#ee
ee
xx
xx
ii
ii
tt
tt
Returns to privileged mode.
Distribution2#cc
cc
oo
oo
pp
pp
yy
yy
rr
rr
uu
uu
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
ss
ss
tt
tt
aa
aa
rr
rr
tt
tt
uu
uu
pp
pp
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
Saves the configuration to NVRAM.
EtherChannel 151
Interface Modes in EtherChannel
Guidelines for Configuring EtherChannel
• PAgP is Cisco proprietary.
• LACP is defined in 802.3ad.
• You can combine from two to eight parallel links.
• All ports must be identical:
— Same speed and duplex
— Cannot mix Fast Ethernet and Gigabit Ethernet
— Cannot mix PAgP and LACP
— Must all be VLAN trunk or nontrunk operational status
• All links must be either Layer 2 or Layer 3 in a single channel group.
• To create a channel in PAgP, sides must be set to
— Auto-Desirable
— Desirable-Desirable
• To create a channel in LACP, sides must be set to
— Active-Active
— Active-Passive
• To create a channel without using PAgP or LACP, sides must be set to On-On.
• Do not configure a GigaStack gigabit interface converter (GBIC) as part of an
EtherChannel.
Mode Protocol Description
On None Forces the interface into an EtherChannel without PAgP or
LACP. Channel only exists if connected to another interface
group also in On mode.
Auto PAgP Places the interface into a passive negotiating state—will
respond to PAgP packets but will not initiate PAgP
negotiation.
Desirable PAgP Places the interface into an active negotiating state—will send
PAgP packets to start negotiations.
Passive LACP Places the interface into a passive negotiating state—will
respond to LACP packets but will not initiate LACP
negotiation.
Active LACP Places the interface into an active negotiating state—will send
LACP packets to start negotiations.
152 EtherChannel
• An interface that is already configured to be a Switched Port Analyzer (SPAN)
destination port will not join an EtherChannel group until SPAN is disabled.
• Do not configure a secure port as part of an EtherChannel.
• Interfaces with different native VLANs cannot form an EtherChannel.
• When using trunk links, ensure all trunks are in the same mode—Inter-Switch Link
(ISL) or dot1q.
Configuring Layer 2 EtherChannel
Verifying EtherChannel
Switch(config)#ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
rr
rr
aa
aa
nn
nn
gg
gg
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
11
11
44
44
Moves to interface range
configuration mode.
Switch(config-if-range)#cc
cc
hh
hh
aa
aa
nn
nn
nn
nn
ee
ee
ll
ll
pp
pp
rr
rr
oo
oo
tt
tt
oo
oo
cc
cc
oo
oo
ll
ll
pp
pp
aa
aa
gg
gg
pp
pp
Specifies the PAgP protocol to be used
in this channel.
Or
Switch(config-if-range)#cc
cc
hh
hh
aa
aa
nn
nn
nn
nn
ee
ee
ll
ll
pp
pp
rr
rr
oo
oo
tt
tt
oo
oo
cc
cc
oo
oo
ll
ll
ll
ll
aa
aa
cc
cc
pp
pp
Specifies the LACP protocol to be
used in this channel.
Switch(config-if-range)#cc
cc
hh
hh
aa
aa
nn
nn
nn
nn
ee
ee
ll
ll
gg
gg
rr
rr
oo
oo
uu
uu
pp
pp
11
11
mm
mm
oo
oo
dd
dd
ee
ee
{dd
dd
ee
ee
ss
ss
ii
ii
rr
rr
aa
aa
bb
bb
ll
ll
ee
ee
| aa
aa
uu
uu
tt
tt
oo
oo
| oo
oo
nn
nn
| pp
pp
aa
aa
ss
ss
ss
ss
ii
ii
vv
vv
ee
ee
| aa
aa
cc
cc
tt
tt
ii
ii
vv
vv
ee
ee
}
Creates channel group 1 and assigns
interfaces 01–04 as part of it. Use
whichever mode is necessary,
depending on your choice of protocol.
Switch#ss
ss
hh
hh
oo
oo
ww
ww
rr
rr
uu
uu
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
Displays list of what is currently running on the
device
Switch#ss
ss
hh
hh
oo
oo
ww
ww
rr
rr
uu
uu
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
11
11
22
22
Displays interface fastethernet 0/12 information
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
cc
cc
hh
hh
aa
aa
nn
nn
nn
nn
ee
ee
ll
ll
Displays all EtherChannel information
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
cc
cc
hh
hh
aa
aa
nn
nn
nn
nn
ee
ee
ll
ll
11
11
pp
pp
oo
oo
rr
rr
tt
tt
cc
cc
hh
hh
aa
aa
nn
nn
nn
nn
ee
ee
ll
ll
Displays port channel information
Switch#ss
ss
hh
hh
oo
oo
ww
ww
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
cc
cc
hh
hh
aa
aa
nn
nn
nn
nn
ee
ee
ll
ll
ss
ss
uu
uu
mm
mm
mm
mm
aa
aa
rr
rr
yy
yy
Displays a summary of EtherChannel information
Switch#ss
ss
hh
hh
oo
oo
ww
ww
pp
pp
aa
aa
gg
gg
pp
pp
nn
nn
ee
ee
ii
ii
gg
gg
hh
hh
bb
bb
oo
oo
rr
rr
Shows PAgP neighbor information
Switch#cc
cc
ll
ll
ee
ee
aa
aa
rr
rr
pp
pp
aa
aa
gg
gg
pp
pp
11
11
cc
cc
oo
oo
uu
uu
nn
nn
tt
tt
ee
ee
rr
rr
ss
ss
Clears PAgP channel group 1 information
Switch#cc
cc
ll
ll
ee
ee
aa
aa
rr
rr
ll
ll
aa
aa
cc
cc
pp
pp
11
11
cc
cc
oo
oo
uu
uu
nn
nn
tt
tt
ee
ee
rr
rr
ss
ss
Clears LACP channel group 1 information
EtherChannel 153
Configuration Example: EtherChannel
Figure 14-2 illustrates the network topology for the configuration that follows, which shows
how to configure EtherChannel using commands covered in this chapter.
Figure 14-5 Network Topology for EtherChannel Configuration
ALSwitch1 (2960)
FEC
IEEE 802.1q
Trunk
FEC
IEEE 802.1q
Trunk
Core (2960)
172.16.10.2/24
fa0/6
fa0/12
fa0/6 fa0/12
WS1
Accounting
VLAN 10
fa0/5-8
172.16.10.0/24
172.16.20.2/24
WS2
Marketing
VLAN 20
fa0/9-12
172.16.20.0/24
ALSwitch2 (2960)
172.16.10.3/24
WS3
Accounting
VLAN 10
fa0/5-8
172.16.10.0/24
172.16.20.3/24
WS4
Marketing
VLAN 20
fa0/9-12
172.16.20.0/24
fa0/1
fa0/2
fa0/1
fa0/2
fa0/3
fa0/4
fa0/1
fa0/2
154 EtherChannel
Core (2960)
Switch>ee
ee
nn
nn
aa
aa
bb
bb
ll
ll
ee
ee
Moves to privileged mode
Switch#cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
uu
uu
rr
rr
ee
ee
tt
tt
ee
ee
rr
rr
mm
mm
ii
ii
nn
nn
aa
aa
ll
ll
Moves to global configuration mode
Switch(config)#hh
hh
oo
oo
ss
ss
tt
tt
nn
nn
aa
aa
mm
mm
ee
ee
CC
CC
oo
oo
rr
rr
ee
ee
Sets the host name
Core(config)#nn
nn
oo
oo
ii
ii
pp
pp
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
ll
ll
oo
oo
oo
oo
kk
kk
uu
uu
pp
pp
Turns off DNS queries so that spelling
mistakes do not slow you down
Core(config)#vv
vv
tt
tt
pp
pp
mm
mm
oo
oo
dd
dd
ee
ee
ss
ss
ee
ee
rr
rr
vv
vv
ee
ee
rr
rr
Changes the switch to VTP server mode
Core(config)#vv
vv
tt
tt
pp
pp
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
tt
tt
ee
ee
ss
ss
tt
tt
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
Configures the VTP domain name to
testdomain
Core(config)#vv
vv
ll
ll
aa
aa
nn
nn
11
11
00
00
Creates VLAN 10 and enters VLAN
configuration mode
Core(config-vlan)#nn
nn
aa
aa
mm
mm
ee
ee
AA
AA
cc
cc
cc
cc
oo
oo
uu
uu
nn
nn
tt
tt
ii
ii
nn
nn
gg
gg
Assigns a name to the VLAN
Core(config-vlan)#ee
ee
xx
xx
ii
ii
tt
tt
Returns to global configuration mode
Core(config)#vv
vv
ll
ll
aa
aa
nn
nn
22
22
00
00
Creates VLAN 20 and enters VLAN
configuration mode
Core(config-vlan)#nn
nn
aa
aa
mm
mm
ee
ee
MM
MM
aa
aa
rr
rr
kk
kk
ee
ee
tt
tt
ii
ii
nn
nn
gg
gg
Assigns a name to the VLAN
Core(config-vlan)#ee
ee
xx
xx
ii
ii
tt
tt
Returns to global configuration mode
Core(config)#ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
rr
rr
aa
aa
nn
nn
gg
gg
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
11
11
––
––
44
44
Moves to interface range configuration
mode
Core(config-if)#ss
ss
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
pp
pp
oo
oo
rr
rr
tt
tt
tt
tt
rr
rr
uu
uu
nn
nn
kk
kk
ee
ee
nn
nn
cc
cc
aa
aa
pp
pp
ss
ss
uu
uu
ll
ll
aa
aa
tt
tt
ii
ii
oo
oo
nn
nn
dd
dd
oo
oo
tt
tt
11
11
Specifies 802.1q encapsulation on the
trunk link
Core(config-if)#ss
ss
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
pp
pp
oo
oo
rr
rr
tt
tt
mm
mm
oo
oo
dd
dd
ee
ee
tt
tt
rr
rr
uu
uu
nn
nn
kk
kk
Puts the interface into permanent
trunking mode and negotiates to convert
the link into a trunk link
Core(config-if)#ee
ee
xx
xx
ii
ii
tt
tt
Returns to global configuration mode
Core(config)#ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
rr
rr
aa
aa
nn
nn
gg
gg
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
11
11
––
––
22
22
Moves to interface range configuration
mode
Core(config-if)#cc
cc
hh
hh
aa
aa
nn
nn
nn
nn
ee
ee
ll
ll
gg
gg
rr
rr
oo
oo
uu
uu
pp
pp
11
11
mm
mm
oo
oo
dd
dd
ee
ee
dd
dd
ee
ee
ss
ss
ii
ii
rr
rr
aa
aa
bb
bb
ll
ll
ee
ee
Creates channel group 1 and assigns
interfaces 01–02 as part of it
Core(config-if)#ee
ee
xx
xx
ii
ii
tt
tt
Moves to global configuration mode
EtherChannel 155
ALSwitch1 (2960)
Core(config)#ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
rr
rr
aa
aa
nn
nn
gg
gg
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
33
33
––
––
44
44
Moves to interface range configuration
mode
Core(config-if)#cc
cc
hh
hh
aa
aa
nn
nn
nn
nn
ee
ee
ll
ll
gg
gg
rr
rr
oo
oo
uu
uu
pp
pp
22
22
mm
mm
oo
oo
dd
dd
ee
ee
dd
dd
ee
ee
ss
ss
ii
ii
rr
rr
aa
aa
bb
bb
ll
ll
ee
ee
Creates channel group 2 and assigns
interfaces 03–04 as part of it
Core(config-if)#ee
ee
xx
xx
ii
ii
tt
tt
Moves to global configuration mode
Core(config)#ee
ee
xx
xx
ii
ii
tt
tt
Moves to privileged mode
Core#cc
cc
oo
oo
pp
pp
yy
yy
rr
rr
uu
uu
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
ss
ss
tt
tt
aa
aa
rr
rr
tt
tt
uu
uu
pp
pp
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
Saves the configuration to NVRAM
Switch>ee
ee
nn
nn
aa
aa
bb
bb
ll
ll
ee
ee
Moves to privileged mode
Switch#cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
uu
uu
rr
rr
ee
ee
tt
tt
ee
ee
rr
rr
mm
mm
ii
ii
nn
nn
aa
aa
ll
ll
Moves to global configuration mode
Switch(config)#hh
hh
oo
oo
ss
ss
tt
tt
nn
nn
aa
aa
mm
mm
ee
ee
AA
AA
LL
LL
SS
SS
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
11
11
Sets the host name
ALSwitch1(config)#nn
nn
oo
oo
ii
ii
pp
pp
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
ll
ll
oo
oo
oo
oo
kk
kk
uu
uu
pp
pp
Turns off DNS queries so that spelling
mistakes do not slow you down
ALSwitch1(config)#vv
vv
tt
tt
pp
pp
mm
mm
oo
oo
dd
dd
ee
ee
cc
cc
ll
ll
ii
ii
ee
ee
nn
nn
tt
tt
Changes the switch to VTP client mode
ALSwitch1(config)#vv
vv
tt
tt
pp
pp
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
tt
tt
ee
ee
ss
ss
tt
tt
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
Configures the VTP domain name to
testdomain
ALSwitch1(config)#ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
rr
rr
aa
aa
nn
nn
gg
gg
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
55
55
––
––
88
88
Moves to interface range configuration
mode
ALSwitch1(config-if-
range)#ss
ss
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
pp
pp
oo
oo
rr
rr
tt
tt
mm
mm
oo
oo
dd
dd
ee
ee
aa
aa
cc
cc
cc
cc
ee
ee
ss
ss
ss
ss
Sets ports 5–8 as access ports
ALSwitch1(config-if-
range)#ss
ss
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
pp
pp
oo
oo
rr
rr
tt
tt
aa
aa
cc
cc
cc
cc
ee
ee
ss
ss
ss
ss
vv
vv
ll
ll
aa
aa
nn
nn
11
11
00
00
Assigns ports to VLAN 10
ALSwitch1(config-if-range)#ee
ee
xx
xx
ii
ii
tt
tt
Moves to global configuration mode
ALSwitch1(config)#ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
rr
rr
aa
aa
nn
nn
gg
gg
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
99
99
––
––
11
11
22
22
Moves to interface range configuration
mode
ALSwitch1(config-if-
range)#ss
ss
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
pp
pp
oo
oo
rr
rr
tt
tt
mm
mm
oo
oo
dd
dd
ee
ee
aa
aa
cc
cc
cc
cc
ee
ee
ss
ss
ss
ss
Sets ports 9–12 as access ports
ALSwitch1(config-if-
range)#ss
ss
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
pp
pp
oo
oo
rr
rr
tt
tt
aa
aa
cc
cc
cc
cc
ee
ee
ss
ss
ss
ss
vv
vv
ll
ll
aa
aa
nn
nn
22
22
00
00
Assigns ports to VLAN 20
156 EtherChannel
ALSwitch2 (2960)
ALSwitch1(config-if-range)#ee
ee
xx
xx
ii
ii
tt
tt
Moves to global configuration mode
ALSwitch1(config)#ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
rr
rr
aa
aa
nn
nn
gg
gg
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
11
11
––
––
22
22
Moves to interface range configuration
mode
ALSwitch1(config-if-
range)#ss
ss
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
pp
pp
oo
oo
rr
rr
tt
tt
mm
mm
oo
oo
dd
dd
ee
ee
tt
tt
rr
rr
uu
uu
nn
nn
kk
kk
Puts the interface into permanent
trunking mode and negotiates to convert
the link into a trunk link
ALSwitch1(config-if-
range)#cc
cc
hh
hh
aa
aa
nn
nn
nn
nn
ee
ee
ll
ll
gg
gg
rr
rr
oo
oo
uu
uu
pp
pp
11
11
mm
mm
oo
oo
dd
dd
ee
ee
dd
dd
ee
ee
ss
ss
ii
ii
rr
rr
aa
aa
bb
bb
ll
ll
ee
ee
Creates channel group 1 and assigns
interfaces 01–02 as part of it
ALSwitch1(config-if-range)#ee
ee
xx
xx
ii
ii
tt
tt
Moves to global configuration mode
ALSwitch1(config)#ee
ee
xx
xx
ii
ii
tt
tt
Moves to privileged mode
ALSwitch1#cc
cc
oo
oo
pp
pp
yy
yy
rr
rr
uu
uu
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
ss
ss
tt
tt
aa
aa
rr
rr
tt
tt
uu
uu
pp
pp
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
Saves the configuration to NVRAM
Switch>ee
ee
nn
nn
aa
aa
bb
bb
ll
ll
ee
ee
Moves to privileged mode
Switch#cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
uu
uu
rr
rr
ee
ee
tt
tt
ee
ee
rr
rr
mm
mm
ii
ii
nn
nn
aa
aa
ll
ll
Moves to global configuration mode
Switch(config)#hh
hh
oo
oo
ss
ss
tt
tt
nn
nn
aa
aa
mm
mm
ee
ee
AA
AA
LL
LL
SS
SS
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
22
22
Sets the host name
ALSwitch2(config)#nn
nn
oo
oo
ii
ii
pp
pp
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
ll
ll
oo
oo
oo
oo
kk
kk
uu
uu
pp
pp
Turns off DNS queries so that
spelling mistakes do not slow you
down
ALSwitch2(config)#vv
vv
tt
tt
pp
pp
mm
mm
oo
oo
dd
dd
ee
ee
cc
cc
ll
ll
ii
ii
ee
ee
nn
nn
tt
tt
Changes the switch to VTP client
mode
ALSwitch2(config)#vv
vv
tt
tt
pp
pp
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
tt
tt
ee
ee
ss
ss
tt
tt
dd
dd
oo
oo
mm
mm
aa
aa
ii
ii
nn
nn
Configures the VTP domain name to
testdomain
ALSwitch2(config)#ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
rr
rr
aa
aa
nn
nn
gg
gg
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
55
55
––
––
88
88
Moves to interface range
configuration mode
ALSwitch2(config-if-range)#ss
ss
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
pp
pp
oo
oo
rr
rr
tt
tt
mm
mm
oo
oo
dd
dd
ee
ee
aa
aa
cc
cc
cc
cc
ee
ee
ss
ss
ss
ss
Sets ports 5–8 as access ports
ALSwitch2(config-if-range)#ss
ss
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
pp
pp
oo
oo
rr
rr
tt
tt
aa
aa
cc
cc
cc
cc
ee
ee
ss
ss
ss
ss
vv
vv
ll
ll
aa
aa
nn
nn
11
11
00
00
Assigns ports to VLAN 10
ALSwitch2(config-if-range)#ee
ee
xx
xx
ii
ii
tt
tt
Moves to global configuration mode
EtherChannel 157
ALSwitch2(config)#ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
rr
rr
aa
aa
nn
nn
gg
gg
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
99
99
––
––
11
11
22
22
Moves to interface range
configuration mode
ALSwitch2(config-if-range)#ss
ss
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
pp
pp
oo
oo
rr
rr
tt
tt
mm
mm
oo
oo
dd
dd
ee
ee
aa
aa
cc
cc
cc
cc
ee
ee
ss
ss
ss
ss
Sets ports 9–12 as access ports
ALSwitch2(config-if-range)#ss
ss
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
pp
pp
oo
oo
rr
rr
tt
tt
aa
aa
cc
cc
cc
cc
ee
ee
ss
ss
ss
ss
vv
vv
ll
ll
aa
aa
nn
nn
22
22
00
00
Assigns ports to VLAN 20
ALSwitch2(config-if-range)#ee
ee
xx
xx
ii
ii
tt
tt
Moves to global configuration mode
ALSwitch2(config)#ii
ii
nn
nn
tt
tt
ee
ee
rr
rr
ff
ff
aa
aa
cc
cc
ee
ee
rr
rr
aa
aa
nn
nn
gg
gg
ee
ee
ff
ff
aa
aa
ss
ss
tt
tt
ee
ee
tt
tt
hh
hh
ee
ee
rr
rr
nn
nn
ee
ee
tt
tt
00
00
//
//
11
11
––
––
22
22
Moves to interface range
configuration mode
ALSwitch2(config-if-range)#ss
ss
ww
ww
ii
ii
tt
tt
cc
cc
hh
hh
pp
pp
oo
oo
rr
rr
tt
tt
mm
mm
oo
oo
dd
dd
ee
ee
tt
tt
rr
rr
uu
uu
nn
nn
kk
kk
Puts the interface into permanent
trunking mode and negotiates to
convert the link into a trunk link
ALSwitch2(config-if-range)#cc
cc
hh
hh
aa
aa
nn
nn
nn
nn
ee
ee
ll
ll
gg
gg
rr
rr
oo
oo
uu
uu
pp
pp
11
11
mm
mm
oo
oo
dd
dd
ee
ee
dd
dd
ee
ee
ss
ss
ii
ii
rr
rr
aa
aa
bb
bb
ll
ll
ee
ee
Creates channel group 1 and assigns
interfaces 01–02 as part of it.
ALSwitch2(config-if-range)#ee
ee
xx
xx
ii
ii
tt
tt
Moves to global configuration mode
ALSwitch2(config)#ee
ee
xx
xx
ii
ii
tt
tt
Moves to privileged mode
ALSwitch2#cc
cc
oo
oo
pp
pp
yy
yy
rr
rr
uu
uu
nn
nn
nn
nn
ii
ii
nn
nn
gg
gg
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
ss
ss
tt
tt
aa
aa
rr
rr
tt
tt
uu
uu
pp
pp
cc
cc
oo
oo
nn
nn
ff
ff
ii
ii
gg
gg
Saves the configuration to NVRAM
This page intentionally left blank
PART VI
Extending the LAN
Chapter 15 Implementing a Wireless LAN
This page intentionally left blank
CHAPTER 15
Implementing a
Wireless LAN
This chapter provides information and commands concerning the following topics:
• Wireless access point configuration: Linksys 300N access point
• Wireless client configuration: Linksys Wireless-N Notebook Adapter
NOTE: This chapter contains information that is not part of the objective list
of knowledge needed for passing the CCNA 640-901 certification exam.
However, the Cisco Networking Academy Program has included these topics
as part of its curriculum. Therefore, this chapter is provided to you as
valuable reference information only—the configuration of a wireless access
point or a wireless client is not evaluated on the CCNA certification exam.
Wireless Access Point Configuration: Linksys 300N Access Point
NOTE: The wireless access point (AP) used in this chapter is the Linksys
Wireless-N Broadband Router. If you are using a different AP, the screen cap-
tures shown here may differ.
It is important to use the most up-to-date firmware or drivers. This is espe-
cially true for the 300N AP because the 802.11n technology is still in draft
stage. Therefore, check the AP manufacturer website for available updates.
In the case of Linksys, its website for updates is />download.
Figure 15-1 shows the initial screen of the Setup Wizard, which runs automatically
when you use the installation CD provided with the AP. Run the Setup Wizard on the
computer before you plug in any cables to your AP or cable modem.
Figure 15-2 shows the license agreement for the device. After you have read the
agreement, click Next to continue, or Exit to exit the setup program.
162 Wireless Access Point Configuration: Linksys 300N Access Point
Figure 15-6 GUI Setup Wizard
Figure 15-7 License Agreement
Figure 15-3 shows the wizard asking you to unplug the power from your modem. When you
have finished, click Next.
Wireless Access Point Configuration: Linksys 300N Access Point 163
Figure 15-8 Unplugging Power to the Modem
Figure 15-4 shows the wizard asking you to unplug the modem from your computer. When
you have finished, click Next.
Figure 15-9 Disconnecting the Modem from the Computer
164 Wireless Access Point Configuration: Linksys 300N Access Point
In the next screen, shown in Figure 15-5, the wizard directs you to connect the modem to
the router.
Figure 15-10 Connect the Modem to the Router
The screen in Figure 15-6 shows the wizard asking you to plug power back into the modem.
Figure 15-11 Connect the Power to the Modem
Wireless Access Point Configuration: Linksys 300N Access Point 165
In the screens shown in Figure 15-7 and Figure 15-8, the wizard asks you to connect your
router to a computer. To install this device correctly, you must have a wired connection to
it. After this, you can configure the device to accept wireless clients.
The 300N has the RJ45 ports colored coded for ease of use—the port to connect to the
modem is blue, and the four ports that you can use to connect to devices are yellow. Check
with your device to make sure you are plugged into the correct ports.
Figure 15-12 Connect the Router to a Computer
Now that you have wired the Linksys router to your computer and modem, connect the
power cord to the router and plug it into the wall, as instructed in the screen shown in
Figure 15-9.
166 Wireless Access Point Configuration: Linksys 300N Access Point
Figure 15-13 Connect the Router to a Computer
Figure 15-14 Power on the Router
At this point, the wizard asks for you to check the status of the router to verify that the
correct LEDs are lit. At this point, if you need to start over, or if you need to review your
