?Basics
ip address ip-address subnet-mask
ip default-gateway ip-address
hostname string
prompt string
?CDP
Default CDP Configuration
CDP global state Enabled
CDP interface state Enabled
CDP timer (packet update frequency) 60 seconds
CDP holdtime (before discarding) 180 seconds
CDP version-2 advertisements Enabled
cdp timer seconds (Optional)
Set the transmission frequency of CDP updates in seconds.
The range is from 5 to 254; the default is 60 seconds.
cdp holdtime seconds (Optional)
Specify the amount of time a receiving device should hold the information sent by
your device before discarding it.
The range is from 10 to 255 seconds; the default is 180 seconds.
cdp advertise-v2 (Optional)
Configure CDP to send version-2 advertisements. This is the default state.
?DNS
ip name-server server-address1
ip domain-name name
ip domain-lookup
?SNMP
snmp-server host host-addr {traps informs} {version {1 2c}} community-string notification-type
recipient of the trap message.
snmp-server enable traps mac-notification
send MAC address traps to
snmp-server enable traps mac-notification
Enable the switch to send MAC address traps
mac-address-table notification
Enable the MAC address notification feature.
mac-address-table notification [interval value] [history-size value]
Enter the trap interval time and the history table size.
snmp trap mac-notification {added removed}
Enable the MAC address notification trap.
Switch(config)# snmp-server host 172.20.10.10 traps private
Switch(config)# snmp-server enable traps mac-notification
Switch(config)# mac-address-table notification
Switch(config)# mac-address-table notification interval 60
Switch(config)# mac-address-table notification history-size 100
Switch(config)# interface fastethernet0/4
Switch(config-if)# snmp trap mac-notification added
mac-address-table static mac-addr vlan vlan-id interface interface-id
Add a static address to the MAC address table.
show mac-address-table address
Displays MAC address table information for the specified MAC address.
show mac-address-table aging-time
Displays the aging time in all VLANs or the specified VLAN.
show mac-address-table count
Displays the number of addresses present in all VLANs or the specified VLAN.
show mac-address-table dynamic
Displays dynamic MAC address table entries only.
show mac-address-table interface
Displays the MAC address table information for the specified interface.
show mac-address-table multicast
Displays the Layer 2 multicast entries for all VLANs or the specified VLAN.
show mac-address-table static
Displays static MAC address table entries only.
show mac-address-table vlan
Displays the MAC address table information for the specified VLAN.
snmp-server community private RW
snmp-server community public RO
snmp-server community private@es0 RW
snmp-server community public@es0 RO
snmp-server chassis-id 0x12
?NTP
Configure the switch to synchronize only to devices providing authentication key 42
in the device? NTP packets:
Switch(config)# ntp authenticate
Switch(config)# ntp authentication-key 42 md5 aNiceKey
Switch(config)# ntp trusted-key 42
An NTP association can be a peer association (this switch can either synchronize to
the other device or allow the other device to synchronize to it), or it can be a
server association (meaning that only this switch synchronizes to the other device,
and not the other way around).
ntp peer ip-address [version number] [key keyid] [source interface] [prefer]
ntp server ip-address [version number] [key keyid] [source interface] [prefer]
ntp broadcast client
ntp broadcastdelay microseconds
ntp broadcast [version number] [key keyid] [destination-address]
ntp Access-group {query-only serve-only serve peer} access-list-number
NTP services are enabled on all interfaces by default.
ntp disable
ntp source type number
?SDM
By using Switch Database Management (SDM) templates, you can configure memory
resources in the switch to optimize support for specific features, depending on how
the switch is used in your network.
The four templates prioritize system memory to optimize support for these types of features:
?QoS and security ACEs?he access template might typically be used in an access switch at the network edge where the route table sizes might not be substantial. Filtering and QoS might be more important because an access
switch is the entry to the whole network.
?Routing?he routing template maximizes system resources for unicast routing,
typically required for a router or aggregator in the center of a network.
?VLANs?he VLAN template disables routing and supports the maximum number of
unicast MAC addresses. It would typically be selected for a Catalyst 3550
used as a Layer 2 switch.
?Default?he default template gives balance to all functionalities (QoS, ACLs,
unicast routing, multicast routing, VLANs and MAC addresses).
sdm prefer {access routing vlan}
1.1. Vlan's
?Normal VLAN's
To configure normal-range VLANs (VLAN IDs 1 to 1005), use the vlan vlan-id global
configuration command to enter config-vlan mode or the vlan database
privileged EXEC command to enter VLAN configuration mode.
Add ports to a VLAN by using the switchport interface configuration commands:
Normal-range VLANs are identified with a number between 1 and 1001.
vlan database
vlan vlan-id name vlan-name
Assign a port to a VLAN in the VLAN
interface interface-id
switchport mode access
switchport access vlan vlan-id
?Extended VLAN's
The VLAN configurations for VLAN IDs 1 to 1005 are saved in the VLAN database.
To configure extended-range VLANs (VLAN IDs 1006 to 4094), you must use config-vlan
mode with V
