Cisco IOS Commands Flashcards
(244 cards)
1
Q
What is the Cisco IOS Command?
In user EXEC mode, lists the subset of commands that are available at that level.
A
? or help
2
Q
What is the Cisco IOS Command?
Applies the ACL to the vty line. The *{direction}* argument can have the value of eitherinorout**.
A
access-class {number} {**direction}
3
Q
What is the Cisco IOS Command?
Creates a standard ACL that permits all traffic from or to a specified network.
A
access-list {number}permit{ip_address} {wildcard_mask}
4
Q
What is the Cisco IOS Command?
Configures a standard ACL that permits a network.
A
access-list {acl_id}permit** {network} {wildcard_mask}
5
Q
What is the Cisco IOS Command?
Creates a numbered access list entry.
A
access-list {acl_id} permit {network}
6
Q
What is the Cisco IOS Command?
Allows the configuration of a message that is displayed just before login.
A
banner login
7
Q
What is the Cisco IOS Command?
Enables Cisco Discovery Protocol on an interface.
A
cdp enable
8
Q
What is the Cisco IOS Command?
Interface subcommands that enable [or disable] CDP for a particular interface.
A
[no] cdp enable
9
Q
What is the Cisco IOS Command?
Global commands that enable [or disable] CDP for the entire switch or router.
A
[no] cdp run
10
Q
What is the Cisco IOS Command?
Manages the system clock.
A
clock set
11
Q
What is the Cisco IOS Command?
Activates the configuration mode from the terminal.
A
configure terminal
12
Q
What is the Cisco IOS Command?
Enters global configuration mode.
A
configure terminal
13
Q
What is the Cisco IOS Command?
Saves the running configuration into NVRAM as the startup configuration
A
copy running-config startup-config
14
Q
What is the Cisco IOS Command?
Copies the switch running configuration file to another destination. A typical destination is the startup configuration.
A
copy running-config {destination}
15
Q
What is the Cisco IOS Command?
Generates an RSA crypto key pair.
A
crypto key generate rsa
16
Q
What is the Cisco IOS Command?
Generates the RSA key pairs to be used.
A
crypto key generate rsa
17
Q
What is the Cisco IOS Command?
Enables debugging of ICMP packets.
A
debug ip icmp
18
Q
What is the Cisco IOS Command?
OSPF subcommand to tell OSPF to create and advertise an OSPF default route, as long as the router has some default route (or to always advertise a default, if the always option is configured).
A
Default-information originate [always]
19
Q
What is the Cisco IOS Command?
Specifies the IP address of the default router for a DHCP client.
A
default-router {address}
20
Q
What is the Cisco IOS Command?
Deletes a file from flash memory.
A
delete {**name}
21
Q
What is the Cisco IOS Command?
Creates a deny access list entry.
A
deny [ip | tcp | udp] {source_network} {wildcard} {mask} {dst_network} {wildcard} {mask}
22
Q
What is the Cisco IOS Command?
Creates ACL statements for a named ACL. This one disallows.
A
deny {test conditions}
23
Q
What is the Cisco IOS Command?
Adds a descriptive comment to the configuration of an interface.
A
description
24
Q
What is the Cisco IOS Command?
Specifies the IP address of the DNS server that is available to a DHCP client.
A
dns-server {address}
25
# What is the Cisco IOS Command?
Executes user EXEC or privileged EXEC commands from global configuration mode or other configuration modes or submodes, in any configuration mode.
**do** *{**command}*
26
# What is the Cisco IOS Command?
Enables full duplex on an interface.
**duplex full**
27
# What is the Cisco IOS Command?
Interface subcommand that manually sets the interface duplex.
**duplex [auto | full | half]**
28
# What is the Cisco IOS Command?
Activates privileged EXEC mode. In privileged EXEC mode, more commands are available. This command requires you to enter the enable password if an enable password is configured.
**enable**
29
# What is the Cisco IOS Command?
Enters the privileged EXEC mode command interpreter.
**enable**
30
# What is the Cisco IOS Command?
Sets a password for entering privileged EXEC mode. The password is protected using strong MD5-type encryption.
**enable secret** *{**password}*
31
# What is the Cisco IOS Command?
Configures the enable password in encrypted form.
**enable secret** *{password}*
32
# What is the Cisco IOS Command?
Sets the encapsulation type and VLAN on a subinterface on a router.
**encapsulation dot1q** *{vlan}* **[native]**
33
# What is the Cisco IOS Command?
Enables IEEE 802.1Q encapsulation of traffic on a specified subinterface in VLANs.
**encapsulation dot1q** *{vlan}*
34
# What is the Cisco IOS Command?
A subinterface subcommand that tells the router to use 802.1Q trunking, for a particular VLAN, and with the **native** keyword, to not encapsulate in a trunking header.
**encapsulation dot1q** *{vlan}* **[native]**
35
# What is the Cisco IOS Command?
A subinterface subcommand that tells the router to use ISL trunking for a particular VLAN.
**encapsulation isl** *{vlan}*
36
# What is the Cisco IOS Command?
Terminates configuration mode.
**end**
37
# What is the Cisco IOS Command?
Erases the startup configuration that is stored in nonvolatile memory.
**erase startup-config**
38
# What is the Cisco IOS Command?
Sets the interval before the user session is disconnected when idle.
**exec-timeout**
39
# What is the Cisco IOS Command?
Exits the current configuraton mode.
**exit**
40
# What is the Cisco IOS Command?
Sets the number of lines that are held in the history buffer for recall. Two separate buffers are used: one for EXEC mode commands and the other for configuration mode commands.
**history size** *{number}*
41
# What is the Cisco IOS Command?
From console or vty line configuration mode, sets the default number of commands saved in the history buffer for the user(s) of the console or vty lines, respetively.
**history size** *{number}*
42
# What is the Cisco IOS Command?
Sets the system name, which forms part of the prompt.
**hostname** *{**hostname}*
43
# What is the Cisco IOS Command?
Specifies an interface and enters interface configuration mode.
**interface** *{**type} {module/slot/port}*
44
# What is the Cisco IOS Command?
Enters interface configuration mode.
**interface** *{interface}*
45
# What is the Cisco IOS Command?
Enters the subinterface configuration mode.
**interface** *{interface}* **.** *{subinterface}*
46
# What is the Cisco IOS Command?
Global command to create a subinterface and to enter configuration mode for that subinterface.
**interface** *{interface}***.***{subinterface}*
47
# What is the Cisco IOS Command?
Specifies interface FastEthernet 0/13 and enters interface configuration mode.
**interface FastEthernet 0/13**
48
# What is the Cisco IOS Command?
Global command on a Layer 3 switch to create a VLAN interface and to enter configuration mode for that VLAN interface.
**interface vlan** *{vlan}*
49
# What is the Cisco IOS Command?
Enters interface configuration mode for VLAN 1 to set the switch management IP address.
**interface vlan 1**
50
# What is the Cisco IOS Command?
Applies an extended ACL to an interface in the inbound or outbound direction.
**ip access-group** *{acl\_name}* **[in | out]**
51
# What is the Cisco IOS Command?
Enables an IP ACL on an interface.
**ip access-group** *{ACL\_name}* **[in | out]**
52
# What is the Cisco IOS Command?
Defines an ACL and enters ACL configuration mode.
**ip access-list extended** *{ACL\_name}*
53
# What is the Cisco IOS Command?
Creates an extended, named ACL.
**ip access-list extended** *{acl\_name}*
54
# What is the Cisco IOS Command?
Configures an IP address manually on an interface.
**ip address** *{ip\_address} {network\_mask}*
55
# What is the Cisco IOS Command?
Sets the IP address and mask of the interface.
**ip address** *{ip-address} {subnet-mask}*
56
# What is the Cisco IOS Command?
Interface subcommand that assigns the interface's IP address and optionally makes the address a secondary address.
**ip address** *{ip-address} {mask}* **[secondary]**
57
# What is the Cisco IOS Command?
Configures an interface to obtain an IP address using DHCP.
**ip address dhcp**
58
# What is the Cisco IOS Command?
Specifies the IP addresses that a DHCP server should not assign to a DHCP client.
**ip dhcp excluded-addresses** *{ip-address}* [*{last-ip-address}*]
59
# What is the Cisco IOS Command?
Configures a DHCP address pool and enters DHCP configuration mode.
**ip dhcp pool** *{name}*
60
# What is the Cisco IOS Command?
Enables DNS resolution of symbolic names.
**ip domain lookup**
61
# What is the Cisco IOS Command?
Supplies an IP domain name that is required by the cryptographic key-generation process.
**ip domain-name** *{name}*
62
# What is the Cisco IOS Command?
Sets a domain name.
**ip domain-name** *{domain}*
63
# What is the Cisco IOS Command?
Enables forwarding of broadcasts that are received on the interface to the specified IP address.
**ip helper-address** *{address}*
64
# What is the Cisco IOS Command?
Configures an interface as NAT inside interface.
**ip nat inside**
65
# What is the Cisco IOS Command?
Configures an interface as NAT inside.
**ip nat inside**
66
# What is the Cisco IOS Command?
Configures a dynamic source NAT rule that translates addresses into IP addresses defined in the pool.
**ip nat inside source list** *{acl\_id}* **pool** *{pool\_name}*
67
# What is the Cisco IOS Command?
Configures dynamic NAT with PAT.
**ip nat inside source list** *{acl\_id}* **interface** *{interface}* **overload**
68
# What is the Cisco IOS Command?
Configures a dynaic source NAT or PAT rule that translates addresses into the IP address of an interface.
**ip nat inside source list** *{acl\_id}* **interface** *{interface\_name}* **overload**
69
# What is the Cisco IOS Command?
Configures an interface as NAT outside.
**ip nat outside**
70
# What is the Cisco IOS Command?
Configures an interface as a NAT outside interface.
**ip nat outside**
71
# What is the Cisco IOS Command?
Configures a NAT pool.
**ip nat pool** *{pool\_name} {start\_IP} {end\_IP}* **netmask** *{mask}*
72
# What is the Cisco IOS Command?
Global command that enables or disables the routing of IPv4 packets on a router or Layer 3 switch.
**[no] ip routing**
73
# What is the Cisco IOS Command?
Global configuration command that creates a static route.
**ip route** *{ip-address} {subnet-mask}* **[***{ip-address}* **|** *{interface}***]**
74
# What is the Cisco IOS Command?
Configures a static route (including a default route).
**ip route** *{network} {network\_mask} {next\_hop\_address}*
75
# What is the Cisco IOS Command?
Enables SSH version 2.
**ip ssh version 2**
76
# What is the Cisco IOS Command?
Specifies the version of SSH to be run. To disable the version of SSH that was configured and to return to compatibility mode, use the **no** form of this command.
**ip ssh version [1 | 2]**
77
# What is the Cisco IOS Command?
Global command that allows or disallows the configuration of an interface IP address in a zero subnet.
**[no] ip subnet-zero**
78
# What is the Cisco IOS Command?
Configures IPv6 address to the interface.
**ipv6 address** *{ipv6\_address}* **/** *{ipv6\_mask}*
79
# What is the Cisco IOS Command?
Sets the IPv6 address and prefix length on an interface.
**ipv6 address** *{ipv6-address}* **/** *{prefix\_length}*
80
# What is the Cisco IOS Command?
Enables IPv6 autoconfiguration on the interface.
**ipv6 address autoconfig**
81
# What is the Cisco IOS Command?
Enables an interface for OSPFv3 in an area.
**ipv6 ospf** *{process\_id}* **area** *{area\_id}*
82
# What is the Cisco IOS Command?
Enables OSPFv3 routing on the interface.
**ipv6 ospf** *{process\_ID}* **area** *{area\_ID}*
83
# What is the Cisco IOS Command?
Enables the IPv6 default route.
**ipv6 route ::/0** *{interface} {next\_hop}*
84
# What is the Cisco IOS Command?
Enables OSPFv3 and enters routing process mode.
**ipv6 router ospf** *{process\_ID}*
85
# What is the Cisco IOS Command?
Creates the OSPFv3 process.
**ipv6 router ospf** *{process\_id}*
86
# What is the Cisco IOS Command?
Enables IPv6 forwarding support on the router.
**ipv6 unicast-routing**
87
# What is the Cisco IOS Command?
Enables IPv6 routing on a router.
**ipv6 unicast-routing**
88
# What is the Cisco IOS Command?
Specifies the duration of the lease. The default is a one-day lease.
**lease** [*{days}* [*{hours}*] [*{minutes}*] | *{infinite}*]
89
# What is the Cisco IOS Command?
Enters line console configuration mode.
**line console 0**
90
# What is the Cisco IOS Command?
Enters vty configuration mode. Vty lines allow access to the switch for remote network management. The number of vty lines available is dependent on the Cisco IOS Software version. Typical values are 0-4 and 0-15 (inclusive).
**line vty** *{start\_number} {end\_number}*
91
# What is the Cisco IOS Command?
Synchronizes the display of router (or switch) output messages with the command-line prompt.
**logging synchronous**
92
# What is the Cisco IOS Command?
Synchronizes unsolicited messages and debugs privileged EXEC command output with solicited device output and prompts for a specific console port line or vty line.
**logging synchronous**
93
# What is the Cisco IOS Command?
Activates the login process on the console or vty lines.
**login**
94
# What is the Cisco IOS Command?
Enables verification of a password on a line.
**login**
95
# What is the Cisco IOS Command?
Enables verification of a username and password on a line.
**login local**
96
# What is the Cisco IOS Command?
Makes the login process on the console or vty lines rely on (or use) the local authentication database.
**login local**
97
# What is the Cisco IOS Command?
Exits EXEC mode and requires reauthentication (if enabled).
**logout**
98
# What is the Cisco IOS Command?
VLAN subcommand that names the VLAN.
**name** *{vlan-name}*
99
# What is the Cisco IOS Command?
Configures a router to advertise a network through OSPF.
**network** *{network} {wildcard\_mask}* **area** *{area\_id}*
100
# What is the Cisco IOS Command?
Defines addresses in the DHCP pool. Optionally, defines the subnet mask or prefix length. Either of these parameters determines which portion of the specified network number refers to the network part.
**network** *{network-number}* [*{mask}* | *{prefix-length}*]
101
# What is the Cisco IOS Command?
Router subcommand that enables OSPF on interfaces matching the address/wildcard combination and sets the OSPF area.
**network** *{ip-address} {wildcard-mask}* **area** *{area-id}*
102
# What is the Cisco IOS Command?
Disables Cisco Discovery Protocol on an interface.
**no cdp enable**
103
# What is the Cisco IOS Command?
Disables DNS resolution of symbolic names.
**no ip domain lookup**
104
# What is the Cisco IOS Command?
Disables the IPv6 default route.
**no ipv6 route ::/0** *{interface} {next\_hop}*
105
# What is the Cisco IOS Command?
OSPF subcommand that tells OSPF to be active (not passive) on that interface or subinterface.
**no passive-interface** *{interface}*
106
# What is the Cisco IOS Command?
Enables an interface.
**no shutdown**
107
# What is the Cisco IOS Command?
Global config command that has the same effect as the **[no] shutdown** VLAN mode subcommands.
**[no]** **shutdown vlan** *{vlan-id]*
108
# What is the Cisco IOS Command?
Configures Cisco IOS Software as an NTP master clock.
**ntp master** *{stratum}*
109
# What is the Cisco IOS Command?
Allows the software clock to be synchronized by an NTP time server.
**ntp server** *{ip-address}*
110
# What is the Cisco IOS Command?
OSPF subcommand that tells OSPF to be passive on that interface or subinterface.
**passive-interface** *{interface}*
111
# What is the Cisco IOS Command?
OSPF subcommand that changes the OSPF default for interfaces to be passive instead of active (not passive).
**passive-interface default**
112
# What is the Cisco IOS Command?
Assigns a password to the console or vty lines.
**password**
113
# What is the Cisco IOS Command?
Creates ACL statements for a named ACL. This one allows.
**permit** *{test conditions}*
114
# What is the Cisco IOS Command?
Creates a permit access list entry.
**permit [ip | tcp | udp]** *{source\_network} {wildcard} {mask} {dst\_network} {wildcard} {mask}*
115
# What is the Cisco IOS Command?
Uses ICMP echo requests and ICMP echo replies to determine whether a remote host is reachable.
**ping** *{ip-address}*
116
# What is the Cisco IOS Command?
Verifies connectivity between the source IP and destination IP.
**ping** *{dest\_IP}*
117
# What is the Cisco IOS Command?
Restarts the switch (or router) and reloads the Cisco IOS operating system and configuration.
**reload**
118
# What is the Cisco IOS Command?
Creates the OSPF process.
**router ospf** *{process\_id}*
119
# What is the Cisco IOS Command?
Starts the OSPF routing process with the specified process ID. The process ID is of local significance, so two routers can have different process IDs and still become neighbors.
**router ospf** *{process\_id}*
120
# What is the Cisco IOS Command?
Enters OSPF configuration mode for the listed process.
**router ospf** *{process-id}*
121
# What is the Cisco IOS Command?
Configures the OSPFv3 router ID. The router ID is a 32-bit value, written in the IPv4 form (x.x.x.x).
**router-id** *{router-id}*
122
# What is the Cisco IOS Command?
OSPF subcommand that statically sets the router ID.
**router-id** *{id}*
123
# What is the Cisco IOS Command?
A command on Cisco switches that enables the switch to support IP routing if configured.
**sdm prefer lanbase-routing**
124
125
# What is the Cisco IOS Command?
Displays all ACLs that are defined on the device.
**show access-list**
126
# What is the Cisco IOS Command?
Displays the contents of all IP ACLs.
**show access-lists** *{ACL\_name}*
127
# What is the Cisco IOS Command?
Displays global Cisco Discovery Protocol information.
**show cdp**
128
# What is the Cisco IOS Command?
States whether CDP is enabled globally, and lists the default update and holdtime timers.
**show cdp**
129
# What is the Cisco IOS Command?
Displays the same information as the **show cdp neighbors detail** command, but only for the named neighbor.
**show cdp entry** *{name}*
130
# What is the Cisco IOS Command?
States whether CDP is enabled on each interface, or a single interface if the interface is listed, and states update and holdtime timers on those interfaces.
**show cdp interface** **[***{interface}***]**
131
# What is the Cisco IOS Command?
Lists one summary line of information about each neighbor, or just the neighbor found on a specific interface if an interface was listed.
**show cdp neighbors [***{interface}***]**
132
# What is the Cisco IOS Command?
Displays detailed information about neighboring devices that are discovered by using Cisco Discovery Protocol.
**show cdp neighbors**
133
# What is the Cisco IOS Command?
Displays brief information about discovered neighboring Cisco devices. If the keyword **detail** is used, detailed information about discovered devices is displayed.
**show cdp neighbors [detail]**
134
# What is the Cisco IOS Command?
Lists one large set of information (approximately 15 lines) for every neighbor.
**show cdp neighbors detail**
135
# What is the Cisco IOS Command?
Displays global statistics for the number of CDP advertisements sent and received.
**show cdp traffic**
136
# What is the Cisco IOS Command?
Dipslays the system clock.
**show clock**
137
# What is the Cisco IOS Command?
Lists many lines of information per interface, or for one interface, for the hardware controller of the interface. On serial interfaces, this command identifies the cable as either a DCE or DTE cable.
**show controllers** *{interface}*
138
# What is the Cisco IOS Command?
Displays the layout and contents of a flash memory file system.
**show flash:**
139
# What is the Cisco IOS Command?
Examine most recently entered commands.
**show history**
140
# What is the Cisco IOS Command?
Lists the commands currently held in the history buffer.
**show history**
141
# What is the Cisco IOS Command?
Displays the switchport status of a port.
**show interfaces** *{interface}* **switchport**
142
# What is the Cisco IOS Command?
Displays statistics for all interfaces that are configured on the router (or switch).
**show interfaces**
143
# What is the Cisco IOS Command?
Displays information about all of the device interfaces.
**show interfaces**
144
# What is the Cisco IOS Command?
Displays the trunking status of a port.
**show interfaces** *{interface}* **trunk**
145
# What is the Cisco IOS Command?
Displays detailed information about interface status, settings, and counters.
**show interfaces** *{interface}*
146
# What is the Cisco IOS Command?
Displays one line of information per interface, with a two-item status (similar to the **show interfaces** command status), and includes any description that is configured on the interfaces.
**show interfaces description**
147
# What is the Cisco IOS Command?
Displays information about interface FastEthernet 0/13.
**show interfaces FastEthernet 0/13**
148
# What is the Cisco IOS Command?
Displays summary information about interface status and settings, including actual speed and duplex, a single-item status code, and whether the interface was autonegotiated.
**show interfaces** *{interface}* **status**
149
# What is the Cisco IOS Command?
Displays the status of interfaces.
**show interfaces status**
150
# What is the Cisco IOS Command?
Displays a large variety of configuration settings and current operational status, including VLAN trunking details, access and voice VLAN, and native VLAN.
**show interfaces** *{interface}* **switchport**
151
# What is the Cisco IOS Command?
Lists information about any interface regarding administrative settings and operational state.
**show interfaces** *{interface-id}* **switchport**
152
# What is the Cisco IOS Command?
Displays trunking information.
**show interfaces trunk**
153
# What is the Cisco IOS Command?
Lists information about the currently operational trunks (or just for the trunk listed in the command) and the VLANs supported on those trunks.
**show interfaces** *{interface}* **trunk**
154
# What is the Cisco IOS Command?
Lists information about all operational trunks (but no other interfaces), including the list of VLANs that can be forwarded over the trunk.
**show interfaces** *{interface-id}* **trunk**
155
# What is the Cisco IOS Command?
Displays configured access lists and hit counts.
**show ip access-lists**
156
# What is the Cisco IOS Command?
Displays a list of all DHCP address bindings.
**show ip dhcp binding**
157
# What is the Cisco IOS Command?
Displays IP-specific information for an interface, including the ACLs that are applied on an interface.
**show ip interface** *{interface-type} {interface number}*
158
# What is the Cisco IOS Command?
Dipslays the brief status and IP addresses of interfaces.
**show ip interface brief**
159
# What is the Cisco IOS Command?
Displays a brief summary of the interfaces on a device, which is useful for quickly checking the status of the device.
**show ip interface brief**
160
# What is the Cisco IOS Command?
Displays active NAT translations.
**show ip nat translations**
161
# What is the Cisco IOS Command?
Displays the NAT table.
**show ip nat translations**
162
# What is the Cisco IOS Command?
Lists a variety of facts about the local router's OSPF process, notably with the first line listing the router's router ID.
**show ip ospf**
163
# What is the Cisco IOS Command?
Lists a summary of the LSAs in the local router's LSDB, listing one line for each LSA.
**show ip ospf database**
164
# What is the Cisco IOS Command?
Displays interface information that is related to OSPF.
**show ip ospf interface**
165
# What is the Cisco IOS Command?
Lists a large group of messages per interface (or just for the one listed interface), with many facts: the area in which the interface resides, neighbors adjacent on this interface, and Hello and dead timers.
**show ip ospf interface** *{interface}*
166
# What is the Cisco IOS Command?
Lists one line per interface on which OSPF is enabled, for all interfaces (including passive interfaces) on which OSPF is enabled.
**show ip ospf interface brief**
167
# What is the Cisco IOS Command?
Shows all OSPF neighbors of the router.
**show ip ospf neighbor**
168
# What is the Cisco IOS Command?
Lists neighbors and current status with neighbors, per interface, and optionally lists details for the router ID listed in the command.
**show ip ospf neighbor** *{neighbor-RID}*
169
# What is the Cisco IOS Command?
Lists a group of messages for every instance of every routing protocol running in the router, restating many configuration parameters, default configuration settings when used, and listing the known OSPF routers in that area.
**show ip protocols**
170
# What is the Cisco IOS Command?
Lists the router's entire routing table.
**show ip route**
171
# What is the Cisco IOS Command?
Lists a subset of the IP routing table.
**show ip route [connected | static | ospf]**
172
# What is the Cisco IOS Command?
Displays the routing table.
**show ip route**
173
# What is the Cisco IOS Command?
Lists detailed information about the route that a router matches for the listed IP address.
**show ip route** *{ip-address}*
174
# What is the Cisco IOS Command?
Lists routes in the routing table learned by OSPF.
**show ip route [ospf]**
175
# What is the Cisco IOS Command?
Displays IPv6 settings and status on an interface.
**show ipv6 interface** *{interface}*
176
# What is the Cisco IOS Command?
Displays IPv6 status on the interface.
**show ipv6 interface** *{interface}*
177
# What is the Cisco IOS Command?
Displays the IPv6 neighbor discovery table.
**show ipv6 neighbors**
178
# What is the Cisco IOS Command?
Displays OSPFv3 settings.
**show ipv6 ospf**
179
# What is the Cisco IOS Command?
Displays OSPFv3 neighbors.
**show ipv6 ospf neighbor**
180
# What is the Cisco IOS Command?
Displays the IPv6 routing table.
**show ipv6 route**
181
# What is the Cisco IOS Command?
Displays the MAC address table on a switch.
**show mac address-table**
182
# What is the Cisco IOS Command?
Displays the MAC address table. The static option displays information about the restricted or static settings.
**show mac address-table [dynamic | static]** **[address** *{hw-addr}***] [interface** *{interface-id}***] [vlan** *{vlan-id}***]**
183
# What is the Cisco IOS Command?
Displays the status of NTP associations.
**show ntp associations**
184
# What is the Cisco IOS Command?
Displays the status of NTP.
**show ntp status**
185
# What is the Cisco IOS Command?
Displays information about security options configured on an interface.
**show port-security [interface** *{interface-id}***] [address]**
186
# What is the Cisco IOS Command?
Displays the secure MAC addresses for all ports.
**show port-security address**
187
# What is the Cisco IOS Command?
Displays the port security settings that are defined for an interface.
**show port-security interface** *{interface}*
188
# What is the Cisco IOS Command?
Lists information about the listed interface, including the IP address, mask, and line/protocol status.
**show protocols** *{interface}*
189
# What is the Cisco IOS Command?
Displays the active configuration (in RAM).
**show running-config**
190
# What is the Cisco IOS Command?
Examine the current configuration of a specific interface.
**show running-config interface** *{interface}*
191
# What is the Cisco IOS Command?
Dipslays the startup configuration settings that are saved in NVRAM.
**show startup-config**
192
# What is the Cisco IOS Command?
Displays the current settings for the terminal.
**show terminal**
193
# What is the Cisco IOS Command?
Displays information about the active lines on a router (or switch).
**show users**
194
# What is the Cisco IOS Command?
Displays users that are currently logged to a router.
**show users**
195
# What is the Cisco IOS Command?
Verify switch (and router) software and hardware status.
**show version**
196
# What is the Cisco IOS Command?
Displays the configuration of the switch (or router) hardware and the various software versions.
**show version**
197
# What is the Cisco IOS Command?
Lists information about the VLAN.
**show vlan [brief | id** *{vlan-id}* **| name** *{vlan-id}* **| summary]**
198
# What is the Cisco IOS Command?
Displays VLAN information.
**show vlan** *{vlan}*
199
# What is the Cisco IOS Command?
Lists each VLAN and all interfaces assigned to that VLAN but does not include trunks.
**show vlan [brief]**
200
# What is the Cisco IOS Command?
Displays VLAN information.
**show vlan**
201
# What is the Cisco IOS Command?
Lists both access and trunk ports in the VLAN.
**show vlan id** *{number}*
202
# What is the Cisco IOS Command?
When you configure a router on a stick, use this command to verify trunking and VLANs.
**show vlans**
203
# What is the Cisco IOS Command?
Lists VLAN configuration and statistics for VLAN trunks configured on routers.
**show vlans**
204
# What is the Cisco IOS Command?
Lists the current VTP status, including the current mode.
**show vtp status**
205
# What is the Cisco IOS Command?
Lists VTP configuration and status information.
**show vtp status**
206
# What is the Cisco IOS Command?
Shuts down an interface. Uses the **no** version of the command to enable the interface.
**shutdown**
207
# What is the Cisco IOS Command?
Disables an interface.
**shutdown**
208
# What is the Cisco IOS Command?
Interface subcommand that manually sets the interface speed.
**speed [auto | 10 | 100 | 1000]**
209
# What is the Cisco IOS Command?
Starts an encrypted session with a remote networking device using the current user ID. The IP address identifies the destination device.
**ssh -l username** *{ip\_address}*
210
# What is the Cisco IOS Command?
Interface subcommand that configures the trunking administrative mode on the interface.
**switchport mode [access | dynamic auto | dynamic desirable | trunk]**
211
# What is the Cisco IOS Command?
Assigns a port to a VLAN.
**switchport access vlan** *{vlan}*
212
# What is the Cisco IOS Command?
Specifies an access VLAN on a switchport.
**switchport access vlan** *{vlan}*
213
# What is the Cisco IOS Command?
Interface subcommand that statically configures the interface into that one VLAN.
**switchport access vlan** *{vlan-id}*
214
# What is the Cisco IOS Command?
Interface configuration mode command. There are four options. The two non-negotiating modes are trunk and switch, and the two DTP negotiation modes are dynamic auto and dynamic desirable.
**switchport mode** *{mode}*
215
# What is the Cisco IOS Command?
Configures a switchport as an access port.
**switchport mode access**
216
# What is the Cisco IOS Command?
Configures a switchport as a trunk.
**switchport mode trunk**
217
# What is the Cisco IOS Command?
Interface subcommand that disables the negotiation of VLAN trunking.
**switchport nonegotiate**
218
# What is the Cisco IOS Command?
Interface subcommand that tells the switch what to do if an inappropriate MAC address tries to access the network through a secure switch port.
**switchport port-security violation [protect | restrict | shutdown]**
219
# What is the Cisco IOS Command?
Enables the port security feature on the interface.
**switchport port-security**
220
# What is the Cisco IOS Command?
Enables port security on a switchport.
**switchport port-security**
221
# What is the Cisco IOS Command?
Manually defines MAC addresses that are allowed ona switchport when port security is enabled.
**switchport port-security mac-address** *{mac\_address}*
222
# What is the Cisco IOS Command?
Enters a secure MAC address for the interface.
**switchport port-security mac-address** *{mac-address}*
223
# What is the Cisco IOS Command?
Specifies the maximum number of MAC addresses that can be seen on a port when port security is enabled.
**switchport port-security maximum** *{number}*
224
# What is the Cisco IOS Command?
Configures the port security violation to protect.
**switchport port-security violation protect**
225
# What is the Cisco IOS Command?
Interface subcommand that defines the list of allowed VLANs.
**switchport trunk allowed vlan [add | all | except | remove]** *{vlan-list}*
226
# What is the Cisco IOS Command?
Specifies allowed VLANs on a trunk link.
**switchport trunk allowed vlan** *{vlans}*
227
# What is the Cisco IOS Command?
Specifies VLANS from which traffic is allowed over the trunk link.
**switchport trunk allowed vlan** *{vlan\_list}*
228
# What is the Cisco IOS Command?
Interface subcommand that defines which type of trunking to use, assuming that trunking is configured or negotiated.
**switchport trunk encapsulation [dot1q | isl | negotiate]**
229
# What is the Cisco IOS Command?
Interface subcommand that defines the antive VLAN for a trunk port.
**switchport trunk native vlan** *{vlan-id}*
230
# What is the Cisco IOS Command?
Establishes a Telnet session to an IP address.
**telnet** *{ip\_address}*
231
# What is the Cisco IOS Command?
Uses Telnet to connect to a destination IP address.
**telnet** *{ip\_address}*
232
# What is the Cisco IOS Command?
From EXEC mode, this command allows a single user to set, just for this one login session, the size of his or her history buffer.
**terminal history size** *{number}*
233
# What is the Cisco IOS Command?
Set the number of lines that are displayed without pause. Default is 24.
**terminal length** *{number}*
234
# What is the Cisco IOS Command?
Redirects debugging output to a Telnet session.
**terminal monitor**
235
# What is the Cisco IOS Command?
Traces to the specified IP address.
**traceroute** *{ip\_address}*
236
# What is the Cisco IOS Command?
Specifies which protocols to use to connect to a specific line of the device.
**transport input [telnet | ssh | all]**
237
# What is the Cisco IOS Command?
Allows Telnet and SSH on virtual lines.
**transport input ssh telnet**
238
# What is the Cisco IOS Command?
Disables all debugging.
**undebug all**
239
# What is the Cisco IOS Command?
Creates a user account in the local user database.
**username** *{username}* **password** *{password}*
240
# What is the Cisco IOS Command?
Creates a username and password pair that can then be used as a local authentication database.
**username** *{username}* **secret** *{password}*
241
# What is the Cisco IOS Command?
Global config command that both creates the VLAN and puts the CLI into VLAN configuration mode.
**vlan** *{vlan-id}*
242
# What is the Cisco IOS Command?
Creates the VLAN that is specified.
**vlan** *{vlan\_number}*
243
# What is the Cisco IOS Command?
Creates a VLAN on a switch.
**vlan** *{vlan\_id}*
244
# What is the Cisco IOS Command?
Global config command that defines the VTP mode.
**vtp mode [server | client | transparent | off]**
