ICND1 | Interconnecting Cisco Networking Devices 1

In global configuration mode, the ip dhcp excluded-address ip-address |i [last-ip-address] specifies a single excluded IP address or range of addresses that a DHCP server should not assign to DHCP clients.

The address range command sets an address range for a DHCP server address pool. The ip dhcp excluded-address 10.1.50.1-25 command would not be the correct syntax to specify a range of IP addresses to exclude.

The network command can be used to define addresses in the DHCP pool, or define a subnet mask or prefix length to define the network part.

When the IP packet travels across the network topology as shown in the exhibit, it will be manipulated by the devices and changed based on the interfaces information. The layer 3 header is made up of the source and destination IP addresses, which do not change. However the source and destination MAC addresses in the layer 2 header will change.

When a packet leaves Router B, the source MAC address will be that of Fa0/0. Its source and destination IP address will be 10.3.3.2 and 10.2.2.2 respectively.

A MAC address is an Ethernet technology, therefore a serial port would not have a MAC address.
When the IP packet travels across the network topology as shown in the exhibit, it will be manipulated by the devices and changed based on the interfaces information. The layer 3 header is made up of the source and destination IP addresses, which do not change. However the source and destination MAC addresses in the layer 2 header will change.

When a packet leaves Router B, the source MAC address will be that of Fa0/0. Its source and destination IP address will be 10.3.3.2 and 10.2.2.2 respectively.

A MAC address is an Ethernet technology, therefore a serial port would not have a MAC address.
When the IP packet travels across the network topology as shown in the exhibit, it will be manipulated by the devices and changed based on the interfaces information. The layer 3 header is made up of the source and destination IP addresses, which do not change. However the source and destination MAC addresses in the layer 2 header will change.

When a packet leaves Router B, the source MAC address will be that of Fa0/0. Its source and destination IP address will be 10.3.3.2 and 10.2.2.2 respectively.

A MAC address is an Ethernet technology, therefore a serial port would not have a MAC address.

When you would like to restrict an incoming or outgoing connection between a particular VTY based on the IP address used by the device making the connection, use the access-class command in line configuration mode. The syntax for this command is:

access-class access-list-number

The ip access-group command allows you to apply an access list to an interface, and not a VTY line. The access-list command allows you to define an access list. The ip access-list command allows you to define an access list by name.
When you would like to restrict an incoming or outgoing connection between a particular VTY based on the IP address used by the device making the connection, use the access-class command in line configuration mode. The syntax for this command is:

access-class access-list-number

The ip access-group command allows you to apply an access list to an interface, and not a VTY line. The access-list command allows you to define an access list. The ip access-list command allows you to define an access list by name.
When you would like to restrict an incoming or outgoing connection between a particular VTY based on the IP address used by the device making the connection, use the access-class command in line configuration mode. The syntax for this command is:

access-class access-list-number

The ip access-group command allows you to apply an access list to an interface, and not a VTY line. The access-list command allows you to define an access list. The ip access-list command allows you to define an access list by name.

RIPv2 is one of the easiest routing protocols to configure, making it a good choice for small networks. However, RIPv2 still has limitations. RIPv2 has a route metric that is based only on hop count and is limited to 15 hops. To enter the router configuration mode for RIP, enter the router rip command at the global configuration prompt. The prompt changes to the router configuration prompt. To enable RIP routing for a network, use the network command in the router configuration mode. The network command assigns a major network number to which the router is directly connected. The RIP routing process associates interface addresses with the advertised network number and will begin RIP packet processing on the specified interfaces.

The network command enables RIP on all interfaces that belong to a specific network and advertises the specified networks. The networks 176.16.1.0 and 176.16.2.0 need to be advertised. The 176.16.2.0 is the local network associated with the 172.16.2.1 IP address on the S0/0/1 interface.
RIPv2 is one of the easiest routing protocols to configure, making it a good choice for small networks. However, RIPv2 still has limitations. RIPv2 has a route metric that is based only on hop count and is limited to 15 hops. To enter the router configuration mode for RIP, enter the router rip command at the global configuration prompt. The prompt changes to the router configuration prompt. To enable RIP routing for a network, use the network command in the router configuration mode. The network command assigns a major network number to which the router is directly connected. The RIP routing process associates interface addresses with the advertised network number and will begin RIP packet processing on the specified interfaces.

The network command enables RIP on all interfaces that belong to a specific network and advertises the specified networks. The networks 176.16.1.0 and 176.16.2.0 need to be advertised. The 176.16.2.0 is the local network associated with the 172.16.2.1 IP address on the S0/0/1 interface.
RIPv2 is one of the easiest routing protocols to configure, making it a good choice for small networks. However, RIPv2 still has limitations. RIPv2 has a route metric that is based only on hop count and is limited to 15 hops. To enter the router configuration mode for RIP, enter the router rip command at the global configuration prompt. The prompt changes to the router configuration prompt. To enable RIP routing for a network, use the network command in the router configuration mode. The network command assigns a major network number to which the router is directly connected. The RIP routing process associates interface addresses with the advertised network number and will begin RIP packet processing on the specified interfaces.

The network command enables RIP on all interfaces that belong to a specific network and advertises the specified networks. The networks 176.16.1.0 and 176.16.2.0 need to be advertised. The 176.16.2.0 is the local network associated with the 172.16.2.1 IP address on the S0/0/1 interface.

The three different types of IPv6 address are:

-Unicast
-Multicast
-Anycast

An IPv6 anycast address is assigned to an interface on more than one node. When a packet is sent to an anycast address, it is routed to the nearest interface that has this address. The nearest interface is found according to the measure of distance of the particular routing protocol. All nodes that share the same address should behave the same way so that the service is offered similarly regardless of the node that services the request.

Unicast addresses are used in a one-to-one context. In a unicast transmission, there is just one sender and one receiver. IPv6 has no support for broadcast addresses in the way that they are used in IPv4. Instead, specific multicast addresses (such as the all-nodes multicast address) are used.
The three different types of IPv6 address are:

-Unicast
-Multicast
-Anycast

An IPv6 anycast address is assigned to an interface on more than one node. When a packet is sent to an anycast address, it is routed to the nearest interface that has this address. The nearest interface is found according to the measure of distance of the particular routing protocol. All nodes that share the same address should behave the same way so that the service is offered similarly regardless of the node that services the request.

Unicast addresses are used in a one-to-one context. In a unicast transmission, there is just one sender and one receiver. IPv6 has no support for broadcast addresses in the way that they are used in IPv4. Instead, specific multicast addresses (such as the all-nodes multicast address) are used.
The three different types of IPv6 address are:

-Unicast
-Multicast
-Anycast

An IPv6 anycast address is assigned to an interface on more than one node. When a packet is sent to an anycast address, it is routed to the nearest interface that has this address. The nearest interface is found according to the measure of distance of the particular routing protocol. All nodes that share the same address should behave the same way so that the service is offered similarly regardless of the node that services the request.

Unicast addresses are used in a one-to-one context. In a unicast transmission, there is just one sender and one receiver. IPv6 has no support for broadcast addresses in the way that they are used in IPv4. Instead, specific multicast addresses (such as the all-nodes multicast address) are used.

The output of the show license udi command will reveal the router's unique device identifier (UDI). The UDI has two main components: the product ID (PID) and the serial number.

The show license command displays the licenses that are currently installed on a router. The show license feature command displays technology package licenses and feature licenses that are supported on the router. The show license statistics command displays license statistics information, such as the number of successful and failed license installations.
The output of the show license udi command will reveal the router's unique device identifier (UDI). The UDI has two main components: the product ID (PID) and the serial number.

The show license command displays the licenses that are currently installed on a router. The show license feature command displays technology package licenses and feature licenses that are supported on the router. The show license statistics command displays license statistics information, such as the number of successful and failed license installations.
The output of the show license udi command will reveal the router's unique device identifier (UDI). The UDI has two main components: the product ID (PID) and the serial number.

The show license command displays the licenses that are currently installed on a router. The show license feature command displays technology package licenses and feature licenses that are supported on the router. The show license statistics command displays license statistics information, such as the number of successful and failed license installations.

A class D or multicast addressing first octet range is 224 to 239. The entire range of multicast addresses goes from 224.0.0.0 through 239.255.255.255. A multicast address identifies a group of interfaces. Traffic that is sent to a multicast address is sent to multiple destinations at the same time. An interface may belong to any number of multicast groups.

There are 5 ranges of IP addresses in IPv4:

Class A - First octet range : 1 – 126
Class B - First octet range : 128 – 191
Class C - First octet range : 192 – 223
Class D - First octet range : 224 – 239 - Multicast addresses
Class E - First octet range : 240 – 254 - Experimental

The Class A range 127.0.0.0 to 127.255.255.255 is reserved for loopback and diagnostic functions.
A class D or multicast addressing first octet range is 224 to 239. The entire range of multicast addresses goes from 224.0.0.0 through 239.255.255.255. A multicast address identifies a group of interfaces. Traffic that is sent to a multicast address is sent to multiple destinations at the same time. An interface may belong to any number of multicast groups.

There are 5 ranges of IP addresses in IPv4:

Class A - First octet range : 1 – 126
Class B - First octet range : 128 – 191
Class C - First octet range : 192 – 223
Class D - First octet range : 224 – 239 - Multicast addresses
Class E - First octet range : 240 – 254 - Experimental

The Class A range 127.0.0.0 to 127.255.255.255 is reserved for loopback and diagnostic functions.
A class D or multicast addressing first octet range is 224 to 239. The entire range of multicast addresses goes from 224.0.0.0 through 239.255.255.255. A multicast address identifies a group of interfaces. Traffic that is sent to a multicast address is sent to multiple destinations at the same time. An interface may belong to any number of multicast groups.

There are 5 ranges of IP addresses in IPv4:

Class A - First octet range : 1 – 126
Class B - First octet range : 128 – 191
Class C - First octet range : 192 – 223
Class D - First octet range : 224 – 239 - Multicast addresses
Class E - First octet range : 240 – 254 - Experimental

The Class A range 127.0.0.0 to 127.255.255.255 is reserved for loopback and diagnostic functions.

The show ip route command displays the contents of the routing table in a router. The first part of the output explains the codes, presenting the letters and the associated sources of the entries in the routing table. The letter C is reserved for directly connected networks. 172.16.1.0/30 and 192.168.1.0/24 are both directly connected routes. A directly connected route is a route directly connected to one of the router's interfaces. The administrative distance of a directly connected route is 0.
The show ip route command displays the contents of the routing table in a router. The first part of the output explains the codes, presenting the letters and the associated sources of the entries in the routing table. The letter C is reserved for directly connected networks. 172.16.1.0/30 and The show ip route command displays the contents of the routing table in a router. The first part of the output explains the codes, presenting the letters and the associated sources of the entries in the routing table. The letter C is reserved for directly connected networks. 172.16.1.0/30 and 192.168.1.0/24 are both directly connected routes. A directly connected route is a route directly connected to one of the router's interfaces. The administrative distance of a directly connected route is 0.
The show ip route command displays the contents of the routing table in a router. The first part of the output explains the codes, presenting the letters and the associated sources of the entries in the routing table. The letter C is reserved for directly connected networks. 172.16.1.0/30 and 192.168.1.0/24 are both directly connected routes. A directly connected route is a route directly connected to one of the router's interfaces. The administrative distance of a directly connected route is 0.

The login local command has been entered in line configuration mode. This means that user credentials are stored in a local database. Unless the username command was used to credential some local accounts, no one will be able to connect to the device remotely.

If only the login command was issued, then a password would need to be configured on the lines. Although it is a good idea to secure traffic with SSH, it is not required. Configuring SSH would not fix the problem presented in this scenario.
The login local command has been entered in line configuration mode. This means that user credentials are stored in a local database. Unless the username command was used to credential some local accounts, no one will be able to connect to the device remotely.

If only the login command was issued, then a password would need to be configured on the lines. Although it is a good idea to secure traffic with SSH, it is not required. Configuring SSH would not fix the problem presented in this scenario.
The login local command has been entered in line configuration mode. This means that user credentials are stored in a local database. Unless the username command was used to credential some local accounts, no one will be able to connect to the device remotely.

If only the login command was issued, then a password would need to be configured on the lines. Although it is a good idea to secure traffic with SSH, it is not required. Configuring SSH would not fix the problem presented in this scenario.

For a trunk link to be established, both ends of the trunk link must be configured to use the same native VLAN. Cisco Discovery Protocol (CDP) will present a native VLAN mismatch error message if the native VLANs do not match. To display the status of the trunk and the native VLAN used on that trunk link, and to verify trunk establishment, you can use the show interface trunk command in privileged EXEC mode.

Cisco Discovery Protocol (CDP) exchanges hardware and software device information with its directly connected CDP neighbors. Although this is a useful troubleshooting tool, it would not prevent hosts from communicating with each other. Dynamic Trunking Protocol (DTP) is a Cisco proprietary protocol used to manage automatic trunk negotiation. Disabling DTP would create further issues, as the trunk link would be disabled. Disabling RSTP would not prevent hosts from communicating with each other unless there was a loop involved.
For a trunk link to be established, both ends of the trunk link must be configured to use the same native VLAN. Cisco Discovery Protocol (CDP) will present a native VLAN mismatch error message if the native VLANs do not match. To display the status of the trunk and the native VLAN used on that trunk link, and to verify trunk establishment, you can use the show interface trunk command in privileged EXEC mode.

Cisco Discovery Protocol (CDP) exchanges hardware and software device information with its directly connected CDP neighbors. Although this is a useful troubleshooting tool, it would not prevent hosts from communicating with each other. Dynamic Trunking Protocol (DTP) is a Cisco proprietary protocol used to manage automatic trunk negotiation. Disabling DTP would create further issues, as the trunk link would be disabled. Disabling RSTP would not prevent hosts from communicating with each other unless there was a loop involved.
For a trunk link to be established, both ends of the trunk link must be configured to use the same native VLAN. Cisco Discovery Protocol (CDP) will present a native VLAN mismatch error message if the native VLANs do not match. To display the status of the trunk and the native VLAN used on that trunk link, and to verify trunk establishment, you can use the show interface trunk command in privileged EXEC mode.

Cisco Discovery Protocol (CDP) exchanges hardware and software device information with its directly connected CDP neighbors. Although this is a useful troubleshooting tool, it would not prevent hosts from communicating with each other. Dynamic Trunking Protocol (DTP) is a Cisco proprietary protocol used to manage automatic trunk negotiation. Disabling DTP would create further issues, as the trunk link would be disabled. Disabling RSTP would not prevent hosts from communicating with each other unless there was a loop involved.

This configuration example demonstrates a dynamic Network Address Translation (NAT) configuration. Dynamic NAT maps an unregistered IPv4 address to a registered IPv4 address from a pool of registered IPv4 addresses (many-to-many). The example translates all source addresses that pass Access Control List (ACL) 1, which means a source address from the 192.168.1.0/24 network, into an address from the pool named net-208. The net-208 pool contains addresses from 171.69.233.209/28 to 171.69.233.222/28.

Because the "overload" keyword is missing from the command-line output PAT and NAT can be excluded as being possible correct options. Static NAT is a mapping of an unregistered IPv4 address to a registered IPv4 address on a one-to-one basis that does not involve an address pool as indicated in the output.
This configuration example demonstrates a dynamic Network Address Translation (NAT) configuration. Dynamic NAT maps an unregistered IPv4 address to a registered IPv4 address from a pool of registered IPv4 addresses (many-to-many). The example translates all source addresses that pass Access Control List (ACL) 1, which means a source address from the 192.168.1.0/24 network, into an address from the pool named net-208. The net-208 pool contains addresses from 171.69.233.209/28 to 171.69.233.222/28.

Because the "overload" keyword is missing from the command-line output PAT and NAT can be excluded as being possible correct options. Static NAT is a mapping of an unregistered IPv4 address to a registered IPv4 address on a one-to-one basis that does not involve an address pool as indicated in the output.
This configuration example demonstrates a dynamic Network Address Translation (NAT) configuration. Dynamic NAT maps an unregistered IPv4 address to a registered IPv4 address from a pool of registered IPv4 addresses (many-to-many). The example translates all source addresses that pass Access Control List (ACL) 1, which means a source address from the 192.168.1.0/24 network, into an address from the pool named net-208. The net-208 pool contains addresses from 171.69.233.209/28 to 171.69.233.222/28.

Because the "overload" keyword is missing from the command-line output PAT and NAT can be excluded as being possible correct options. Static NAT is a mapping of an unregistered IPv4 address to a registered IPv4 address on a one-to-one basis that does not involve an address pool as indicated in the output.

One of the most common configuration errors is when one trunk port is configured with trunk mode "off" and the other with trunk mode "on". This configuration error causes the trunk link to stop working. Cisco Catalyst switch ports run Dynamic Trunking Protocol (DTP) by default, which tries to automatically negotiate a trunk link. This can result in a trunk mismatch if DTP is not able to negotiate a trunk link. As such, trunk links should be configured statically whenever possible to avoid potential trunk mode mismatches from DTP.

The native VLAN that is configured on each end of an IEEE 802.1Q trunk must be the same or the trunk link will not work. If one end of the trunk is configured for native VLAN 1 and the other end is configured for native VLAN 2, a frame sent from VLAN1 on one side will be received on VLAN2 on the other side. VLAN 1 "leaks" into the VLAN 2 segment. Such a configuration error generates console notifications, causes control and management traffic misdirection, and poses a security risk.
One of the most common configuration errors is when one trunk port is configured with trunk mode "off" and the other with trunk mode "on". This configuration error causes the trunk link to stop working. Cisco Catalyst switch ports run Dynamic Trunking Protocol (DTP) by default, which tries to automatically negotiate a trunk link. This can result in a trunk mismatch if DTP is not able to negotiate a trunk link. As such, trunk links should be configured statically whenever possible to avoid potential trunk mode mismatches from DTP.

The native VLAN that is configured on each end of an IEEE 802.1Q trunk must be the same or the trunk link will not work. If one end of the trunk is configured for native VLAN 1 and the other end is configured for native VLAN 2, a frame sent from VLAN1 on one side will be received on VLAN2 on the other side. VLAN 1 "leaks" into the VLAN 2 segment. Such a configuration error generates console notifications, causes control and management traffic misdirection, and poses a security risk.
One of the most common configuration errors is when one trunk port is configured with trunk mode "off" and the other with trunk mode "on". This configuration error causes the trunk link to stop working. Cisco Catalyst switch ports run Dynamic Trunking Protocol (DTP) by default, which tries to automatically negotiate a trunk link. This can result in a trunk mismatch if DTP is not able to negotiate a trunk link. As such, trunk links should be configured statically whenever possible to avoid potential trunk mode mismatches from DTP.

The native VLAN that is configured on each end of an IEEE 802.1Q trunk must be the same or the trunk link will not work. If one end of the trunk is configured for native VLAN 1 and the other end is configured for native VLAN 2, a frame sent from VLAN1 on one side will be received on VLAN2 on the other side. VLAN 1 "leaks" into the VLAN 2 segment. Such a configuration error generates console notifications, causes control and management traffic misdirection, and poses a security risk.

You use the clock summer-time command to allow a Cisco device to automatically switch to summer time. Summer time is also known as daylight saving time.

To disable automatic switching to summer time, you can use the following command:

no clock summer-time

By default, summer time is disabled. This command is performed in the Global configuration mode.

The clock timezone command allows you to set the time zone for the Cisco device. The clock read-calendar command configures the software clock to set its date and time by the hardware clock setting. The clock update-calendar command performs a one-time update of the hardware clock from the software clock.

Static Network Address Translation (NAT) is manually configured. It maps an unregistered IPv4 address to a registered IPv4 address (one-to-one).

For more information on the commands you would need to enter to create a static address translation, please refer to the |h %5coutput%5ct14%5cmisc%5c100105eo418a.html additional explanation.

DNS was created for domain name-to-address resolution for networks. DNS uses a set of servers to resolve the names that are associated with numbered addresses. The DNS protocol defines an automated service that matches resource names with the required numeric network address. This also works with hosts on an internal network connecting to hosts on the Internet.

SSH and Telnet are protocols used to establish a connection with remote devices over a network without needing to convert readable names to IP addresses. SSH is widely used over Telnet as SSH encrypts its data.

CDP is a Cisco proprietary protocol that discovers basic information about neighboring Cisco devices without needing to know the passwords for the neighboring devices and does not convert readable names to IP addresses.
DNS was created for domain name-to-address resolution for networks. DNS uses a set of servers to resolve the names that are associated with numbered addresses. The DNS protocol defines an automated service that matches resource names with the required numeric network address. This also works with hosts on an internal network connecting to hosts on the Internet.

SSH and Telnet are protocols used to establish a connection with remote devices over a network without needing to convert readable names to IP addresses. SSH is widely used over Telnet as SSH encrypts its data.

CDP is a Cisco proprietary protocol that discovers basic information about neighboring Cisco devices without needing to know the passwords for the neighboring devices and does not convert readable names to IP addresses.
DNS was created for domain name-to-address resolution for networks. DNS uses a set of servers to resolve the names that are associated with numbered addresses. The DNS protocol defines an automated service that matches resource names with the required numeric network address. This also works with hosts on an internal network connecting to hosts on the Internet.

SSH and Telnet are protocols used to establish a connection with remote devices over a network without needing to convert readable names to IP addresses. SSH is widely used over Telnet as SSH encrypts its data.

CDP is a Cisco proprietary protocol that discovers basic information about neighboring Cisco devices without needing to know the passwords for the neighboring devices and does not convert readable names to IP addresses.