CCNA 2 v6 RSE CCENT (ICND1) Certification Exam Online

Interface VLAN 1 is a virtual interface on a switch, called SVI (switch virtual interface). Configuring an IP address on the default SVI, interface VLAN 1, will allow a switch to be accessed remotely. The VTY line must also be configured to allow remote access, but an IP address cannot be configured on this line.

Packets with a destination of 172.17.6.15 are forwarded through Fa0/0. Packets with a destination of 172.17.10.5 are forwarded through Fa1/1. Packets with a destination of 172.17.12.10 are forwarded through Fa1/0. Packets with a destination of 172.17.14.8 are forwarded through Fa0/1. Because network 172.17.8.0 has no entry in the routing table, it will take the gateway of last resort, which means that packets with a destination of 172.17.8.20 are forwarded through Serial0/0/0. Because a gateway of last resort exists, no packets will be dropped.

Switch S1 builds a MAC address table based on the source MAC address in the frame and the port upon which the frame enters the switch. The PC2 MAC address will be associated with port FA0/2. Because port FA0/1 of switch S1 connects with another switch, port FA0/1 will receive frames from multiple different devices. The MAC address table on switch S1 will therefore contain MAC addresses associated with each of the sending PCs.

A default static route is used as a gateway of last resort to forward unknown destination traffic to a next hop/exit interface. The next-hop or exit interface is the destination to send traffic to on a network after the traffic is matched in a router. The route source is the location a route was learned from.

If no violation mode is specified when port security is enabled on a switch port, then the security violation mode defaults to shutdown.

To forward all VLANs to the router, the switch interface Fa0/1 must be configured as a trunk interface with the switchport mode trunk command.

In an Ethernet network, a runt is a frame that is shorter than 64 bytes and a giant is a frame that is longer than the maximum allowed length. Both are often caused by NIC malfunctioning, but can also be caused by excessive collisions. CRC errors usually indicate a media or cable error caused by electrical interference, loose or damaged connections, or using the incorrect cabling type.

In most platforms running IOS 12.0 or later, Cisco Express Forwarding is enabled by default. Cisco Express Forwarding eliminates the need for the recursive lookup. If Cisco Express Forwarding is disabled, multiaccess network interfaces require fully specified static routes in order to avoid inconsistencies in their routing tables. Point-to-point interfaces do not have this problem, because multiple end points are not present. With or without Cisco Express Forwarding enabled, using an exit interface when configuring a static route is a viable option.

Interfaces that are configured as trunks do not belong to a VLAN and therefore will not show in the output of the show vlan brief commands.

IPv6 supports unicast, private, and multicast addresses but does not support Layer 3 broadcasts.

The voice VLAN should be configured with the switchport voice vlan 150 command. A switch interface can be configured to support one data VLAN and one voice VLAN. The mls qos trust cos associates with the interface. Voice traffic must be trusted so that fields within the voice packet can be used to classify it for QoS.

Members of different VLANs are on separate networks. For devices on separate networks to be able to communicate, a Layer 3 device, such as a router or Layer 3 switch, is necessary.

A /27 subnet contains 32 IP addresses, and a /30 subnet contains 4 IP addresses, so eight /30 subnets can be created from one /27 subnet.

The port on the switch that connects to the router interface should be configured as a trunk port. Once it becomes a trunk port, it does not belong to any particular VLAN and will forward traffic from various VLANs.

IPv4 subnets that require 100 and 80 hosts are provided by creating subnets of 126 usable addresses, each of which requires 7 host bits. The resulting mask is 255.255.255.128.
Subnets that require 30 and 20 hosts are provided by creating subnets of 30 usable addresses, each of which requires 5 host bits. The resulting mask is 255.255.255.224.
Creating nine subnets, each consisting of 126 usable addresses, would waste large numbers of addresses in the six smaller subnets.

The complete address range of the subnet with the host 10.10.247.1/21 is 10.10.240.0/21 to 10.10.247.255/21. The complete address range of the subnet that contains the host 10.10.248.10/24 is 10.10.248.0/24 to 10.10.248.255/24. This means that the next subnet will have a network address of 10.10.249.0 with a prefix length between 24 and 30. The first useable host address on this new subnet is therefore 10.10.249.1.

Link-local addresses are only unique on a given link, and the same address could exist out multiple interfaces. For that reason, any time a static route specifies a link-local address as the next hop, it must also specify the exit interface. This is called a fully specified static route.

Cisco License Manager (CLM) is available as a free download from the Cisco website and is a standalone application that helps network administrators deploy licenses across entire networks.

After the license is installed, the device needs to be reloaded to activate the license.

In order to identify the exact location of the desired configuration file, the IP address of the TFTP server and the name of the configuration file are essential information. Because the file is a new configuration, the name of the current configuration file is not necessary.

A frame is encapsulated with source and destination MAC addresses. The source device will not know the MAC address of the remote host. An ARP request will be sent by the source and will be responded to by the router. The router will respond with the MAC address of its interface, the one which is connected to the same network as the source.

If an interface that has been protected with port security goes into the err-disabled state, then a violation has occurred and the administrator should investigate the cause of the violation. Once the cause is determined, the administrator can issue the shutdown command followed by the no shutdown command to enable the interface.

From the output, the port F0/20 is not shown, which means it is configured as a trunk port. A native VLAN can only be assigned to a trunk port.

Layer 4 port numbers identify the application or service which will handle the data. The source port number is added by the sending device and will be the destination port number when the requested information is returned. Layer 4 segments are encapsulated within IP packets. UDP, not TCP, is used when low overhead is needed. A source IP address, not a TCP source port number, identifies the sending host on the network. Destination port numbers are specific ports that a server application or service monitors for requests.

UDP is a simple protocol that provides the basic transport layer functions. It has much lower overhead than TCP because it is not connection-oriented and does not offer the sophisticated retransmission, sequencing, and flow control mechanisms that provide reliability.

Because static routes must be created and changed manually, they require a larger investment of administrative time and do not scale easily. Static routes do not require additional CPU cycles to calculate and advertise routes, and they provide more security because they are not advertised over the network. Proper implementation of static routes requires the administrator to have a complete understanding of the network topology.

The show cdp neighbors detail command reveals much information about neighboring Cisco devices, including the IP address, the capabilities, host name, and IOS version. The show interfaces and show version commands display information about the local device.

In the display of show lldp neighbors command, the letter B represents a bridge. It also means a switch. The letter R represents a router. If a neighboring device is a WLAN access point, the letter W is used. Device A1 is connected to the port Fa0/1 on device B1. Device A1 is connected to the port Fa0/3 on device C1, and for that reason device C1 cannot connect to device B1 through the same port, Fa0/3.

The Carrier Sense Multiple Access/Collision Detection (CSMA/CD) process is a contention-based media access control mechanism used on shared media access networks, such as Ethernet. When a device needs to transmit data, it listens and waits until the media is available (quiet), then it will send data. If two devices transmit at the same time, a collision will occur. Both devices will detect the collision on the network. When a device detects a collision, it will stop the data transmission process, wait for a random amount of time, then try again.

The logging 192.168.1.5 command specifies the address of the syslog server where the messages are to be sent. The logging trap 3 command specifies that messages sent to the syslog server will be limited to severity levels of 3 and lower. The logging source-interface GigabitEthernet 0/1 command will set the source address of all syslog messages to be the address of interface GigabitEthernet 0/1.

A syslog server needs to be installed on a workstation in order to gather the messages that are sent from the managed network devices.

The factory setting for the configuration register is 0x2102. For password recovery, the administrator should perform this procedure:Step 1. Enter the ROMMON mode.
Step 2. Change the configuration register to 0x2142 to ignore the startup config file.
Step 3. Make necessary changes to the original startup config file.
Step 4. Save the new configuration.

The default-information originate command instructs the router to propagate the default static route to other routers by including that route in the routing updates.

The show ip dhcp binding command shows a list of IPv4 addresses and the MAC addresses of the hosts to which they are assigned. Using this information an administrator can determine which host interfaces have been assigned to specific hosts.

The ip helper-address command is used to configure a router to be a DHCPv4 relay. The command should be placed on the interface facing the DHCPv4 clients. When the command is applied on the router interface, the interface will receive DHCPv4 broadcast messages and forward them as unicast to the IP address of the DHCPv4 server.

The only filtering criteria specified for a standard access list is the source IPv4 address. The wild card mask is written to identify what parts of the address to match, with a 0 bit, and what parts of the address should be ignored, which a 1 bit. The router will parse the ACE entries from lowest sequence number to highest. If an ACE must be added to an existing access list, the sequence number should be specified so that the ACE is in the correct place during the ACL evaluation process.

The only filtering criteria specified for a standard access list is the source IPv4 address. The wild card mask is written to identify what parts of the address to match, with a 0 bit, and what parts of the address should be ignored, which a 1 bit.

Static NAT is a one-to-one mapping between an inside local address and an inside global address. By using static NAT, external devices can initiate connections to internal devices by using the inside global addresses. The NAT devices will translate the inside global address to the inside local address of the target host.

Dynamic NAT uses a pool of inside global addresses that are assigned to outgoing sessions. Creating the pool of inside global addresses is accomplished using the ip nat pool command.

A route will be installed in a routing table if there is not another routing source with a lower administrative distance. If a route with a lower administrative distance to the same destination network as a current route is entered, the route with the lower administrative distance will replace the route with a higher administrative distance.

A backup static route is called a floating static route. A floating static route has an administrative distance greater than the administrative distance of another static route or dynamic route.

A host route is an IPv6 route with a 128-bit mask. A host route can be installed in a routing table automatically when an IP address is configured on a router interface or manually if a static route is created.

The route ::/0 is the compressed form of the 0000:0000:0000:0000:0000:0000:0000:0000/0 default route. The default route is used if a more specific route is not found in the routing table.

Dynamic NAT uses a pool of inside global addresses that are assigned to outgoing sessions. If there are more internal hosts than public addresses in the pool, then an administrator can enable port address translation with the addition of the overload keyword. With port address translation, many internal hosts can share a single inside global address because the NAT device will track the individual sessions by Layer 4 port number.

The source address for packets forwarded by the router to the Internet will be the inside global address of 209.165.200.225. This is the address that the internal addresses from the 10.6.15.0 network will be translated to by NAT.

The application layer of the TCP/IP model maps to the top three layers of the OSI model, which are the application, presentation, and session layers.

Multicast IPv4 addresses use the reserved class D address range of 224.0.0.0 to 239.255.255.255.

IPv6 link-local unicast addresses are in the FE80::/10 prefix range and are not routable. They are used only for communications between devices on the same link.

IPv6 link-local unicast addresses are in the FE80::/10 prefix range and are not routable. They are used only for communications between devices on the same link.

The IPv6 specifications include anycast addresses. An anycast address is any unicast IPv6 address that is assigned to multiple devices.

With the show NTP associations command, the IP address of the NTP master is given.