CISCO 4 Chapter 7

In an IPv6 address, the interface ID is used to identify a specific network interface. The interface ID is 64 bits long, which means that it requires 64 bits of the IPv6 address to uniquely identify the interface. Therefore, the correct answer is 64.

The given IPv6 prefix is 2001:0000:130F::/48. In IPv6, each hex digit represents 4 bits. Therefore, the prefix has a length of 48 * 4 = 192 bits. The organization is required to create subnetworks using this prefix. To determine the number of bits available for subnetworks, we subtract the length of the prefix from the total number of bits in an IPv6 address. An IPv6 address has a length of 128 bits. Therefore, the number of bits available for subnetworks is 128 - 192 = -64 bits. However, the number of available bits cannot be negative, so the correct answer is 16 bits.

The most likely incorrect part of the configuration is the access-list statement. This is because the access-list statement is responsible for defining which traffic should be translated by the NAT (Network Address Translation) process. If the access-list statement is incorrect or missing, the NAT process may not be applied to the desired traffic, causing the traffic exiting R1 to fail translation.

The given IP NAT pool statement specifies the range of IP addresses that can be assigned to traffic leaving S0. The statement "ip nat pool Tampa 179.9.8.96 179.9.8.111 netmask 255.255.255.240" indicates that the pool includes the IP addresses from 179.9.8.96 to 179.9.8.111, with a subnet mask of 255.255.255.240. Therefore, the two addresses that could be assigned to traffic leaving S0 are 179.9.8.98 and 179.9.8.101.

The supervisor has instructed the technician to always clear any dynamic translations before troubleshooting a failed NAT connection because entries can be cached for long periods of time. By clearing the translations, the supervisor wants to prevent decisions being made based on old data, ensuring that the troubleshooting process is based on the most up-to-date information.

In this topology, there are no IPv6 broadcast domains. A broadcast domain is a logical division of a computer network, where all devices can reach each other by broadcast at the data link layer. However, in IPv6, broadcast addresses are not used. Instead, multicast addresses are used to reach multiple devices. Therefore, there are no IPv6 broadcast domains in this topology.

The most likely problem is that the pool does not have a default router defined for the clients. This means that the DHCP clients are not being provided with the necessary information to access the Internet. Without a default router, the clients do not know where to send their network traffic.

Port Address Translation (PAT) is a type of Network Address Translation (NAT) that allows multiple devices on a private network to share a single public IP address. PAT uses unique source port numbers to distinguish between translations, which means that each device on the private network will have a different source port number assigned to it when communicating with the public network. This allows the router to keep track of which device the incoming packets belong to and properly forward the responses to the correct device.

A network administrator should use static NAT to ensure that a web server on the inside network is always available to the outside network. Static NAT maps a single private IP address to a single public IP address, allowing for consistent and permanent translation. This means that the web server will always have the same public IP address, making it easily accessible to the outside network.

The easiest solution to connect two IPv6 islands through a public network that only supports IPv4 equipment is to use tunneling. Tunneling involves encapsulating IPv6 traffic within the IPv4 protocol, allowing it to traverse the IPv4 network. This allows the IPv6 islands to communicate with each other by encapsulating the IPv6 packets within IPv4 packets, which can be understood by the IPv4 devices on the public network. This solution avoids the need to replace devices or configure RIPng or dual-stack technology.

The command marked with an arrow in the partial configuration output of a Cisco broadband router is used to define which addresses can be translated. This command specifies the range of IP addresses that can be translated using Network Address Translation (NAT). It allows the router to determine which addresses from the internal network can be translated to the external network, providing connectivity and security for the network.

NAT (Network Address Translation) provides two benefits. Firstly, it saves public IP addresses by allowing multiple devices on a private network to share a single public IP address. This conserves the limited pool of public IP addresses available. Secondly, NAT adds a degree of privacy and security to a network by hiding the internal IP addresses of devices from the external network. This helps to prevent direct access to devices on the internal network and adds a layer of protection against potential attacks.

According to the exhibit, the DHCP server has successfully assigned or renewed 8 addresses.

The valid destination IP address for HostA to put in its IP header when communicating with the web server would be 172.30.20.2. This is because R2 is performing NAT for the 192.168.1.2/24 network, and the web server is located on this network. Therefore, HostA needs to use the IP address of the web server (172.30.20.2) as the destination IP address in its IP header in order to communicate with it.

The NAT configuration in the exhibit is performing Port Address Translation (PAT), also known as NAT overload. This means that multiple internal IP addresses are being translated to a single external IP address. In this case, the address 172.16.1.1 is translated to an address from the pool beginning with 192.168.1.3. When a user on the outside network sees a request addressed from 192.168.1.3 using port 80, it means that the internal address 172.16.1.1 is being translated to 192.168.1.3 and the port number is also being translated to port 80.

The EUI-64 identifier configuration will derive the interface portion of the IPv6 address from the MAC address of the interface. This means that the last 64 bits of the IPv6 address will be based on the MAC address of the interface, providing a unique identifier for the interface. This allows for automatic address configuration without the need for manual assignment or DHCP.

The given configuration shows that the addresses in the pool of excluded addresses are statically assigned by the network administrator. This means that the network administrator manually assigns these addresses to key hosts on the network such as router interfaces, printers, and servers. The DHCP server does not dynamically assign these addresses, and they do not need to be listed under the DHCP pool of addresses for either static or dynamic assignment.

The inside global address refers to the IP address that is used on the outside network to represent the internal network. In this case, the inside global address is 209.165.20.25, as it is the IP address that is used to represent the internal network on the outside network.

To allow users on the Internet to connect to the FTP server on the Fa0/0 LAN of R1, the following configurations must be completed on R1:
1. Open port 20: Port 20 is used for FTP data transfer.
2. Open port 21: Port 21 is used for FTP control commands.
3. NAT with port forwarding: This is required to forward incoming FTP traffic from the Internet to the private IP address of the FTP server.

The correct answer is to enter the interface programming mode for each IPv6 interface and enable IPng RIP. This step is necessary to activate RIPng on the specific interfaces where IPv6 addresses have been programmed. By enabling IPng RIP on these interfaces, the router will start exchanging RIPng routing information with other routers in the network.

The first statement is true because the configuration includes the command "ip nat inside source list 1 pool NATPOOL overload", which specifies that traffic from the 10.1.1.0 network will be translated.
The third statement is also true because the configuration includes the command "ip nat inside source list 1 pool NATPOOL overload", which specifies that permitted traffic will be translated to a single inside global IP address.