LPI 102-500 Exam With Confidence Using Practice Dumps

The connection types, as seen in nmcli connection show, are the types of network configurations that Network Manager can manage. They are not the same as the network protocols or layers, such as TCP or IPv6, but rather the logical or physical ways of connecting to a network. According to the Network Manager reference manual1, some of the possible connection types are:

wifi: This connection type is for wireless network interfaces that use the IEEE 802.11 standard. It requires a wifi device and a wifi access point to establish a connection. The connection settings include the SSID, security, password, etc.

bridge: This connection type is for creating a network bridge, which is a device that connects two or more network segments and forwards packets between them. It requires a bridge device and one or more slave devices to be attached to the bridge. The connection settings include the bridge name, MAC address, STP, etc.

vpn: This connection type is for creating a virtual private network, which is a secure tunnel between two or more network endpoints. It requires a VPN plugin and a VPN service provider to establish a connection. The connection settings include the VPN type, service name, user name, password, etc.

The other options are not correct because:

tcp: This is not a connection type, but a network protocol that operates at the transport layer. It provides reliable, ordered, and error-checked delivery of data between applications. It is not a configuration option for Network Manager.

Ethernet: This is not a connection type, but a network technology that operates at the physical and data link layers. It defines the standards for wiring, signaling, and framing of data packets. It is not a configuration option for Network Manager, but rather a device type that can be used by other connection types, such as bridge or vpn.

ipv6: This is not a connection type, but a network protocol that operates at the network layer. It provides addressing and routing of data packets across networks. It is not a configuration option for Network Manager, but rather an IP configuration option that can be used by other connection types, such as wifi or vpn. References:

The correct SQL query to count the number of occurrences for each value of the field order_type in the table orders is:

SELECT order_type,COUNT(*) FROM orders GROUP BY order_type;

This query uses the SELECT statement to retrieve the values of the order_type field and the COUNT(*) function to count the number of rows for each order_type. The GROUP BY clause groups the rows by the order_type field, so that the count is calculated for each distinct value of order_type. The result of this query is a table with two columns: order_type and count, where each row shows the number of orders for a specific order_type.

The other options are incorrect for the following reasons:

A: This query uses a WHERE clause that is always true, since order_type=order_type for every row. Therefore, this query returns the same result as SELECT order_type,COUNT(*) FROM orders;, which is a table with one row that shows the total number of orders, regardless of the order_type.

C: This query is syntactically invalid, since the COUNT function cannot take a subquery as an argument. The correct way to use a subquery with COUNT is COUNT((SELECT order_type FROM orders));, which returns the total number of orders, regardless of the order_type.

D: This query uses the ORDER BY clause to sort the rows by the order_type field, but it does not group them by order_type. Therefore, this query returns the same result as SELECT COUNT(*) FROM orders;, which is a table with one row that shows the total number of orders, regardless of the order_type.

E: This query is syntactically invalid, since there is no such function as AUTO_COUNT in SQL, and the COUNT function cannot take a field name as an argument. The correct way to use COUNT with a field name is COUNT(order_type);, which returns the number of non-null values in the order_type field.

References:

[SQL COUNT Function]

[SQL GROUP BY Statement]

[SQL SELECT Statement]

The routing table shows how the kernel will route packets to different destinations based on the destination IP address, the gateway, the netmask, the flags, the metric, and the interface. The kernel will try to find the most specific route that matches the destination IP address, which means the route with the longest netmask. If there are multiple routes with the same netmask, the kernel will use the route with the lowest metric. If there is no matching route, the kernel will use the default route, which is the route with the destination 0.0.0.0.

In this case, the destination IP address is 192.168.2.150, which belongs to the network 192.168.2.0/24. The routing table has a specific route for this network, which is the second entry. The gateway for this route is 0.0.0.0, which means that the packet will be directly transmitted on the interface eth0, without passing through any router. The netmask for this route is 255.255.255.0, which means that the network has 256 possible hosts. The flags for this route are U, which means that the route is up, and G, which means that the route is to a gateway. The metric for this route is 0, which means that it has the highest priority. Therefore, the kernel will use this route to handle the outgoing packet to the destination 192.168.2.150.

References:

How To Display Routing Table In Linux - RootUsers

route command in Linux with Examples - GeeksforGeeks

Understand the basics of Linux routing | TechRepublic