面试题与答案

Troubleshooting network issues involves checking physical connections, verifying IP configurations, using network diagnostic tools, and examining logs. It follows a systematic approach to identify and resolve the problem.

Example:

For example, checking cables, verifying IP settings, and using tools like ping and traceroute to diagnose connectivity problems.

NAT reflection (or NAT hairpinning) is a technique where internal clients access a server on the local network using the external IP address of the router. The router reflects the connection back into the internal network.

Example:

When an internal user accesses a public server using the public IP address, NAT reflection allows the router to handle the request correctly.

A DDoS attack involves overwhelming a target system or network with a flood of traffic from multiple sources, rendering it unavailable to users. The goal is to disrupt normal functioning by exhausting resources such as bandwidth or server capacity.

Example:

In a DDoS attack, multiple compromised computers (botnets) might simultaneously send a massive amount of traffic to a website, causing it to become unreachable.

A DHCP relay agent is used to forward DHCP messages between devices on different IP subnets. It helps extend the reach of DHCP servers, allowing devices in remote subnets to obtain IP addresses and network configuration information.

Example:

In a large organization with multiple subnets, a DHCP relay agent forwards DHCP requests from remote subnets to a centralized DHCP server.