CompTIA A+ Core 1 (220-1201)Hardware and Network TroubleshootingMedium
A technician is troubleshooting a client's workstation that experiences intermittent network connectivity. The user reports that sometimes they can access network resources, but other times they cannot, and their IP address occasionally changes. The technician checks the workstation's IP configuration and sees it is set to obtain an IP address automatically. Which of the following is the MOST likely cause?
- AA faulty network interface card (NIC).
- BIncorrect subnet mask configuration.
- CA duplicate IP address on the network.
- DAn expired DHCP lease.
Show answer & explanationAnswer & explanation
Correct answer: D. An expired DHCP lease.
Intermittent connectivity and an IP address that occasionally changes, especially when configured for DHCP, strongly suggest an issue with the DHCP lease. If the lease expires and the workstation cannot renew it, it might lose connectivity or obtain a new address.
Why the other options are wrong
- A. A faulty NIC would likely result in complete loss of connectivity or persistent errors, not intermittent connectivity with changing IP addresses.
- B. An incorrect subnet mask would generally cause consistent issues accessing resources outside its subnet, not intermittent connectivity and changing IP addresses.
- C. A duplicate IP address would typically cause a more consistent conflict or total loss of connectivity, not intermittent changes in the IP address itself.
DHCP Lease Expiration
When a client's dynamically assigned IP address lease from a DHCP server expires, and the client fails to renew it, leading to a loss of network connectivity or obtaining a new address.
- Clients periodically attempt to renew their DHCP leases.
- Failure to renew can cause intermittent connectivity.
- Symptoms include loss of IP address or obtaining a new one.
Memory trick: When the network connection comes and goes, and the IP address changes, think about the DHCP lease expiring and renewing.