A Linux administrator is troubleshooting a network connectivity issue between two servers, server-a and server-b, which are connected to the same physical switch. The administrator confirms that ping server-a from server-b fails.
The IP configurations are as follows:
server-a: inet 172.16.10.50/24 brd 172.16.10.255 scope global eth0
server-b: inet 172.16.10.100/26 brd 172.16.10.127 scope global eth0
What is the most likely reason for the connectivity failure?
A firewall on server-a is blocking ICMP requests.
The default gateway has not been configured on server-b.
server-b has an incorrect subnet mask, placing it on a different logical subnet.
server-b has the same IP address as another device on the network.
The correct answer is that server-b has an incorrect subnet mask, which places it on a different logical subnet from server-a.
server-a has an IP of 172.16.10.50 with a /24 mask (255.255.255.0). This places it on the 172.16.10.0 network, with a valid host range from 172.16.10.1 to 172.16.10.254. From server-a's perspective, server-b (172.16.10.100) is on its local network.
server-b has an IP of 172.16.10.100 with a /26 mask (255.255.255.192). This places it on the 172.16.10.64 network, with a valid host range from 172.16.10.65 to 172.16.10.126. From server-b's perspective, server-a (172.16.10.50) is on an external network.
Because of this mismatch, when server-b tries to contact server-a, it will send the packets to its default gateway instead of sending an ARP request on the local network. Communication fails because the two servers do not agree on the network boundaries.
A firewall could be the issue, but the fundamental configuration error in the subnet mask is a more direct and certain cause of the problem based on the provided data.
An IP conflict is not indicated, as the servers have unique IP addresses.
A default gateway is used for routing to different networks; communication within the same logical subnet does not require it.
Ask Bash
Bash is our AI bot, trained to help you pass your exam. AI Generated Content may display inaccurate information, always double-check anything important.
What is a subnet mask and why is it important?
Open an interactive chat with Bash
How does a `/24` subnet mask differ from a `/26` subnet mask?
Open an interactive chat with Bash
Why does a mismatched subnet mask send packets to the default gateway?
Open an interactive chat with Bash
CompTIA Linux+ XK0-006 (V8)
Troubleshooting
Your Score:
Report Issue
Bash, the Crucial Exams Chat Bot
AI Bot
Loading...
Loading...
Loading...
IT & Cybersecurity Package Join Premium for Full Access