On a Linux workstation, the route command takes a long time before printing out the routing table. Which of the following errors does that indicate?

Question

Options

• AThe local routing information may be corrupted and must be re-validated using a routing protocol.
• BOne of the routers in the routing table is not available which causes the automatic router failure
• CThere may accidentally be more than one default router in which case a default router election
• DThe Linux Kernel Routing Daemon (LKRD) is not running and should be started using its init
• EDNS resolution may not be working as route by default tries to resolve names of routers and

• A
  15% (5)
• B
  6% (2)
• C
  3% (1)
• D
  6% (2)
• E
  71% (24)

Explanation

Option E is correct because the route command performs reverse DNS lookups by default, attempting to resolve each router's IP address to a hostname before displaying the table. When DNS is broken or unreachable, each lookup must wait for a timeout - often 30+ seconds per entry - making the command appear to hang. The fix is to run route -n (the -n flag forces numeric output, skipping DNS resolution entirely).

Why the distractors are wrong:

• A - The route command is a passive display tool; it doesn't trigger routing protocol re-validation. Corruption would cause errors, not delays.
• B - Displaying the routing table doesn't ping or probe routers, so an offline router has no effect on command speed.
• C - There is no "default router election" process initiated by running route; multiple default gateways just appear as duplicate entries.
• D - No such thing as a "Linux Kernel Routing Daemon (LKRD)" exists; Linux kernel routing is built-in and requires no separate daemon.

Memory tip: Associate the -n flag with "No DNS" - whenever a network command is suspiciously slow, try adding -n to skip name resolution. This applies to route -n, netstat -n, and similar tools.

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