What is the command to delete the default gateway from the system IP routing table? (Choose two correct answers.)

Anjali D.May 15, 2026

Our group landed on A and D as the two correct answers, and I think that is pretty clear once you see why the others fall apart. Route del default uses the legacy route command, which is part of the net-tools package, and it removes the default gateway entry directly from the kernel routing table. Ip route del default does the same thing using the newer iproute2 suite, which is the preferred tool on modern Linux systems, so you really should know both for the exam. The distractors are there to trip you up: ifconfig handles interface configuration, not routing; netstat -r just displays the routing table without modifying it; and sysctl is for reading or writing kernel parameters, not for deleting routing table entries. If you see a question asking you to remove or delete something from the routing table, your two tools are route and ip route, full stop, and that narrows it down to A and D every time. Anyone in the group unsure about when to use iproute2 versus net-tools? Worth discussing since the exam can test either one.

Hiroshi T.May 21, 2026

A and D are the correct picks. The route command from the net-tools package and the ip route command from iproute2 are both in scope for the 102-500 objective 4.4, and both accept the "del default" syntax to remove the default gateway entry from the kernel routing table. The distractor worth calling out is E, because sysctl does manage some net.ipv4 knobs, which makes it look plausible to someone who has only half-read the man page, but there is no sysctl key that removes a routing entry the way that option implies. C is a straightforward wrong answer since netstat -r only reads and displays the table, it never writes to it, and the exam has tested that read-vs-write distinction before.

Prof. SaraMay 6, 2026

Both A and B are correct because the Linux kernel routing table has two interfaces: the legacy "route" utility and the modern "ip route" command from the iproute2 package, and both use the keyword "del default" to remove the default gateway entry. A quick memory hook, RID, covers the three ip route actions you must know cold: Replace, Insert (add), Delete.