unconditional-src-learn
Syntax
unconditional-src-learn;
Hierarchy Level
[edit interfaces interface-name unit logical-unit-number family inet]
Description
Enables the router to learn IP addresses from nonvalidated sources when proxy Address Resolution Protocol (ARP) is configured.
By default, the router learns IP addresses from validated sources only. When this statement is configured and proxy ARP is enabled on an unnumbered interface, the router responds to ARP requests from any IP address, which might lead to exploitable information disclosure. An attacker can poison the ARP cache and create a fake forwarding table entry for an IP address, effectively creating a denial of service for that subscriber or interface. Therefore, exercise caution when configuring this statement.
Required Privilege Level
interface—To view this statement in the configuration.
interface-control—To add this statement to the configuration.
Release Information
Statement introduced in Junos OS Release 10.4R16.