Sets the parameters
for IP source validation. Source validation is useful if packet spoofing
is suspected or for verifying packet routing and labeling within
the network.
Source validation requires
the source address of received packets to match the IP address assigned
to the subscriber (either statically or dynamically) during the session.
Privilege:
Security Administrator,
Administrator
Syntax
ip source-violation { clear-on-valid-packet | drop-limit num | period secs }
no ip source-violation
clear-on-valid-packet
clear-on-valid-packet
Configures the service
to reset the drop-limit counters upon receipt of a properly addressed packet.
Default: disabled
drop-limit num
Sets the maximum number
of allowed IP source violations within the detection period before
dropping a call as an integer from 1 through 1000000. Default: 10
period secs
Sets the detection period
(in seconds) for IP source violations as an integer from 1 through 1000000.
Default: 120
Usage:
This function allows
the operator to configure the network to prevent problems such as when
a user gets handed back and forth between two gateways a number
of times during a handoff scenario.
When a subscriber packet
is received with a source IP address violation, the system increments
the IP source violation drop-limit counter and starts the timer
for the IP source violation period. Every subsequent packet received
with a bad source address during the IP source violation period
causes the drop-limit counter to increment.
For example, if the
drop-limit is set to 10, after 10 source violations, the call is
dropped. The detection period timer continues to count throughout
this process.
Example:
The following command
sets the drop limit to
15 and
leaves the other values at their default values:
ip source-violation
drop-limit 15