Suppress Repeated Failed Clients
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Suppress Repeated Failed Clients
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Check this check box to suppress the clients for which the authentications fail repeatedly for the same reason. These clients
are suppressed from the audit logs and the requests from these clients are rejected for the specified time period if Reject RADIUS Requests from Clients with Repeated Failures option is enabled.
Note
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CTS related logs are not suppressed even if this option is enabled and are always included in the Live Logs.
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Detect Two Failures Within
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Enter the time interval in minutes. If a client fails authentication twice for the same reason within this time period, it
will be suppressed from the audit logs, and the requests from this client will be rejected if Reject RADIUS Requests from Clients with Repeated Failures option is enabled.
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Remember
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If the Suppress Repeated Failed Clients check box is checked and two failures occur within the time specified in the Detect Two Failures Within field, the endpoint is considered misconfigured. A misconfigured endpoint requires the admin’s intervention to ensure successful
authentication. When an endpoint fails the first authentication, the relevant information is displayed in the admin’s dashboard.
Subsequent authentication failures with the same reasons do not contain any added information for the admin. Therefore, repeated
authentication failures of an endpoint for a particular reason during the duration specified in the Report Failures Once Every field are not reported in the audit logs.
After the duration specified in the Report Failures Once Every field,the TotalFailedAttempts and TotalFailedTime information about the misconfigured endpoint is reported to the monitoring node.
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If the Suppress Repeated Failed Clients check box is checked and two failures occur after the time specified in the Detect Two Failures Within field, the failed authentication attempts of the endpoint will be reported in the audit logs as separate instances even if
the reason for the authentication failure remains the same.
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Cisco ISE allows the endpoint to conduct several consecutive failures with different failure reasons because endpoints can
have various supplicant profiles. Therefore, if the endpoint fails to authenticate several times because of different failure
reasons, Cisco ISE counts each failure reason separately.
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Report Failures Once Every
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Enter the time interval in minutes for the failed authentications to be reported. For example, if this value is set as 15
minutes, clients that repeatedly fail authentication will be reported in the audit logs only once every 15 minutes, thereby
preventing over-reporting.
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Reject RADIUS Requests from Clients with Repeated Failures
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Check this check box to automatically reject the RADIUS requests from the clients for which the authentications fail repeatedly.
You can enable this option to avoid unnecessary processing by Cisco ISE and to protect against potential denial of service
attacks.
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Remember
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If the Reject RADIUS Requests from Clients with Repeated Failures check box is checked and the endpoint experiences authentication failures equal to the number mentioned in the Failures Prior to Automatic Rejection field, the endpoint is considered misconfigured and is rejected. Cisco ISE will immediately reject the first RADIUS message
with the authentication request from this endpoint, thus, not allowing the endpoint to complete the authentication. No audit
logs will be generated for the endpoint. The endpoint stays rejected for the duration given in the Continue Rejecting Requests for field. The endpoint can send an authentication request after the duration specified in the Continue Rejecting Requests for, and if the authentication is successful, the endpoint will be configured.
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You can view and release the rejected endpoints on the Context Visibility () page. Select the rejected endpoints and click Release Rejected to release the rejected endpoints. The audit logs for the released endpoints will be sent to the monitoring node.
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If there is no activity from the misconfigured endpoint for a period of six hours, it will no longer be considered as misconfigured.
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Failures Prior to Automatic Rejection
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Enter the number of authentication failures after which requests from clients with repeated failures are automatically rejected.
All the requests received from these clients are automatically rejected for the configured time period (specified in Continue Rejecting Requests for field). After the interval expires, the authentication requests from these clients are processed.
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Continue Rejecting Requests for
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Enter the time interval (in minutes) for which the requests from clients with repeated failures are to be rejected.
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Ignore Repeated Accounting Updates Within
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Repeated accounting updates that occur within this period will be ignored.
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Suppress Successful Reports
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Suppress Repeated Successful Authentications
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Check this check box to prevent repeated reporting of successful authentication requests in last 24 hours that have no change
in identity context, network device, and authorization.
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Authentications Details
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Highlight Steps Longer Than
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Enter the time interval in milliseconds. If execution of a single step exceeds the specified threshold, it will be marked
with a clock icon in the authentication details page.
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Detect High Rate of RADIUS Requests
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Detect Steady High Rate of Radius Requests
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Check this check box to raise an alarm for high RADIUS request load when the limit specified in the Duration of RADIUS requests and Total number of RADIUS requests fields is exceeded.
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Duration of RADIUS Requests
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Enter the period of time (in seconds) that will be used to calculate the RADIUS rate. The default is 60 seconds. The valid
range is from 20 to 86400 seconds.
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Total Number of RADIUS Requests
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Enter the request limit that will be used to calculate the RADIUS rate. The default is 72000 requests. The valid range is
from 24000 to 103680000 requests.
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Identity Lock Settings
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Lock Identities with Repeated Authentication Failures
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Enable this option to protect against potential identity-based denial of service attacks. This limits the maximum number of
failed attempts an identity (username or hostname) can make, while authenticating through the EAP-TLS protocol. The username
or hostname of the identity is extracted from the Certificate Attribute field value in the Certificate Authentication Profile () and is used to track both authentication and authorization failures. You can specify the maximum number of failed authentication
attempts after which the identity will be locked. Identities can be locked permanently or for a specific time period. Following
an identity lock, further successful authentications will also be rejected until the identity is unlocked again.
Attention
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If an identity has Any Subject or Alternative Name Attributes in the Certificate as the field value for Use Identity From in its Certificate Authentication Profile, then it cannot be locked or unlocked using this option while authenticating through
EAP-TLS.
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Number of Retries
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Enter the number of authentication or authorization failures after which requests from identities are automatically rejected.
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Permanent Lock Type
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Choose this option to lock an identity permanently. To unlock permanently locked identities, choose the identity from the
Locked Identities table at the bottom of the page and click Unlock.
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Time Based Lock Type
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Choose this option to specify the time for which an identity must remain locked. Enter time in minutes. Identities will be
unlocked automatically after this period.
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Locked Identities
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This table lists the identities that are currrently locked along with their locked time, lockout type, and certificate IDs.
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RADIUS UDP Ports
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Authentication Ports
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Specify the ports to be used for RADIUS UDP authentication flows. You can specify a maximum of 4 port numbers (separated by
a comma). By default, port 1812 and port 1645 are used. The valid range is from 1024 to 65535.
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Accounting Ports
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Specify the ports to be used for RADIUS UDP accounting flows. You can specify a maximum of 4 port numbers (separated by a
comma). By default, port 1813 and port 1646 are used. The valid range is from 1024 to 65535.
Note
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Ensure that these ports are not used by other services.
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RADIUS DTLS
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Authentication and Accounting Port
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Specify the port to be used for RADIUS DTLS authentication and accounting flows. By default, port 2083 is used. The valid
range is from 1024 to 65535.
Note
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Ensure that this port is not used by other services.
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Idle Timeout
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Enter the time (in seconds) that you want Cisco ISE to wait before it closes the TLS session if no packets are received from
the network device. Default value is 120 seconds. The valid range is from 60 to 600 seconds.
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Enable RADIUS/DTLS Client Identity Verification
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Check this check box if you want Cisco ISE to verify the identity of the RADIUS/DTLS clients during the DTLS handshake. Cisco
ISE fails the handshake if the client identity is not valid. Identity check is skipped for the default network device, if
configured. Identity check is performed in the following sequence:
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If the client certificate contains the subject alternative name (SAN) attribute:
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If SAN contains the DNS name, the DNS name specified in the certificate is compared with the DNS name that is configured
for the network device in Cisco ISE.
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If SAN contains the IP address (and does not contain the DNS name), the IP address specified in the certificate is compared
with all the device IP addresses configured in Cisco ISE.
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If the certificate does not contain SAN, subject CN is compared with the DNS name that is configured for the network device
in Cisco ISE. Cisco ISE fails the handshake in the case of mismatch.
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