|
Parameter |
Description |
|
Check Name: |
The user defined name of the health check. |
|
Method: |
The method for this health monitoring check. The methods may be
one of the following:
Ping:
The module sends an ICMP echo request to the destination address, via
the next hop (if defined), and waits for an echo reply. The module checks
that the reply was received from the same destination address that the
request was sent to, and that the sequence number is correct. POP3:The
module executes USER and PASS commands on the POP3 server. The module
checks that the returned code is +OK. Configurable
Parameters: Username and Password. RADIUS:
The module sends an Access Request with a user, password and a secret
string, and verifies that the request was accepted by the server which
then expects an Access Accept reply. Configurable
Parameters: Username, Password and Secret. RTSP:
The module executes a DESCRIBE command and expects a return status of
200. The user should configure the path on the server (like http) and
may specify a Hostname. SMTP:
The module executes a HELO command to the SMTP server and checks that
the returned code is 250. Configurable
Parameters: Server Name to use
in the HELO command. SNMP: An
SNMP Get request is sent to the destination IP address. The device then
verifies that a reply is received and that the returned value is within
a certain range.Configurable Parameters:
OID, Community,
Min. Value, Max. Value (Any return value, which is lower than the Min.
Value or higher than the Max. Value will be considered as a wrong value
and will cause the check to fail). SSL
Hello: The module sends an SSL Hello packet to the
server (using SSL3), and waits for an SSL Hello reply. The session is
then closed (using a RESET command). Configurable
parameters: SSL
Version, can be either v23 or v30. SSL v30 means pure SSLv3 is used, SSLv23
means that the client sends an SSLv2 request to open an SSLv3 session
(this is how Internet Explorer works, for example).
Note: It is recommended to use a timeout
of 3 to 5 seconds, as the server needs to generate SSL keys, which is
a time consuming process.
SSL:
This check enables you to perform an HTTP content check on Web servers
using SSL. The device performs an SSL handshake with the server and, once
the session is initiated, an HTTP Get request is performed. Configurable
parameters: Path to the server,
Hostname, HTTP Method ( GET,POST or HEAD), Username, Password, Match search
string (string to be matched), Match mode (String exists/String is absent),
HTTP return codes. TCP Port:
The module checks the availability of the specified TCP port. TCP User
Defined: Uses a User Defined TCP Health Check. Configurable
Parameters: Which user-defined
check to use (the Packet Sequence
number). UDP
Port: The module checks the availability of the specified UDP port.
Note that this check does not test the server's availability, but the
application's availability within the server. This is due to the nature
of UDP: when the UDP application is operational no reply is received,
while when the UDP application is not operational an ICMP message UDP
Port Unreachable is sent, so that the absence of a reply indicates the
application’s availability. This means that when the server is down, the
application might still be considered as running. Therefore UDP Port check
should always be used in a combination with another check for the server
availability, for example Ping or ARP. SIP UDP/TCP:
The SIP health check is done using the OPTIONS method. This method is
used to query SIP proxies and end-points as to their capabilities. The
capabilities themselves are not relevant to the health check and what
is relevant, is the “200 OK” response from the server. Configurable Parameters: Request URI:
The request destination. From:
The “logical name” of the device. Max Forwards:
Default 1 Transport
Protocol: The check can be performed on top of UDP (default) or
TCP. Destination
Port: Default is 5060. Acceptable
Response Codes: 200 is the default. When an unacceptable response
code is received – the check fails. Content Match: a content that must be matched
in the response for it to be considered successful. Reverse Match
Result: a content that must not be found in the response for it
to be successful. LDAPS: The
module performs a bind and unbind session with a LDAP server. The function
of the bind operation is to initiate a protocol session between a client
and a server, and to allow the authentication of the client to the server.
The function of the Unbind Operation is to terminate a protocol session.
The LDAP health check uses the proprietary LDAP UDP port number 389. Health Monitoring
Module allows to perform LDAP health checks over the SSL transport layer.
When using LDAP over SSL, the device uses the same SSL privet key as the
HTTPS health check, take from Health Monitoring global parameters. When
using the LDAPS checks, it is recommended to use values higher than 15
seconds for time interval and 10 seconds for timeout. Configurable
Parameters:
Password:
The password of the user. Base
Object: The location in the directory form which the LDAP search
begins. Attribute
Name: The attribute to for. For example CN - Common Name. Search
Value: The value to search. |
|
Dest IP: |
The destination IP address of the network server to be checked.
If no IP address is entered the default IP address is the Checked Element. |
|
Next Hop: |
The IP address of the next hop on the network for this check. This
is needed in order to direct the health check session to a network element's
MAC address. |
|
Dest Port: |
The destination's TCP\UDP port number. |
|
Arguments: |
The additional argument for the relevant health check method. The
possible arguments are based on the Method,
and may be one, or a combination of, the following:
The arguments are entered in the following
format: Argument1=value1| Argument2=Value2.
For example, the following is an argument for a FTP check: USER=JohnSmith|
PASS=ABC |
|
Interval: |
This interval defines the health check’s execution interval in seconds.
This field accepts only integers, and its value must be greater than the
timeout value. Maximum value is 2^32-1 seconds. |
|
Retries: |
This defines the number of times that a health check must fail before
the Health Monitoring module reevaluates the element’s availability status.
This field accepts only integers. |
|
Timeout: |
The is the maximum number of seconds that the device waits for a
response to the Health Check. This field accepts only integers. Maximum
value is 2^32-2 seconds. |
|
No New Session Timeout: |
The amount of time to pass, since initiating a check, till WSD recognizes
this element as heavily loaded and does not send any new sessions to it.
|
|
Measure Response Time: |
This parameter determines whether the response time of the check
is being used for load balancing decisions. This is applicable only when
Dispatch Method is set to Response Time LB. The Response Time is measured
in milliseconds. |
|
Reverse Check Result: |
The Reverse Check Result parameter indicates whether the check fails
when reply is received according to the check arguments or the check passes
when no reply received. The default is that the check fails when the server
does not reply. |
|
Response Level (read only): |
The Response Level is a normalized grade,
given to the check, based on the response times of each successful
check over the configured Response Level Sample rate and the configured
timeout.
Note: This parameter is displayed in the Update
window only when editing/updating a Check Table entry. |