NSClientServer#

A server that listens for incoming check_nt connection and processes incoming requests.

List of Configuration#

Common Keys#

Path / Section Key Description
/settings/default allowed hosts ALLOWED HOSTS
/settings/default bind to BIND TO ADDRESS
/settings/default cache allowed hosts CACHE ALLOWED HOSTS
/settings/default inbox INBOX
/settings/default password PASSWORD
/settings/default timeout TIMEOUT
/settings/NSClient/server performance data PERFORMANCE DATA
/settings/NSClient/server port PORT NUMBER
/settings/NSClient/server use ssl ENABLE SSL ENCRYPTION

Advanced keys#

Path / Section Key Description
/settings/default encoding NRPE PAYLOAD ENCODING
/settings/default socket queue size LISTEN QUEUE
/settings/default thread pool THREAD POOL
/settings/NSClient/server allowed ciphers ALLOWED CIPHERS
/settings/NSClient/server allowed hosts ALLOWED HOSTS
/settings/NSClient/server bind to BIND TO ADDRESS
/settings/NSClient/server ca CA
/settings/NSClient/server cache allowed hosts CACHE ALLOWED HOSTS
/settings/NSClient/server certificate SSL CERTIFICATE
/settings/NSClient/server certificate format CERTIFICATE FORMAT
/settings/NSClient/server certificate key SSL CERTIFICATE
/settings/NSClient/server dh DH KEY
/settings/NSClient/server password PASSWORD
/settings/NSClient/server socket queue size LISTEN QUEUE
/settings/NSClient/server ssl options VERIFY MODE
/settings/NSClient/server thread pool THREAD POOL
/settings/NSClient/server timeout TIMEOUT
/settings/NSClient/server verify mode VERIFY MODE

Configuration#

#

# 
[/settings/default]
allowed hosts=127.0.0.1
cache allowed hosts=true
inbox=inbox
socket queue size=0
thread pool=10
timeout=30
Key Default Value Description
allowed hosts 127.0.0.1 ALLOWED HOSTS
bind to BIND TO ADDRESS
cache allowed hosts true CACHE ALLOWED HOSTS
encoding NRPE PAYLOAD ENCODING
inbox inbox INBOX
password PASSWORD
socket queue size 0 LISTEN QUEUE
thread pool 10 THREAD POOL
timeout 30 TIMEOUT

allowed hosts#

ALLOWED HOSTS

A comma separated list of allowed hosts. You can use netmasks (/ syntax) or * to create ranges.

Key Description
Path: /settings/default
Key: allowed hosts
Default value: 127.0.0.1
Used by: CheckMKServer, NRPEServer, NSCAServer, NSClientServer, WEBServer

Sample#

[/settings/default]
# ALLOWED HOSTS
allowed hosts=127.0.0.1

bind to#

BIND TO ADDRESS

Allows you to bind server to a specific local address. This has to be a dotted ip address not a host name. Leaving this blank will bind to all available IP addresses.

Key Description
Path: /settings/default
Key: bind to
Default value: N/A
Used by: CheckMKServer, NRPEServer, NSCAServer, NSClientServer, WEBServer

Sample#

[/settings/default]
# BIND TO ADDRESS
bind to=

cache allowed hosts#

CACHE ALLOWED HOSTS

If host names (DNS entries) should be cached, improves speed and security somewhat but won’t allow you to have dynamic IPs for your Nagios server.

Key Description
Path: /settings/default
Key: cache allowed hosts
Default value: true
Used by: CheckMKServer, NRPEServer, NSCAServer, NSClientServer, WEBServer

Sample#

[/settings/default]
# CACHE ALLOWED HOSTS
cache allowed hosts=true

encoding#

NRPE PAYLOAD ENCODING

Key Description
Path: /settings/default
Key: encoding
Advanced: Yes (means it is not commonly used)
Default value: N/A
Used by: CheckMKServer, NRPEServer, NSCAServer, NSClientServer, WEBServer

Sample#

[/settings/default]
# NRPE PAYLOAD ENCODING
encoding=

inbox#

INBOX

The default channel to post incoming messages on

Key Description
Path: /settings/default
Key: inbox
Default value: inbox
Used by: CheckMKServer, NRPEServer, NSCAServer, NSClientServer, WEBServer

Sample#

[/settings/default]
# INBOX
inbox=inbox

password#

PASSWORD

Password used to authenticate against server

Key Description
Path: /settings/default
Key: password
Default value: N/A
Used by: CheckMKServer, NRPEServer, NSCAServer, NSClientServer, WEBServer

Sample#

[/settings/default]
# PASSWORD
password=

socket queue size#

LISTEN QUEUE

Number of sockets to queue before starting to refuse new incoming connections. This can be used to tweak the amount of simultaneous sockets that the server accepts.

Key Description
Path: /settings/default
Key: socket queue size
Advanced: Yes (means it is not commonly used)
Default value: 0
Used by: CheckMKServer, NRPEServer, NSCAServer, NSClientServer, WEBServer

Sample#

[/settings/default]
# LISTEN QUEUE
socket queue size=0

thread pool#

THREAD POOL

Key Description
Path: /settings/default
Key: thread pool
Advanced: Yes (means it is not commonly used)
Default value: 10
Used by: CheckMKServer, NRPEServer, NSCAServer, NSClientServer, WEBServer

Sample#

[/settings/default]
# THREAD POOL
thread pool=10

timeout#

TIMEOUT

Timeout when reading packets on incoming sockets. If the data has not arrived within this time we will bail out.

Key Description
Path: /settings/default
Key: timeout
Default value: 30
Used by: CheckMKServer, NRPEServer, NSCAServer, NSClientServer, WEBServer

Sample#

[/settings/default]
# TIMEOUT
timeout=30

NSCLIENT SERVER SECTION#

Section for NSClient (NSClientServer.dll) (check_nt) protocol options.

# Section for NSClient (NSClientServer.dll) (check_nt) protocol options.
[/settings/NSClient/server]
allowed ciphers=ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH
allowed hosts=127.0.0.1
ca=${certificate-path}/ca.pem
cache allowed hosts=true
certificate=${certificate-path}/certificate.pem
certificate format=PEM
dh=${certificate-path}/nrpe_dh_512.pem
performance data=true
port=12489
socket queue size=0
thread pool=10
timeout=30
use ssl=false
verify mode=none
Key Default Value Description
allowed ciphers ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH ALLOWED CIPHERS
allowed hosts 127.0.0.1 ALLOWED HOSTS
bind to BIND TO ADDRESS
ca ${certificate-path}/ca.pem CA
cache allowed hosts true CACHE ALLOWED HOSTS
certificate ${certificate-path}/certificate.pem SSL CERTIFICATE
certificate format PEM CERTIFICATE FORMAT
certificate key SSL CERTIFICATE
dh ${certificate-path}/nrpe_dh_512.pem DH KEY
password PASSWORD
performance data true PERFORMANCE DATA
port 12489 PORT NUMBER
socket queue size 0 LISTEN QUEUE
ssl options VERIFY MODE
thread pool 10 THREAD POOL
timeout 30 TIMEOUT
use ssl false ENABLE SSL ENCRYPTION
verify mode none VERIFY MODE

allowed ciphers#

ALLOWED CIPHERS

The chipers which are allowed to be used. The default here will differ is used in “insecure” mode or not. check_nrpe uses a very old chipers and should preferably not be used. For details of chipers please see the OPEN ssl documentation: https://www.openssl.org/docs/apps/ciphers.html

Key Description
Path: /settings/NSClient/server
Key: allowed ciphers
Advanced: Yes (means it is not commonly used)
Default value: ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# ALLOWED CIPHERS
allowed ciphers=ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH

allowed hosts#

ALLOWED HOSTS

A comma separated list of allowed hosts. You can use netmasks (/ syntax) or * to create ranges. parent for this key is found under: /settings/default this is marked as advanced in favor of the parent.

Key Description
Path: /settings/NSClient/server
Key: allowed hosts
Advanced: Yes (means it is not commonly used)
Default value: 127.0.0.1
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# ALLOWED HOSTS
allowed hosts=127.0.0.1

bind to#

BIND TO ADDRESS

Allows you to bind server to a specific local address. This has to be a dotted ip address not a host name. Leaving this blank will bind to all available IP addresses. parent for this key is found under: /settings/default this is marked as advanced in favor of the parent.

Key Description
Path: /settings/NSClient/server
Key: bind to
Advanced: Yes (means it is not commonly used)
Default value: N/A
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# BIND TO ADDRESS
bind to=

ca#

CA

Key Description
Path: /settings/NSClient/server
Key: ca
Advanced: Yes (means it is not commonly used)
Default value: ${certificate-path}/ca.pem
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# CA
ca=${certificate-path}/ca.pem

cache allowed hosts#

CACHE ALLOWED HOSTS

If host names (DNS entries) should be cached, improves speed and security somewhat but won’t allow you to have dynamic IPs for your Nagios server. parent for this key is found under: /settings/default this is marked as advanced in favor of the parent.

Key Description
Path: /settings/NSClient/server
Key: cache allowed hosts
Advanced: Yes (means it is not commonly used)
Default value: true
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# CACHE ALLOWED HOSTS
cache allowed hosts=true

certificate#

SSL CERTIFICATE

Key Description
Path: /settings/NSClient/server
Key: certificate
Advanced: Yes (means it is not commonly used)
Default value: ${certificate-path}/certificate.pem
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# SSL CERTIFICATE
certificate=${certificate-path}/certificate.pem

certificate format#

CERTIFICATE FORMAT

Key Description
Path: /settings/NSClient/server
Key: certificate format
Advanced: Yes (means it is not commonly used)
Default value: PEM
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# CERTIFICATE FORMAT
certificate format=PEM

certificate key#

SSL CERTIFICATE

Key Description
Path: /settings/NSClient/server
Key: certificate key
Advanced: Yes (means it is not commonly used)
Default value: N/A
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# SSL CERTIFICATE
certificate key=

dh#

DH KEY

Key Description
Path: /settings/NSClient/server
Key: dh
Advanced: Yes (means it is not commonly used)
Default value: ${certificate-path}/nrpe_dh_512.pem
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# DH KEY
dh=${certificate-path}/nrpe_dh_512.pem

password#

PASSWORD

Password used to authenticate against server parent for this key is found under: /settings/default this is marked as advanced in favor of the parent.

Key Description
Path: /settings/NSClient/server
Key: password
Advanced: Yes (means it is not commonly used)
Default value: N/A
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# PASSWORD
password=

performance data#

PERFORMANCE DATA

Send performance data back to Nagios (set this to 0 to remove all performance data).

Key Description
Path: /settings/NSClient/server
Key: performance data
Default value: true
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# PERFORMANCE DATA
performance data=true

port#

PORT NUMBER

Port to use for check_nt.

Key Description
Path: /settings/NSClient/server
Key: port
Default value: 12489
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# PORT NUMBER
port=12489

socket queue size#

LISTEN QUEUE

Number of sockets to queue before starting to refuse new incoming connections. This can be used to tweak the amount of simultaneous sockets that the server accepts. parent for this key is found under: /settings/default this is marked as advanced in favor of the parent.

Key Description
Path: /settings/NSClient/server
Key: socket queue size
Advanced: Yes (means it is not commonly used)
Default value: 0
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# LISTEN QUEUE
socket queue size=0

ssl options#

VERIFY MODE

Comma separated list of verification flags to set on the SSL socket.

default-workarounds Various workarounds for what I understand to be broken ssl implementations
no-sslv2 Do not use the SSLv2 protocol.
no-sslv3 Do not use the SSLv3 protocol.
no-tlsv1 Do not use the TLSv1 protocol.
single-dh-use Always create a new key when using temporary/ephemeral DH parameters. This option must be used to prevent small subgroup attacks, when the DH parameters were not generated using “strong” primes (e.g. when using DSA-parameters).
Key Description
Path: /settings/NSClient/server
Key: ssl options
Advanced: Yes (means it is not commonly used)
Default value: N/A
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# VERIFY MODE
ssl options=

thread pool#

THREAD POOL

parent for this key is found under: /settings/default this is marked as advanced in favor of the parent.

Key Description
Path: /settings/NSClient/server
Key: thread pool
Advanced: Yes (means it is not commonly used)
Default value: 10
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# THREAD POOL
thread pool=10

timeout#

TIMEOUT

Timeout when reading packets on incoming sockets. If the data has not arrived within this time we will bail out. parent for this key is found under: /settings/default this is marked as advanced in favor of the parent.

Key Description
Path: /settings/NSClient/server
Key: timeout
Advanced: Yes (means it is not commonly used)
Default value: 30
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# TIMEOUT
timeout=30

use ssl#

ENABLE SSL ENCRYPTION

This option controls if SSL should be enabled.

Key Description
Path: /settings/NSClient/server
Key: use ssl
Default value: false
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# ENABLE SSL ENCRYPTION
use ssl=false

verify mode#

VERIFY MODE

Comma separated list of verification flags to set on the SSL socket.

none The server will not send a client certificate request to the client, so the client will not send a certificate.
peer The server sends a client certificate request to the client and the certificate returned (if any) is checked.
fail-if-no-cert if the client did not return a certificate, the TLS/SSL handshake is immediately terminated. This flag must be used together with peer.
peer-cert Alias for peer and fail-if-no-cert.
workarounds Various bug workarounds.
single Always create a new key when using tmp_dh parameters.
client-once Only request a client certificate on the initial TLS/SSL handshake. This flag must be used together with verify-peer
Key Description
Path: /settings/NSClient/server
Key: verify mode
Advanced: Yes (means it is not commonly used)
Default value: none
Used by: NSClientServer

Sample#

[/settings/NSClient/server]
# VERIFY MODE
verify mode=none