CHECK_NRPE: Receive header underflow - only 0 bytes received

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Re: CHECK_NRPE: Receive header underflow - only 0 bytes rece

Postby cocoyanouck » Wed Jun 27, 2018 2:47 am

Code: Select all
allowed_hosts=127.0.0.1,::1,10.0.2.130


Code: Select all
root@Nagios-VZ:/etc/nagios# /etc/init.d/nagios-nrpe-server start
[ ok ] Starting nagios-nrpe-server (via systemctl): nagios-nrpe-server.service.


Code: Select all
root@Nagios-VZ:/usr/lib/nagios/plugins# ./check_nrpe -H 10.0.2.130
CHECK_NRPE: Error - Could not connect to 10.0.2.130: Connection reset by peer


Port 5666 is not blocked, moreover, this module is working on my other nagios-server.

:(

For information, here is the configuration of the another server whick is running since 4 years.

Code: Select all
root@nagios-debian:/home/nagios# cat /etc/nagios/nrpe.cfg
#############################################################################
#
#  Sample NRPE Config File
#
#  Notes:
#
#  This is a sample configuration file for the NRPE daemon.  It needs to be
#  located on the remote host that is running the NRPE daemon, not the host
#  from which the check_nrpe client is being executed.
#
#############################################################################


# LOG FACILITY
# The syslog facility that should be used for logging purposes.

log_facility=daemon



# LOG FILE
# If a log file is specified in this option, nrpe will write to
# that file instead of using syslog.

#log_file=/var/log/nrpe.log



# DEBUGGING OPTION
# This option determines whether or not debugging messages are logged to the
# syslog facility.
# Values: 0=debugging off, 1=debugging on

debug=0



# PID FILE
# The name of the file in which the NRPE daemon should write it's process ID
# number.  The file is only written if the NRPE daemon is started by the root
# user and is running in standalone mode.

pid_file=/var/run/nagios/nrpe.pid



# PORT NUMBER
# Port number we should wait for connections on.
# NOTE: This must be a non-privileged port (i.e. > 1024).
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

server_port=5666



# SERVER ADDRESS
# Address that nrpe should bind to in case there are more than one interface
# and you do not want nrpe to bind on all interfaces.
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

#server_address=127.0.0.1



# LISTEN QUEUE SIZE
# Listen queue size (backlog) for serving incoming connections.
# You may want to increase this value under high load.

#listen_queue_size=5



# NRPE USER
# This determines the effective user that the NRPE daemon should run as.
# You can either supply a username or a UID.
#
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

nrpe_user=nagios



# NRPE GROUP
# This determines the effective group that the NRPE daemon should run as.
# You can either supply a group name or a GID.
#
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

nrpe_group=nagios



# ALLOWED HOST ADDRESSES
# This is an optional comma-delimited list of IP address or hostnames
# that are allowed to talk to the NRPE daemon. Network addresses with a bit mask
# (i.e. 192.168.1.0/24) are also supported. Hostname wildcards are not currently
# supported.
#
# Note: The daemon only does rudimentary checking of the client's IP
# address.  I would highly recommend adding entries in your /etc/hosts.allow
# file to allow only the specified host to connect to the port
# you are running this daemon on.
#
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

allowed_hosts=127.0.0.1,::1



# COMMAND ARGUMENT PROCESSING
# This option determines whether or not the NRPE daemon will allow clients
# to specify arguments to commands that are executed.  This option only works
# if the daemon was configured with the --enable-command-args configure script
# option.
#
# *** ENABLING THIS OPTION IS A SECURITY RISK! ***
# Read the SECURITY file for information on some of the security implications
# of enabling this variable.
#
# Values: 0=do not allow arguments, 1=allow command arguments

dont_blame_nrpe=0



# BASH COMMAND SUBSTITUTION
# This option determines whether or not the NRPE daemon will allow clients
# to specify arguments that contain bash command substitutions of the form
# $(...).  This option only works if the daemon was configured with both
# the --enable-command-args and --enable-bash-command-substitution configure
# script options.
#
# *** ENABLING THIS OPTION IS A HIGH SECURITY RISK! ***
# Read the SECURITY file for information on some of the security implications
# of enabling this variable.
#
# Values: 0=do not allow bash command substitutions,
#         1=allow bash command substitutions

allow_bash_command_substitution=0



# COMMAND PREFIX
# This option allows you to prefix all commands with a user-defined string.
# A space is automatically added between the specified prefix string and the
# command line from the command definition.
#
# *** THIS EXAMPLE MAY POSE A POTENTIAL SECURITY RISK, SO USE WITH CAUTION! ***
# Usage scenario:
# Execute restricted commmands using sudo.  For this to work, you need to add
# the nagios user to your /etc/sudoers.  An example entry for allowing
# execution of the plugins from might be:
#
# nagios          ALL=(ALL) NOPASSWD: /usr/lib/nagios/plugins/
#
# This lets the nagios user run all commands in that directory (and only them)
# without asking for a password.  If you do this, make sure you don't give
# random users write access to that directory or its contents!

# command_prefix=/usr/bin/sudo


# MAX COMMANDS
# This specifies how many children processes may be spawned at any one
# time, essentially limiting the fork()s that occur.
# Default (0) is set to unlimited
# max_commands=0



# COMMAND TIMEOUT
# This specifies the maximum number of seconds that the NRPE daemon will
# allow plugins to finish executing before killing them off.

command_timeout=60



# CONNECTION TIMEOUT
# This specifies the maximum number of seconds that the NRPE daemon will
# wait for a connection to be established before exiting. This is sometimes
# seen where a network problem stops the SSL being established even though
# all network sessions are connected. This causes the nrpe daemons to
# accumulate, eating system resources. Do not set this too low.

connection_timeout=300



# WEAK RANDOM SEED OPTION
# This directive allows you to use SSL even if your system does not have
# a /dev/random or /dev/urandom (on purpose or because the necessary patches
# were not applied). The random number generator will be seeded from a file
# which is either a file pointed to by the environment valiable $RANDFILE
# or $HOME/.rnd. If neither exists, the pseudo random number generator will
# be initialized and a warning will be issued.
# Values: 0=only seed from /dev/[u]random, 1=also seed from weak randomness

#allow_weak_random_seed=1



# SSL/TLS OPTIONS
# These directives allow you to specify how to use SSL/TLS.

# SSL VERSION
# This can be any of: SSLv2 (only use SSLv2), SSLv2+ (use any version),
#        SSLv3 (only use SSLv3), SSLv3+ (use SSLv3 or above), TLSv1 (only use
#        TLSv1), TLSv1+ (use TLSv1 or above), TLSv1.1 (only use TLSv1.1),
#        TLSv1.1+ (use TLSv1.1 or above), TLSv1.2 (only use TLSv1.2),
#        TLSv1.2+ (use TLSv1.2 or above)
# If an "or above" version is used, the best will be negotiated. So if both
# ends are able to do TLSv1.2 and use specify SSLv2, you will get TLSv1.2.
# If you are using openssl 1.1.0 or above, the SSLv2 options are not available.

#ssl_version=SSLv2+

# SSL USE ADH
# This is for backward compatibility and is DEPRECATED. Set to 1 to enable
# ADH or 2 to require ADH. 1 is currently the default but will be changed
# in a later version.

#ssl_use_adh=1

# SSL CIPHER LIST
# This lists which ciphers can be used. For backward compatibility, this
# defaults to 'ssl_cipher_list=ALL:!MD5:@STRENGTH' for < OpenSSL 1.1.0,
# and 'ssl_cipher_list=ALL:!MD5:@STRENGTH:@SECLEVEL=0' for OpenSSL 1.1.0 and
# greater.

#ssl_cipher_list=ALL:!MD5:@STRENGTH
#ssl_cipher_list=ALL:!MD5:@STRENGTH:@SECLEVEL=0
#ssl_cipher_list=ALL:!aNULL:!eNULL:!SSLv2:!LOW:!EXP:!RC4:!MD5:@STRENGTH

# SSL Certificate and Private Key Files

#ssl_cacert_file=/etc/ssl/servercerts/ca-cert.pem
#ssl_cert_file=/etc/ssl/servercerts/nagios-cert.pem
#ssl_privatekey_file=/etc/ssl/servercerts/nagios-key.pem

# SSL USE CLIENT CERTS
# This options determines client certificate usage.
# Values: 0 = Don't ask for or require client certificates (default)
#         1 = Ask for client certificates
#         2 = Require client certificates

#ssl_client_certs=0

# SSL LOGGING
# This option determines which SSL messages are send to syslog. OR values
# together to specify multiple options.

# Values: 0x00 (0)  = No additional logging (default)
#         0x01 (1)  = Log startup SSL/TLS parameters
#         0x02 (2)  = Log remote IP address
#         0x04 (4)  = Log SSL/TLS version of connections
#         0x08 (8)  = Log which cipher is being used for the connection
#         0x10 (16) = Log if client has a certificate
#         0x20 (32) = Log details of client's certificate if it has one
#         -1 or 0xff or 0x2f = All of the above

#ssl_logging=0x00



# NASTY METACHARACTERS
# This option allows you to override the list of characters that cannot
# be passed to the NRPE daemon.

# nasty_metachars="|`&><'\\[]{};\r\n"



# COMMAND DEFINITIONS
# Command definitions that this daemon will run.  Definitions
# are in the following format:
#
# command[<command_name>]=<command_line>
#
# When the daemon receives a request to return the results of <command_name>
# it will execute the command specified by the <command_line> argument.
#
# Unlike Nagios, the command line cannot contain macros - it must be
# typed exactly as it should be executed.
#
# Note: Any plugins that are used in the command lines must reside
# on the machine that this daemon is running on!  The examples below
# assume that you have plugins installed in a /usr/local/nagios/libexec
# directory.  Also note that you will have to modify the definitions below
# to match the argument format the plugins expect.  Remember, these are
# examples only!


# The following examples use hardcoded command arguments...
# This is by far the most secure method of using NRPE

command[check_users]=/usr/lib/nagios/plugins/check_users -w 5 -c 10
command[check_load]=/usr/lib/nagios/plugins/check_load -r -w .15,.10,.05 -c .30,.25,.20
command[check_hda1]=/usr/lib/nagios/plugins/check_disk -w 20% -c 10% -p /dev/hda1
command[check_zombie_procs]=/usr/lib/nagios/plugins/check_procs -w 5 -c 10 -s Z
command[check_total_procs]=/usr/lib/nagios/plugins/check_procs -w 150 -c 200


# The following examples allow user-supplied arguments and can
# only be used if the NRPE daemon was compiled with support for
# command arguments *AND* the dont_blame_nrpe directive in this
# config file is set to '1'.  This poses a potential security risk, so
# make sure you read the SECURITY file before doing this.

### MISC SYSTEM METRICS ###
#command[check_users]=/usr/lib/nagios/plugins/check_users $ARG1$
#command[check_load]=/usr/lib/nagios/plugins/check_load $ARG1$
#command[check_disk]=/usr/lib/nagios/plugins/check_disk $ARG1$
#command[check_swap]=/usr/lib/nagios/plugins/check_swap $ARG1$
#command[check_cpu_stats]=/usr/lib/nagios/plugins/check_cpu_stats.sh $ARG1$
#command[check_mem]=/usr/lib/nagios/plugins/custom_check_mem -n $ARG1$

### GENERIC SERVICES ###
#command[check_init_service]=sudo /usr/lib/nagios/plugins/check_init_service $ARG1$
#command[check_services]=/usr/lib/nagios/plugins/check_services -p $ARG1$

### SYSTEM UPDATES ###
#command[check_yum]=/usr/lib/nagios/plugins/check_yum
#command[check_apt]=/usr/lib/nagios/plugins/check_apt

### PROCESSES ###
#command[check_all_procs]=/usr/lib/nagios/plugins/custom_check_procs
#command[check_procs]=/usr/lib/nagios/plugins/check_procs $ARG1$

### OPEN FILES ###
#command[check_open_files]=/usr/lib/nagios/plugins/check_open_files.pl $ARG1$

### NETWORK CONNECTIONS ###
#command[check_netstat]=/usr/lib/nagios/plugins/check_netstat.pl -p $ARG1$ $ARG2$

### ASTERISK ###
#command[check_asterisk]=/usr/lib/nagios/plugins/check_asterisk.pl $ARG1$
#command[check_sip]=/usr/lib/nagios/plugins/check_sip $ARG1$
#command[check_asterisk_sip_peers]=sudo /usr/lib/nagios/plugins/check_asterisk_sip_peers.sh $ARG1$
#command[check_asterisk_version]=/usr/lib/nagios/plugins/nagisk.pl -c version
#command[check_asterisk_peers]=/usr/lib/nagios/plugins/nagisk.pl -c peers
#command[check_asterisk_channels]=/usr/lib/nagios/plugins/nagisk.pl -c channels
#command[check_asterisk_zaptel]=/usr/lib/nagios/plugins/nagisk.pl -c zaptel
#command[check_asterisk_span]=/usr/lib/nagios/plugins/nagisk.pl -c span -s 1



# INCLUDE CONFIG FILE
# This directive allows you to include definitions from an external config file.

#include=<somefile.cfg>



# INCLUDE CONFIG DIRECTORY
# This directive allows you to include definitions from config files (with a
# .cfg extension) in one or more directories (with recursion).

#include_dir=<somedirectory>
#include_dir=<someotherdirectory>



# local configuration:
# if you'd prefer, you can instead place directives here

include=/etc/nagios/nrpe_local.cfg

# you can place your config snipplets into nrpe.d/
# only snipplets ending in .cfg will get included

include_dir=/etc/nagios/nrpe.d/


Code: Select all
root@nagios-debian:/usr/lib/nagios/plugins# ./check_nrpe -H localhost
NRPE v3.2.1
cocoyanouck
 
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Re: CHECK_NRPE: Receive header underflow - only 0 bytes rece

Postby scottwilkerson » Wed Jun 27, 2018 7:06 am

What is the IP of Nagios-VZ ?

this is what should be added to the allowed_hosts
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Re: CHECK_NRPE: Receive header underflow - only 0 bytes rece

Postby cocoyanouck » Wed Jun 27, 2018 3:00 pm

IP of nagios-vz is 10.0.2.130, so it's in allowed-host of this server : allowed_hosts=127.0.0.1,::1,10.0.2.130
cocoyanouck
 
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Re: CHECK_NRPE: Receive header underflow - only 0 bytes rece

Postby scottwilkerson » Wed Jun 27, 2018 3:50 pm

If this works
Code: Select all
root@nagios-debian:/usr/lib/nagios/plugins# ./check_nrpe -H localhost
NRPE v3.2.1


And this doesn't
Code: Select all
root@Nagios-VZ:/usr/lib/nagios/plugins# ./check_nrpe -H 10.0.2.130
CHECK_NRPE: Error - Could not connect to 10.0.2.130: Connection reset by peer


There are only a few possibilities, one, a firewall is blocking, or 2 incompatible versions of ./check_nrpe

What does this output
Code: Select all
root@Nagios-VZ:/usr/lib/nagios/plugins# ./check_nrpe -h|head -8
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Re: CHECK_NRPE: Receive header underflow - only 0 bytes rece

Postby cocoyanouck » Fri Jun 29, 2018 3:12 am

Result is :
Code: Select all
NRPE Plugin for Nagios
Copyright (c) 1999-2008 Ethan Galstad (nagios@nagios.org)
Version: 3.0.1
Last Modified: 09-08-2016
License: GPL v2 with exemptions (-l for more info)
SSL/TLS Available: OpenSSL 0.9.6 or higher required


On our first nagios server :

Code: Select all
nagios@nagios-debian:/usr/lib/nagios/plugins$ ./check_nrpe -H localhost
NRPE v3.2.1
nagios@nagios-debian:/usr/lib/nagios/plugins$ ./check_nrpe -H 10.0.2.201
CHECK_NRPE: Error - Could not connect to 10.0.2.201: Connection reset by peer


But it seems normal because
Code: Select all
allowed_hosts=127.0.0.1,::1


On the new nagios-vz i want to introduce, same result for this two entries :

Code: Select all
root@Nagios-VZ:/usr/lib/nagios/plugins# ./check_nrpe -H localhost
CHECK_NRPE: Error - Could not connect to ::4c3a:433a:4b3a:413a: Connection reset by peer
root@Nagios-VZ:/usr/lib/nagios/plugins# ./check_nrpe -H 10.0.2.130
CHECK_NRPE: Error - Could not connect to 10.0.2.130: Connection reset by peer


Code: Select all
allowed_hosts=127.0.0.1,::1,10.0.2.130
cocoyanouck
 
Posts: 90
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Re: CHECK_NRPE: Receive header underflow - only 0 bytes rece

Postby scottwilkerson » Fri Jun 29, 2018 7:47 am

so this is an issue
Code: Select all
root@Nagios-VZ:/usr/lib/nagios/plugins# ./check_nrpe -H localhost
CHECK_NRPE: Error - Could not connect to ::4c3a:433a:4b3a:413a: Connection reset by peer


localhost is mapping to ::4c3a:433a:4b3a:413a but that's not in your allowed_hosts list
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Re: CHECK_NRPE: Receive header underflow - only 0 bytes rece

Postby cocoyanouck » Fri Jun 29, 2018 9:25 am

I'll take a look on that, next monday.

Thank you and have a good week.
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Re: CHECK_NRPE: Receive header underflow - only 0 bytes rece

Postby scottwilkerson » Fri Jun 29, 2018 9:37 am

cocoyanouck wrote:I'll take a look on that, next monday.

Thank you and have a good week.


You have a good weekend too!
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Re: CHECK_NRPE: Receive header underflow - only 0 bytes rece

Postby cocoyanouck » Mon Jul 02, 2018 3:26 am

Hello,

::4c3a:433a:4b3a:413a Is a IPV6 address, that's right ?
If I enter that last on allowed_hosts, it's working fine, great !
Code: Select all
root@Nagios-VZ:/usr/lib/nagios/plugins# ./check_nrpe -H localhost
NRPE v3.0.1


Does that means my server is using ipv6 instead pf ipv4 ...?



So, doesn't matter, next step is this issue (see attachments).
The error seems normal because check_nrpe was installed on /usr/lib/nagios/plugins.

I did this : cp /usr/lib/nagios/plugins/check_* /usr/local/nagios/libexec

But new error :/ (attachments 2)
Attachments
Capture2.PNG
Capture2.PNG (8.14 KiB) Viewed 249 times
Capture.PNG
Capture.PNG (7.64 KiB) Viewed 249 times
cocoyanouck
 
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Re: CHECK_NRPE: Receive header underflow - only 0 bytes rece

Postby scottwilkerson » Mon Jul 02, 2018 10:54 am

cocoyanouck wrote:::4c3a:433a:4b3a:413a Is a IPV6 address, that's right ?

yes

cocoyanouck wrote:Does that means my server is using ipv6 instead pf ipv4 ...?

Yes, or both.

The 2 errors in the picture appear to be problems with check_nrpe in the Nagios server.

Was this compiled on this server?
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