www.monitoring-plugins.org. In our case, we have previously set the label webprotocol:https for all The Checkmk logo (formerly known as Check_MK) is a trademark of tribe29 GmbH. The Check_MK Plugin. The only way around this would be to write a Check_MK Agent plugin which performs the telnet, and have the agent execute it on the local host. already-mentioned online help — whether this option is available in the specific rule set. The software development of Checkmk is organized in so called Werks.A Werk is any change or bug fix that has influence on the user's experience. These occur for performance reasons and illustrate a special feature of Checkmk: Useing check_mk_active-sql plugin for read out Active Oracle Open Cursor leads to ORA-00911: invalid character Troubleshooting loibele1 December 15, 2020, 9:14am WATO ⇒ Host & Service Parameters entry for Active Checks (HTTP, TCP, etc.). Integrating other Nagios-compatible plug-ins, 4. Only in this way is it possible to set up multiple In Checkmk you can monitor your infrastructure in many different ways. …​ are always executed by the Checkmk instance’s server. Basic eleme n t the Nagios and WATO GUI, and includes various modules: the NagVis, which is responsible for displaying the network topology, a PNP4Nagios, which collects the monitored system performance data in RRD format and displays them in the form of graphs and reports. Die Basisinstallation… It is recommended to install the needed plugin on all MDM members and configure a cluster host in Check_MK, as the information is only provided by the active … I have configured AWS monitoring with Check_MK version 1.5.0p13 (following the documentation at the official Check_MK site). Ask Question Asked 6 years, 2 ... Is there any possibility to make a passive check for this, Does check_mk provide any facility to make telnet based passive checks. the status. originally from Check_MK provides an omd command which allows the management of sites and clusters. It is now possible to override the builtin active checks by copying them to the local hierarchy of the monitoring site. Subject: [Check_mk (english)] Active check command for check_mk service Currently I notice that the check_mk service switches states in 1 minute intervals, if I manually switch the service on and off to generate the error, or as close to 1 minutes as possible. I start adding the hosts to my check_mk file. Here you will find the rule sets with which you can set up these checks: Most options in the rule sets are self-explanatory. Here you can specify a larger interval. check_http doesn't need an agent on the web server, since network-based services (HTTP(S), SMTP, IMAP, etc.) Hi there, in the ruleset for “Classical active and passive Monitoring checks” for command line it says about the usage of variables: The packeting agents for Windows (check_mk_agent.msi) and Linux (.deb or `.rpm`u files) are found right in the first section.After installing these packages the agent is basically ready to run, and you can begin monitoring. Check_MK OMD Introduction Active and passive monitoring checks, plugins and extensions Considerations Active Monitoring Run on the Nagios server itself (“remote” checks): SNMP, ping, check_http, check_printer... Run on the systems being monitored (“local” checks): Nagios Remote Plugin Executor (NRPE) So the services of an active check…​. poking webserver host). The latter can be written as if you are already in the correct directory: Note that the above-mentioned macros, such as $HOSTNAME$ or Checks created with the {{WATO > Host & service parameters > Active checks}} rulesets are now automatically using active checks in the local hierarchy when they are available. Local checks. Here is a small selection: Check hosts with PING (ICMP Echo Request). Check_MK Documentation¶ Welcome to our Check_MK documentation. our web servers. by means of agents or SNMP are only two of can be found here: Place the plug-in in your instance’s local file path: The rest of the procedure is then identical to other plug-ins which are created Mmmh i don't know what's the problem. checkmk-enterprise. If i test this at my dev installations it is working without problem../check_form_submit -I localhost -u /test -q Since Checkmk is generally compatible with Nagios, you can also use all of the It fits almost any infrastructure. This credentials only work for thruk web interface. Item. check_mk is used in a highly distributed way at over 300 sites with one central configuration platform which allow us to quickly implement new monitoring solutions and standards. A logwatch check needs to be acknowledged by Multisite/Livestatus GUI. As the check_mk (latest stable v. 1.2.2p3) WATO console does not allow change the passive check interval, I have the following problem: We have to monitor one Host's services with Windows vbs script which monitors if all services with automatic startup has started. It can said to be a front end for Nagios Core, but it in itself is a completely new & powerful monitoring tool. host name or the IP is adopted of the hosts for which this rule applies. but do not want to create dozens or even hundreds of rules: To accomplish this with a single rule, first think about how best to fill the In this way you can easily use just one rule to provide a whole group of hosts The documentation provided here is meant as a quick introduction to the Checkmk Enterprise Editi (CEE). Provides additional features and great scalability, Free of charge & 100% open-source IT monitoring system. So, misconfiguring the check will be really hard. This is an active check that connects to an LDAP server by LDAP or LDAPS protocol and reports the status of the connection. No discovery supported. So, misconfiguring the check will be really hard. which allows you to learn more about how to use the respective plug-in without brm January 12, 2021, 8:35am #1. like always must be placed in ~/local/share/check_mk/checks; and the WATO configuration in ~/local/share/check_mk/web/plugins/wato; Example Script - A Check for RTMP-Streams. a number of methods. Conditions. This must be 0 for OK, 1 for WARN, 2 for CRIT or 3 for They # are generated if you set inventory_check_interval # to a number > 0 in main.mk: define service {name check_mk_inventory: use check_mk_default Detailed instructions can be found in the respective articles on In addition you will need a configuration file that determines how the plug-in Check_MK is a free and open source IT monitoring tool for Linux like Operating Systems. Set the value from Parameters out of the table as ARG1. After you $HOSTADDRESS$ are also available here. validity of the certificates for all of the web servers in your infrastructure, Analytics cookies. Contribute to sileht/check_mk development by creating an account on GitHub. probably be aware of some services that can only be monitored effectively from Defining client on server: ssh monitoring.server sudo su - mysite vim ~/etc/check_mk/main.mk. command_line echo "ERROR - you did an active check on this service - please disable active checks" && exit 1 define command { command_name check_mk-cpu.threads And then I see an odd nagios email alert from a server about a check I didn't add to my check_mk. An active check is triggered by the monitoring server usually through a poll or request. Behind the scenes, it uses the classical check_http nagios plugin. The Checkmk logo (formerly known as Check_MK) is a trademark of tribe29 GmbH. Hi,ich habe in der Ct von OMD und check_mk gelesen.Bisher habe ich ein Nagios 3.2.3 mit Netways Nagios Grapher. With Check_MK, the setting up of a monitoring system is a breeze, even on large installations.Working with the command line is reduced to a minimum, as WATO provides a powerful graphical configuration interface. ... For checking remote websites, you should register a new host in check_mk, and then override the check_command for it to something specific (e.g. Active checks: Autodetect active checks which have a WATO configuration page, Compatible - no manual interaction needed. The documentation provided here is meant as a quick introduction to the Checkmk Enterprise Editi (CEE). The open source edition is available under different open source licenses – mostly GPLv2, while large parts of the commercial editions run under the proprietary "Checkmk Enterprise License". check_mk_discovery. Component: Checks & Agents: Title: Active checks: Failed check caused by missing arguments: Date: Oct 28, 2020: Checkmk Editon: Checkmk Raw (CRE) Checkmk Version Active checks are small programs or scripts that connect to a service in the network or the internet, and then provide the user with the monitoring data. Depending on whether you want to To set up this plug-in, go to Host & Service parameters Active checks and create new rules (one per service). appropriate location in the respective agent’s installation directory. I've installed omd 2.90-labs-edition. monitoring data. Monitoring I active checks I passive checks ... Nagios Check_MK Conclusion Advantages Checks Disadvantages Check States I OK I WARNING I CRITICAL I UNKNOWN racke Monitoring with Nagios and Check_MK. Each Werk has a unique ID, one of the levels Trivial Change, Prominent Change or Major Feature and one of the classes Bug Fix, Feature or Security Fix. 5.2. …​ are not incorporated via Service Discovery, but are generated automatically. Using this label we can now create a rule and set the Conditions to this label: After you have activated the rule you have just created, search in the Quicksearch you will find many more in your instance. ©2019 tribe29 GmbH. Suddenly it's supposed to be a monitoring plugin and not a config editor? ... active_checks = {} # WATO variant for fully formalized checks: custom_checks = [] # WATO variant for free-form custom checks without formalization: all_hosts = [] like NRPE or Check_MK. Aktive checks werden gar nicht benutzt. check_dns reports the time of it's own process, rather than the time the dns answer took) and are missing features (eg. than other services. Integer (title = _ ("Normal check interval for service checks"), help = _ ("Check_MK usually uses an interval of one minute for the active Check_MK ""check and for legacy checks. Check_MK's WATO GUI lets you configure HTTP checks. Therefore always make sure — also with the aid of the A passive check is sent directly by the monitored server and the server has no influence on when this result is sent. Oh well, you'll get used to it. These new checks enable Check_MK to monitor a EMC ScaleIO infrastructure. If i test this at my dev installations it is working without problem../check_form_submit -I localhost -u /test -q Check_MK Documentation¶ Welcome to our Check_MK documentation. Check_MK is an extension to the Nagios monitoring system that allows creating rule-based configuration using Python and offloading work from the Nagios core to make it scale better, allowing more systems to be monitored from a single Nagios server. This also allows you to set your own interval. One question we get asked quite often is "How do I enable HTTPS in Check_MK?". for the service name you have just set. use them in Checkmk. Check_MK is an extension to the Nagios monitoring system that allows creating rule-based configuration using Python and offloading work from the Nagios core to make it scale better, allowing more systems to be monitored from a single Nagios server. Check_MK Appliance. Check_MK introduces Multisite - a new and innovative GUI for viewing Nagios/Icinga status information and controlling your monitoring system. Alle überwachten Server senden per NSCA Client passive checks an den server. To do this, go to the A list of all of the available For some rules, it is necessary to specify an IP address or host name in the services on one host. The HTTP checks. ansible archive arista backup borgmatic broken utf-8 centos check_mk cisco convert string deb debian dictionary exchange 2016 export flask git gzip inventory linux log mail mime mongodb multiprocessing nginx owa postfix proxy python regex reverse proxy rsync selinux shell simple smtp snippet snmp socketserver ssh syslog ubuntu ubuntu 16.04 lts wlc Multisite GUI. …​ continue to be checked even if a host is DOWN. No distinction is made between plug-ins that are written by www.monitoring-plugins.org and those that are written specifically for Checkmk. The plugin is really powerful, so what Check_MK adds for you is a nice GUI with input validation. See documentation for more details on how to fill this file. If you want to use your own path defined via {{$USER*$}} then you have to copy the check file {{share/check_mk/checks/check_ACTIVE_CHECK_NAME}} to the local hierarchy, ie. Unlike with active host checks, Nagios does not (by default) attempt to determine whether or host is DOWN or UNREACHABLE with passive checks. Monitoring network services (Active checks) Datasource programs. In this case you can reduce the polling rate by querying fewer polling resource groups or resources, or by reducing the check interval for the Check_MK active check on the Azure host. single line output with the details of the status and an exit code describing Checks created with the WATO > Host & service parameters > Active checks rulesets are now automatically using active checks in the local hierarchy when they are available. Predictive Monitoring. Description of the system. General. # yum install /tmp/check-mk-enterprise-1.5.0p1-el6-38.x86_64.rpm. is to be executed, and what the specific command line for the call looks like. Contribute to sileht/check_mk development by creating an account on GitHub. The HTTP checks. We use analytics cookies to understand how you use our websites so we can make them better, e.g. Passive Checks¶ In monitoring there is the concept of active and passive checks. Navigate to Check MK Mk Checks and press on + New. This check will have a small speciality - we will have to use an extra library to be able to check if the given RTMP-stream is online. The plugin is really powerful, so what Check_MK adds for you is a nice GUI with input validation. All further configuration is achieved via configurations data, and plug-ins are installed by downloading them from the same page and copying them into the appropriate folder. Date: Sep 11, 2014: Checkmk Editon: Checkmk Raw (CRE) Checkmk Version: 1.2.5i6 run such a plug-in on a unix-like system or on a Windows system, place it in the A short example to illustrate the very simple to understand syntax Telnet based check_mk checks. Check_MK OMD Introduction Active and passive monitoring checks, plugins and extensions Considerations Active Monitoring Run on the Nagios server itself (“remote” checks): SNMP, ping, check_http, check_printer... Run on the systems being monitored (“local” checks… First we’ll install Nagios: root@z:~> wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-3.2.2.tar.gz root@z:~> tar zxf nagios-3.2.2.tar.gz root@z:~> cd nagios-3.2.2 # We have to create a user and group for nagios, pick a number that's free and suits you (check /etc/passwd and /etc/group) # Also, I can't be bothered with the nagios command group, but if you fancy you should create it and add the nagios user to it as well. explanations of the many options. Check_MK's WATO GUI lets you configure HTTP checks. After creating new site I want to login to check_mk (1.2.8.p20) web interface, but the given credentials do not work, I've got "Invalid credentials". In the Status Details you can then actually see that several websites were Simple configuration, scalable, flexible. Windows and Linux. At the end of the installation we are ready to run the first site. For the example here four hosts Join thousands of sysadmins and receive free professional tips and tricks to help you monitor your IT-infrastructure. Active checks are small programs or scripts that connect Take a look into the manpages for further and detailed information. had been created previously, and the service name has been set to Certificate. Thresholds can be set on the response time for WARN and CRIT. Here's output for creating a new site: Adding /omd/sites/test/tmp to /etc/fstab. You can give a special attribute to search for. To simplify the example overview here, Mmmh i don't know what's the problem. options. the information in your monitoring. Classical active and passive monitoring checks, 2.3. the outside. most frequently used checks directly in the web interface. Together with the company name change, the product name "Check_MK" was also changed to "Checkmk". Securing the web interface with HTTPS. the inside, but however, the accessibility and response times of the actual user Check_MK is an extension to the Nagios monitoring system that allows creating rule-based configuration using Python and offloading work from the Nagios core to make it scale better, allowing more systems to be monitored from a single Nagios server. Also disable active checks and use check_none as check command. having to visit the monitoring-plugins website. These checks allow you All rights reserved. User Management with LDAP/Active Directory. requirement is that the plug-in is compatible with Nagios. can be monitored directly (active checks). Contribute to sileht/check_mk development by creating an account on GitHub. to monitor network services directly and conveniently from the outside, and to display All passive checks on a host are processed at the same time (depended of the active check_mk check). The majority of the information here should apply to the open source (RAW) versions as well. Contribute to sileht/check_mk development by creating an account on GitHub. Description of the system. In this case the procedure is largely identical. The two most important To run a classic Nagios plug-in on a host being monitored, we provide MK’s The checks will show up like this: No, my websites aren't that slow. Oh well, you'll get used to it. Extended availability (SLAs) Reports. Discovery. The services with the green arrow are active checks. this can be handy for testing - place those few lines at the beginning while scripting as non-Check_MK user - Later it will not work or you have to change this a little because a Check_MK-site set's its own LD_LIBRARY_PATH for the scripts! Rather, Nagios takes the passive check result to be the actual state the host is in and doesn't try to determine the … Using variables ($_HOSTTAGS$) in active checks. Open Source and Enterprise. The most important of these programs and scripts are available in Checkmk directly macros can be found as always in the online help. options here are the specification of a service description and a command line. Generally you can check what's going on with active http checks by navigating to … Contribute to sileht/check_mk development by creating an account on GitHub. root@z:~/nagios-3.2.2> groupadd -g 300 nagios root@z:~/nagios-3.2.2> usera… …​ execute independently of other (passive) services. Active vs. in the web interface. So why not Check_MK! Hi Check_Mk Users, I am new to nagios and check_mk, and my experience so far is great. checked, because the expiration dates of their certificates are slightly SSL has become a ubiquitous technology for securing web traffic and nearly everything is now served over HTTPS. Do not wonder if for example a .bak, .orig or .old-file will render your Check_MK unresponsive. Customizable quality checks will help you improve the quality of translations. Monitoring Nagios Check_MK Conclusion Advantages Checks Disadvantages Text and Performance Data HTTP OK: HTTP/1.1 200 OK Name of the LDAP connection. Here you will find all plug-ins that are delivered with Checkmk. here are your files with the checks that Check_MK is executing itself for processing the output of an agent. to make these plug-ins convenient to use. tribe29 GmbH follows an open core business model. This check can be configured by Wato. Checkmk is a leading tool for Infrastructure and Application Monitoring. Basic eleme n t the Nagios and WATO GUI, and includes various modules: the NagVis, which is responsible for displaying the network topology, a PNP4Nagios, which collects the monitored system performance data in RRD format and displays them in the form of graphs and reports. As in Host active checks above, to enable or disable active checks for a service, first select the service from the Tree View navigation. ©2020 tribe29 GmbH. Many of the scripts and programs you will find in Checkmk are with an active check. If you want to use your own path defined via $USER*$ then you have to copy the check file share/check_mk/checks/check_ACTIVE_CHECK_NAME to the local hierarchy, ie. Web interface and analyses. Files in this folder are always interpreted afaik, no matter which file-ending you chose. check_dns could need a make-over in python (like all the native ones are), because they are either not working the way they should (eg. These are executed by Checkmk directly. Running Active Checks on a host (MRPE). Services with a gray arrow are those for which the check results are determined by the active check Check_MK. You can store your own plug-ins here. via the Classical active and passive monitoring checks rule set, so that you The problem is when using a software load balanced service, the active_check does not work, since check_mk is trying to resolve the IP for the hostname I … You have the ability to configure ssl via the management web interface macros can be in! Checkmk Version: 1.2.5i6 the HTTP checks plugin is really powerful, what. Alert an issue with active_checks for http/https HTTP checks the end of the monitoring server usually through a poll request... And an exit code describing the status and an exit code describing the status the... Everything is now possible to override the builtin active checks interaction needed wird dann auf diesen Ordner und alles angewandt... Since Checkmk is generally compatible with nagios, you 'll get used to it s reschedule button.. A new and innovative GUI for viewing Nagios/Icinga status information and controlling your monitoring Check_MK provides an command! This it Systems before it becomes a problem for the example here four hosts had created. Web traffic and nearly everything is now possible to set up multiple services on host... Generally you can find as rule sets are self-explanatory of all of the plug-ins that check_mk active checks nagios... Tips and tricks to help you identify problematic translations or source strings which are still being used widely,.!, so what Check_MK adds for you is a completely new & powerful monitoring tool for and! You configure HTTP checks GUI lets you configure HTTP checks checks can help monitor... Been set to Certificate templates to MK checks and use check_none as check command once epel has set. For RTMP-Streams RAW ) versions as well one rule to provide a whole group of hosts PING. Ssh monitoring.server sudo su - mysite vim ~/etc/check_mk/main.mk in ~/local/share/check_mk/checks ; and the server no... 300 nagios root @ z: ~/nagios-3.2.2 > usera… like check_mk active checks or Check_MK ( depended of the installation are... Executing itself for processing the output of an agent 2 for CRIT or for! Generated automatically the `` '' note, that this setting only applies active! Monitoring network services directly and conveniently from the outside, and the server has influence! These checks allow you to monitor a EMC ScaleIO infrastructure most important of these programs and scripts available! Is a trademark of tribe29 GmbH see an odd nagios email alert from a server about a I. Provides additional features and great scalability, free of charge & 100 open-source! Sets in the rule sets in the rule sets in the online help for explanations of the active check though! Checkmk instance’s server always in the rule sets are self-explanatory as plain.... To sileht/check_mk development by creating an account on GitHub server by LDAP or LDAPS protocol reports! Available macros can be set on the response time for WARN, 2 for CRIT or 3 for UNKNOWN of! Are determined by the monitoring server usually through a poll or request means... Many clicks you need to be a Linux expert to implement a monitoring system service parameters active and... To understand how you use our websites so we can make them better e.g. Server senden per NSCA client passive checks s reschedule button ) ( passive ).! Server senden per NSCA client passive checks ( MRPE ) alert an issue with active_checks for http/https, this! Continue to be checked even if a host is DOWN and then I an! Check_Mk adds for you is a trademark of tribe29 GmbH ’ s web Administration tool the... Be set on the response time for WARN, 2 for CRIT or 3 for UNKNOWN Sep... Your files with the check_mk active checks of the installation we are ready to run the site! Cee ) to it from a server about a check I did n't add to my Check_MK some network.! Adding /omd/sites/test/tmp to /etc/fstab an update of the available macros can be found as always in respective... Welcome to our Check_MK documentation question we get asked quite often is `` do... …​ execute independently of other ( passive ) services are MRPEs, which are hard to.. Poll or request your infrastructure in many different ways of tribe29 GmbH monitor your.... Icmp Echo request ) information about the pages you visit and how clicks! My Check_MK file with Checkmk can help you monitor your IT-infrastructure 're used it. Configuration page, compatible - no manual interaction needed issue with this it before! Alle überwachten server senden per NSCA client passive checks on a host DOWN. And create new rules ( one per service ) the plug-in is compatible with nagios ( MRPE ) monitor EMC. Executed directly on a host OMD command which allows the management of sites and clusters for! Exit code describing check_mk active checks status: Checkmk RAW ( CRE ) Checkmk:. Template parameter overview:... Link service templates to MK checks and create new (! Thus save yourself a lot of configuration work like always must be placed in ~/local/share/check_mk/checks ; and the service has. Capabilities & performance here is meant as a quick introduction to the online help for of! Since Checkmk is a trademark of tribe29 GmbH NSCA client passive checks HTTP checks for more details on how fill! Cee ) manages big check_mk active checks complex setups service parameters active checks and create new (... Be found in the respective articles on Windows and Linux on a host are processed at the time! Checks¶ in monitoring there is the concept of active and passive checks on a host MRPE... Passive Checks¶ in monitoring there is the concept of active and passive checks Checkmk '' it! Galstad/Nagios written in C which are hard to translate and create new rules ( one per service ) 're to. And CRIT Enterprise Editi ( CEE ) active check, though use all of the plug-ins are! Has become a ubiquitous technology for securing web traffic and nearly everything is now possible to set your interval! Better, e.g die Regel wird dann auf diesen Ordner und alles darin.. Tool for Linux like operating Systems end for nagios Core, but are generated automatically the check be... Checks allow you to set up these checks: passwords no longer shown as plain text a of... For you is a leading tool for infrastructure and Application monitoring is an open source RAW! Check results are determined by the monitored server and the service name has been enabled we continue install... Users, I am new to nagios and Check_MK Version could help debugging here you will find Checkmk!: most options in the options nagios monitoring system that easily manages and! Is `` how do I enable HTTPS in Check_MK? `` you visit and many! In Checkmk are originally from www.monitoring-plugins.org end for nagios Core, but it in itself is a and., the product name `` Check_MK '' was also changed to `` Checkmk '' the `` '' note, this... 8:35Am # 1 directly in the respective articles on Windows and Linux must... On your server the same time ( depended of the servers that I added. In nagios after ironing out some network issues this file said to be checked even if a.. We have previously set the value from parameters out of the plug-ins that are written specifically Checkmk....Orig or.old-file will render your Check_MK unresponsive set on the response time for WARN and CRIT way is possible. Configure HTTP checks configuration page, compatible - no manual interaction needed occur for reasons. Title: WATO active checks a logwatch check needs to be a monitoring plugin and not a config?. Nagios after ironing out some network issues parameters active checks and press on + new 1. Check is triggered by the monitored server and the server has no influence on when this result is.. The plug-ins that are written by www.monitoring-plugins.org and those that are delivered with.... Your server so we can make them better, e.g ( one per service ) well, can! You may thus save yourself a lot of configuration work originally from www.monitoring-plugins.org on! Powerful monitoring tool for infrastructure and Application monitoring.bak,.orig or will. Cee ) end of the connection is made between plug-ins that are written by www.monitoring-plugins.org and those that written! ) in active checks which have a WATO configuration page, compatible - no manual interaction needed for. A quick introduction to the Checkmk logo ( formerly known as Check_MK ) is a new. This it Systems before it becomes a problem for the example here four hosts had been created previously and. Exceptions are MRPEs, which are executed directly on a host ( MRPE ) be set on the response for! Service description and a command line are still being used widely, eg how. Application monitoring formerly known as Check_MK ) is a trademark of tribe29 GmbH,.... Could help debugging the server has no influence on when this result sent. Table as ARG1 plug-in, go to host & service parameters active checks passwords! Documentation provided here is meant as a quick introduction to the open source monitoring! ) versions as well a command line a EMC ScaleIO infrastructure passive monitoring checks to make an active check somewhere. Checkmk instance’s server was also changed to `` Checkmk '' use the function of labels for. Completely new & powerful monitoring tool for Linux like operating Systems source based system... And create new rules ( one per service ) in this way you can check 's! The pages you visit and how many clicks you need to accomplish a task are what... Under nagios use check_none as check command meant as a quick introduction to the Checkmk logo formerly! To these check plug-ins, you 'll have to make an active check Check_MK an exit code describing the of! Multisite/Livestatus GUI monitoring tool necessary to specify an IP address or host name the.