Tag: ntopng

ntopng

Identifying Suspicious Flows: Network Issues or Misbehaving Hosts ?

Starting from the latest 3.9 version, ntopng features and handy dropdown menu that allows you to filter flows on the basis of their current TCP state. Being able to filter flows on the basis of their TCP state is particularly useful as it allows to separate the normal flows from those that are suspicious or symptomatic of certain network issues. For example, one can unveil: Flows that only have a client SYN. This can identify clients attempting to connect to a server that is no longer responding (down?) or misbehaving …
n2disk

Drill Down Deeper: Using ntopng to Zoom In, Filter Out and Go Straight to the Packets

ntopng has grown significantly over the past years, providing an increasingly-interesting set of features to support network analysts and troubleshooters in their decisions. Among the most relevant features, it is worth mentioning that timeseries inspection pages have been redesigned and reworked profoundly to facilitate the drill-down of historical data. Similarly, a home-grown high-speed special-purpose flow database has been seamlessly integrated in ntopng to ease the storage and retrieval of historical flows. However, the circle was not really closed. A piece was missing. Something that could take us down to the …
ntopng

ntopng Disk Requirements for Timeseries and Flows

Being able to do a priori estimations of the space that ntopng is going to use in a production environment is fundamental for the provisioning of the storage. In this post we try to estimate the space used by ntopng to store timeseries and flows. Timeseries The number of timeseries generated by ntopng depends almost exclusively on the number of local hosts. Other timeseries generated, including those for the interfaces or SNMP devices, are generally orders of magnitude less than those generated for local hosts. For this reason, it is …
Components

Remote ntopng Authentication with RADIUS and LDAP

In large organizations, it is common to have a centralised authentication system usually named AAA (Authentication, Authorization and Accounting). Managing users typically involves the definition and enforcement of the rights to do some operations or to access certain resources in a network. Being able to grant (or deny) such rights using a centralized authentication system is the only viable solution when it comes to dealing with large organizations with hundreds, or even thousands, of users that periodically join and leave. AAA protocols include Remote Authentication Dial-In User Service (RADIUS) and …
ntopng

Best Practices to Secure ntopng

After a fresh install, ntopng will run using a default, basic configuration. Such configuration is meant to provide an up-and-running ntopng but does not try to secure it. Therefore, the default configuration should only be used for testing purposes in non-production environments. Several things are required to secure ntopng and make it enterprise-proof. Those things include, but are not limited to, enabling an encrypted web access, restricting the web server access, and protecting the Redis server used by ntopng as a cache. Here is the list of things required to …
ntopng

ntopng goes Elastic: Introducing ElasticSearch 6 Support

As you ntopng users know, out of the Elastic toolset ntopng supports both ElasticSearch and LogStash. You can use them using the -F flag: --dump-flows|-F] <mode> | Dump expired flows. Mode: | es Dump in ElasticSearch database | Format: | es;<mapping type>;<idx name>;<es URL>;<http auth> | Example: | es;ntopng;ntopng-%Y.%m.%d;http://localhost:9200/_bulk; | Notes: | The <idx name> accepts the strftime() format. | <mapping type>s have been removed starting at | ElasticSearch version 6. <mapping type> | values whill therefore be ignored when using | versions greater than or equal to 6. | …
nProbe

Network Monitoring 101: A Beginner’s Guide to Understanding ntop Tools

The first important step to start with network monitoring is to analyze what we want to monitor and how to deploy the monitoring solution in the existing network. Here are some important questions to ask ourselves before starting the actual monitoring: Do we need to monitor the entire network or just a specific segment? Do we already have network appliances with network flow export capabilities (e.g. NetFlow/sFlow devices)? Can we use port mirroring of a switch or a network TAP? Where are we deploying our network monitoring appliances to get …
Announce

Announcing ntopng 3.2 – The First Move Towards Active Network Monitoring

Today we are glad to announce the new 3.2 stable release of ntopng. Among the most important new features available in this release, there is without any doubt an advanced network devices discovery functionality. Historically, ntopng has always been a fully passive monitoring tool. This release aims at complementing the information gathered from a purely passive packet capture with precious extra bits of data obtained by actively searching for devices. Network devices discovery glues together multiple techniques and heuristics, including ARP pinging, SNMP querying, SSDP discovery and MDNS names resolution. …
ntopng

ntopng Grafana Integration: The Beauty of Data Visualizazion

Disclaimer This article is outdated: please see this document for using ntopng with grafana Summary Grafana is one of the most widely known platforms for metrics monitoring (and alerting); ntopng version 3.1 natively integrates with Grafana thanks to a datasource plugin which is freely available; This article explains how to install and configure the ntopng datasource plugin, and how to build a dashboard for the visualization of ntopng-generated metrics. A video tutorial is available as well: Introduction Grafana is an open platform for analytics and visualization. An extremely-well engineered architecture makes …
ntopng

Monitoring Network Devices with ntopng and SNMP

Summary SNMP is widely used for network monitoring. Being able to remotely monitor network devices is fundamental to have a clear picture of present and past network health. ntopng systematically interacts with SNMP devices to provide historical and real-time insights on the network. ntopng SNMP support Simple Network Management Protocol (SNMP) is one of the de-facto standards used to remotely monitor network devices such as routers, switches and servers, just to name a few. With ntopng Enterprise it is possible to consistently and programmatically interact with those devices to have a real-time view …
Guides

Filling the Pipe: Exporting ntopng Flows to Logstash

Logstash comes in very handy when it is necessary to manipulate or augment data before the actual consolidation. Typical examples of augmentation include IP address to customer ID mappings and geolocation, just to name a few. ntopng natively supports network flows export to Logstash. The following video tutorial demonstrates this feature. …
ntopng

ntopng MySQL Flow Export: Increase the Maximum Number of Open Files

ntopng uses partitioned MySQL tables when storing flows. As MySQL needs a file handle for each partition and its index, it is important to make sure that the open_files_limit is large enough to allow the process to keep all these files open. Typically, open_files_limit  default value works out-of-the-box but there are some packages/distributions that keeps this number pretty low. When the current value is too low, ntopng can show errors such as [MySQLDB.cpp:55] ERROR: MySQL error: Out of resources when opening file './ntopng/flowsv6#P#p23.MYD' (Errcode: 24 - Too many open files) [rc=-1] …