IPVS (IP Virtual Server) implements transport-layer load balancing inside the Linux kernel, so called Layer-4 switching. IPVS running on a host acts as a load balancer at the front of a cluster of real servers, it can direct requests for TCP/UDP based services to the real servers, and makes services of the real servers to appear as a virtual service on a single IP address.

IPVS is commonly used for DNS load balancing as well as other things.

Inkscape supports many advanced SVG features (markers, clones, alpha blending, etc.) and great care is taken in designing a streamlined interface. It is very easy to edit nodes, perform complex path operations, trace bitmaps and much more. We also aim to maintain a thriving user and developer community by using open, community-oriented development.

because it is SVG compatible, you can display it in firefox which makes it very cross-platform. It doesn't have nearly as many stencils as Visio, though.

The main goal of the keepalived project is to add a strong & robust keepalive facility to the Linux Virtual Server project. This project is written in C with multilayer TCP/IP stack checks. Keepalived implements a framework based on three family checks : Layer3, Layer4 & Layer5/7. This framework gives the daemon the ability of checking a LVS server pool states. When one of the server of the LVS server pool is down, keepalived informs the linux kernel via a setsockopt call to remove this server entrie from the LVS topology. In addition keepalived implements an independent VRRPv2 stack to handle director failover. So in short keepalived is a userspace daemon for LVS cluster nodes healthchecks and LVS directors failover.

VRRP is the virtual router redundancy protocol. VRRP is an IETF WG product described at http://www.ietf.org/html.charters/vrrp-charter.html. Excerpt:

A virtual router redundancy protocol is a protocol which allows several
routers on a multiaccess link to utilize the same virtual IP address.
One router will be elected as a master with the other routers acting as
backups in case of the failure of the master router. The primary
motivation to using a virtual router redundancy protocol is that host
systems may be configured (manually or via DHCP) with a single default
gateway, rather than running an active routing protocol. The protocol
should also support the ability to load share traffic when both routers
are up.

Hobbit is a tool for monitoring servers, applications and networks. It collects information about the health of your computers, the applications running on them, and the network connectivity between them. All of this information is presented in a set of simple, intuitive webpages that are updated frequently to reflect changes in the status of your systems.

Hobbit is capable of monitoring a vast set of network services, e.g. mail-servers, web-servers (both plain HTTP and encrypted HTTPS), local server application logs, ressource utilisation and much more.

Intermapper has been around for a very long time. The reference site has only been in place for about a year, prior to that it has been in various places. Intermapper is one of the first tools for network discovery and traffic flow analysis using a GUI.

Intermapper includes a network map, various charting and graphing tools, real-time traffic views between network elements, display of errors, utilization, and more.

PBNJ is a network tool that can be used to give an overview of an machine or multiple machines by identifying the details about the services running on them. PBNJ is different from other tools because it is based on using a scan from nmap parsed to amap. PBNJ parses the data from a scan and outputs to a CSV format file for each ip address scanned.

However, PBNJ is able to handle additional scans and parse the data while only looking for changes. For example, if a machine was updated with a newer version of OpenSSH than was running when the first scan was performed, the CSV file would contain the difference of the scan. Very useful for vulnerability assessment and penetration testing.

UCARP allows a couple of hosts to share common virtual IP addresses in order to provide automatic failover. It is a portable userland implementation of the secure and patent-free Common Address Redundancy Protocol (CARP, OpenBSD’s alternative to the patents-bloated VRRP).

Strong points of the CARP protocol are: very low overhead, cryptographically signed messages, interoperability between different operating systems and no need for any dedicated extra network link between redundant hosts.

The sensorProbe series are intelligent multiport sensor devices for monitoring environmental variations, power, physical threats and security.The SP2 is a completely embedded host with a proprietary Linux like Operating System, including TCP/IP stack, Web server, email and full SNMP functionality. SMS notifications can be sent via a 3rd party email-to-SMS gateway.

The sensorProbe2 comes with a new CPU that is 3 times higher speed compared to the earlier version of sensorProbe2, a faster network connection, new web interface similar to sensorProbe8 series of products including the subnet mask, remote syslog interface. It also includes a battery backed time of day clock. The new sensorProbe2 also has advance events filtering options. Now you can plug in our motion detector to the new sensorProbe2.

An important feature of Pathrate is that it is robust to cross traffic effects, meaning that it can measure the path capacity even when the path is significantly loaded. This is crucial, since the hardest paths to measure are the heavily loaded ones. For more information about how Pathrate works, you can read the following paper: ``Packet Dispersion Techniques and Capacity Estimation'' (to appear in the Transactions on Networking). An earlier version of this paper appeared at Infocom 2001 with the title: ``What do Packet Dispersion Techniques Measure?''.

Pathrate is based on the dispersion of packet pairs and packet trains. Pathrate uses many packet pairs (with packets of variable size) to uncover a set of possible "capacity modes". Then, it uses long packet trains to estimate the so called "Asymptotic Dispersion Rate" R. The capacity of the path will be larger than R, and so this gives a hint about which local modes to reject. From the modes that are higher than R, the one that is the strongest and narrowest is chosen.