Port Scanner Software

Hey Friends,

I would like to know which is the free and good port scanner software that will show me status of open and close port of a gateway router. I'm having a setup up in which all client computer and server traffic pass through a router. The problem is that we don't have any control over this router, so we are unable to check the access list as well as the firewall configuration on it. In order to confirm that whether this router is stopping traffic i need some good software to detect it. So can any body suggest me some good softwares for doing so? Would be grateful to you if any body help me out to resolve this issue.

Thanks in advance.

AATools Network Monitor displays active services on all ports. Further, AATools Network Monitor maps the ports in use to their respective applications (this feature is available under Windows NT/2000/XP) providing a simple and easy solution to tracking application to port maps. This mapping is extremely useful while monitoring unwanted connections, investigating suspected trojans, viruses, and possible backdoors intrusions.

Atelier Web Security Port Scanner is an innovative network diagnostic tool that adds a new dimension of capabilities to the arsenal of network administrators, information security professionals and all people concerned with safety on PCs. Due to its capability to equate and present to the User the exact reality the Network System is facing, the privileged territory of a true Security Port Scanner starts were the others leave. This major release of Atelier Web Security Port Scanner offers a wealth of state-of-the-art tools for in-depth assessment of Network Security, almost doubling the capabilities of the previous release 3.

A Security Port Scanner, unlike most traditional tools, is not reactive, it is a proactive device for pursuing signs of disaster and anticipating solutions.

Nmap ("Network Mapper") is a free and open source (license) utility for network exploration or security auditing. Many systems and network administrators also find it useful for tasks such as network inventory, managing service upgrade schedules, and monitoring host or service uptime. Nmap uses raw IP packets in novel ways to determine what hosts are available on the network, what services (application name and version) those hosts are offering, what operating systems (and OS versions) they are running, what type of packet filters/firewalls are in use, and dozens of other characteristics. It was designed to rapidly scan large networks, but works fine against single hosts. Nmap runs on all major computer operating systems, and both console and graphical versions are available.

1st Net Scanner is a very useful IP Finder and Port Finder. It builds IP finder, port finder, IP scanner, port scanner and IP tracer, IP tracker, IP camera in one software. It can find IP address, search IP address, trace IP address and scan IP address. And it also can find port, search port and scan port. It's easy and fast! 1st Net Scanner allows for testing whether a remote computer is alive with three types: ICMP, SYN and UDP and testing whether a TCP port is being listened with two types: CONNECT and SYN. 1st Net Scanner reverse lookup IP address into hostname and read responses from connected TCP Port.