Archive for June, 2009

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VOIP Security

June 24th, 2009 by admin | 1 Comment | Filed in VOIP

Voice over IP is one of the emerging trends in telecommunications that allows telephone calls to be made over computer networks like the Internet by converting analog voice signals into digital data packets. This two-way transmission of conversations using Internet Protocol (IP) combined with many new technologies- VOIP also bring in both security risks and opportunities. VOIP has a very diverse architecture than traditional circuit-based telephony, and this differentiation result in major security issues. Lower cost and greater flexibility that endow with a substantial cost savings over traditional long distance telephone calls, but VOIP should not be installed without vigilant consideration of the security problems introduced.

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Firewalls are important tools for security in today’s IP networks; it’s generally the first line of defense against the attackers. Firewalls work by blocking traffic, which are supposed to be invasive, intrusive, or just simple malicious traffic flowing through them. Also Network Address Translation (NAT) is a dominant tool which can be used to hide Internal network addresses and facilitate a number of endpoints within a LAN to use the same (external) IP address. There are also several issues associated with the transmission of voice data across the NAT, including an incompatibility with IPsec that should be addressed properly while you are going to integrate any such tools for security reason.

Ipsec (Internet Protocol Security)

June 22nd, 2009 by admin | No Comments | Filed in IP Address Lookup

The Internet Engineering Task Force (IETF) in a series of request authoritatively specifies Ipsec (Internet Protocol Security) for Comments addressing to various components and extensions. Ipsec is a protocol suite for securing IP communications by authenticating and encrypting each IP packet of a data stream. IPsec also include protocols for set up the mutual authentication between agents during the beginning of the session and conciliation of cryptographic keys to be used during the session. IPsec is generally being used to protect data flows between hosts such as a computer users or servers, between a pair of security gateway and a host or between the security gateways like routers or firewalls.


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Image Source: redhat.com

IPsec follows two-encryption method which is called- “Transport and Tunnel”, the Transport mode encrypts only the data portion or payload of each packet and leaves the header unscathed while the Tunnel mode encrypts both the header and the payload, as resultant on the receiving area, an IPSec-compliant device decrypts each packet.

IPsec is generally used in “tunnel mode” with a VPN (Virtual Private Network) nonetheless; IPsec also supports a “transport mode” for direct connection between two computers.

IPConfig command-line program & Existing Parameter

June 19th, 2009 by admin | 4 Comments | Filed in windows server 2003

Windows Server 2003 has some handy networking GUI tools that include the IPConfig command-line program which let you find some helpful utility, however you should understand the options you have when using this utility for performing certain operations.

Simply by just inflowing ipconfig at the command line it will return the basic addressing information for your system, which will include the adapter name, IP address, subnet mask, and default gateway.

Here is the list of the existing parameters of IPConfig that should be useful to you.

* /all: let you know all networking information for the system that comprise the host name, node type, adapter names, MAC addresses, DHCP lease information, etc.

* /displaydns: show contents of the DNS resolver cache. This cache keeps DNS information earlier resolved in a local cache for the time period specified in the original request’s (Time To Live) TTL.

* /flushdns: clear the contents of the DNS resolver cache.

* /registerdns: reinstate all DHCP leases on the machine and reregisters them with DNS services.

* /release [adapter name]: after you identify an adapter name or fractional matching name with this parameter, IPConfig releases the address for the specified adapter. If you don’t specify an adapter, IPConfig releases all IP addresses.

* /renew [adapter name]: once you identify an adapter name or partial matching name with this parameter, IPConfig revamp the address for the specified adapter. If you won’t specify an adapter, IPConfig renews all IP addresses.

* /setclassid [connection name][DHCP server class]: This parameter induces the client machine to obtain its DHCP information from a diverse class. The class specified must exist at the DHCP server.

* /showclassid [connection name]: In case the DHCP server has provided a DHCP class, this command will show the details of that class. A DHCP class defines different parameters for different classes of machine.

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Proxy Server and its purpose

June 17th, 2009 by admin | 2 Comments | Filed in Proxy server

A proxy server is a server that acts between users networks and the Internet for seeking resources from other servers. A proxy users connects to the proxy server through a browser initiating access request to some web page, or other resource, available from a different server. The web proxy server analyze and evaluates the request as per its filtering rules such as it may filter traffic by IP address or protocol. If the request gets validated, the proxy provides the resource by connecting to the relevant server and requesting the service on behalf of the user. A web proxy server may modify or adjust the users request or the server’s response, and it may even serve the request without contacting the specified server.

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In this case, it ‘caches’ responses from the remote server, and returns consequent requests for the same content straight way. The purpose of a proxy server is to keep the machines unidentified for security reason and to expedite access to a resource by caching web pages from the web server.

A proxy server can be located in the user’s local computer or at diverse points between the user and the destination servers or the Internet. A reverse proxy is a proxy used as a front-end to accelerate and cache in-demand resources like the web pages. However while choosing a proxy server you should choose the proxy list only based on quality parameters of proxy servers.

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Reverse Proxy Server

June 16th, 2009 by admin | No Comments | Filed in Proxy server

A reverse proxy is a proxy server, which is installed in the region of one or more web servers, as resultant all web traffic coming from the Internet and with a destination of one of the server goes through the proxy server. It set off in-bound network traffic to a set of servers, presenting a single interface to the caller. There are a number of reasons for installing reverse proxy servers:

·Security: the proxy server may provide an extra layer of security by separating or concealing the type of server that is behind the reverse proxy. This configuration may protect the servers further up the chain by making communication intentionally ambiguous.

·Encryption / SSL acceleration: when secure websites are created, the SSL encryption is occasionally not done by the Web server itself, but with a reverse proxy that is being equipped with SSL acceleration hardware the purpose is being solved.

·Load distribution: the reverse proxy can distribute the load to several servers, each server serving its own application area and the proxy may have to rewrite the URLs in each webpage.

·Caching: A reverse proxy can delegate the Web servers by caching static content, such as images, as well as dynamic content, such as a HTML-page deliverd by a content management system. Proxy caches can reduce the load on the central web server.

·Firmness: Since the proxy server relays connection requests for inbound network traffic therefore it can optimize and compress the content to speed up the load time.

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IP Locator Tutorial- Myiptest.com

June 13th, 2009 by admin | 1 Comment | Filed in IP Address Lookup

Myiptest.com is reliable tools to retrieve the country information from IP-address, you can check your IP, DNS lookup, Blacklisted IP addresses, Proxy checkup, reverse DNS lookup and geo locator information. Myiptest.com has an Add-ons for Firefox which show you your external IP address, your proxy (if you use it) and details about your IP Geo Location.

Check here the tutorials;

It’s very simple to install and use: It’s very useful when you use proxy, with this tool you can see if your proxy is precise, anonymous or transparent. For more information about the Product and services related to IP, DNS and Proxy please visit at http://myiptest.com

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Why you should track IP address?

June 11th, 2009 by admin | 3 Comments | Filed in IP Address Lookup

Mapping and Tracing search engines IP addresses is useful for several different reasons. The reason of tracing might be like you may want to see when and which pages of your web site were spidered by search engines robots. You may feel like to ban some harmful bots and let others in. You might want to see which bots are following your robots.txt files.

However keeping track on the various IP addresses belonging to search engine spiders is bit difficult because it requires lot of time. You may need to verify that the IP addresses are indeed genuine and they belong to search engines? The lists you may get might be correct but there is no guarantee that they include all of the IP addresses of all search engines and so on there is no certainty that all of the IP addresses contained in the lists belong to search engines because they are sometimes reassigned or abandoned.

IP tracking also help you to track down the owners of IP addresses or figure out where spam is coming from…but you should know how to track down spammers IP address. .

The IP addresses are enclosed in a flat file database format, which is confined under intellectual property law and treaties, however the IP addresses themselves are public domain and not protected. When you receive an email, the IP Address of the originating computer will contain within the email, in a section of it, which is known as the “headers”. Most of the headers are concealed in most email applications though you can only see the sender’s name, email address, the date and time sent and the subject. However most email applications will allow you to view the complete headers. Check your email application’s help documentation to determine how to do it in your case.

In most cases, you will see a number of lines in the headers that start with the word “Received” followed by a colon (“:”). These are what you might be interested in for looking for. Whenever an email moves from the sender to you, it passes through various servers. Each server adds its own line in the “Received” headers. The newer lines are at the top, so the last “Received” line is that of the original sender.

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