Selasa, 25 Oktober 2011

IP Network Design

As we understand it that a computer to communicate with other computers in a TCP / IP, then each computer must have a unique IP address, should not be the same. In order for users on your internal network can communicate with the outside world by using your internal mail-server, then you must make your network IP design very well so that users on the Internet out there also can reach your mail server is located on the internal network with a safe way.



Some of our new air-experiment by creating an Exchange server for example, in addition to master technically how to install Exchange server (eg 2003), there are several steps that sometimes do not know what to diapain to the Exchange server can send a message out to the internet, and The most important is how to create users on the Internet can send an email to our server in a secure manner. Internal IP Network designEg do you already has an Exchange server on your network, you should be able to make the Exchange server can be accessed by all users within the internal network and also users of the Internet can send an email to your internal server in a secure manner. With limited public IP address that you have, then you should plan the use of public IP addresses this well. The following figure shows the network diagram in outline how the public and private IP address in place.In the design of your internal network, private IP address should be used. As described earlier in the design of an IP address, you should use a private IP as in the following table. Design complexity of the IP with "0" and: 1: not discussed again here.Suppose you use a private class C IP address 192.168.10.0/23 to serve as many as 500's hosts. Then you use a subnet mask of 255.255.254.0 (see how to calculate subnet mask). Assuming, of course you do not like in a VLAN network segmentation. In the diagram above picture, you also create an Exchange server with the IP address 192.168.10.251/23 and also Web-server with the IP address 192.168.10.250/23. We know that private IP addresses can not be in route to the Internet, so how do your users access to the outside world and also how users on the Internet reaches your mail-server in the Internal network. How the Internet user can send an email to email_anda@domain-anda.com?Register Your DomainExchange server you can only be accessed by internal users on your network and can not be accessed by Internet users. The first step is you have to register www.domain-anda.com on the Internet through your ISP. You have to buy a public IP address is listed as needed as needed.With the domain is registered on the internet, and you already have several public IP, then the next step is to register your exchange MX records on the DNS server at your ISP by using one public IP address (eg 65.134.10.13) you have. Here is discussed how the Exchange installation and configuration, but still related to the MX record, you also have to create a MX record on your internal DNS to point to the internal server IP Exchange (192.168.10.251/23).The same way you can do for your web-server. Now how the internet user can successfully send an email to your Exchange servers and internal users can also receive the message? Using NATWe need a way to translate private IP addresses into registered IP address by using a method called Network Address Translation (NAT). by NAT, the internet user by using a private IP to send data packets to the internet and vice versa internet user can send packets to the internal network (eg the Exchange Server).You can use this method in the configure NAT on the firewall / router.Assuming you are using a Cisco router, the configuration access-list (eg access-list 101), you must open port 25 (smtp) to allow users on the Internet can reach exchange server via public IP (65.134.10.13) is listed on the DNS server in ISP (our exchange MX records).access-list 101 permit tcp any host 65.134.10.13 eq smtpaccess-list 101 permit tcp any host 65.134.10.13 eq smtpSorry here is not to discuss details of how to use the access-lists in Cisco routers.And to translate exchange your IP address (192.168.10.251) to the public IP address (65.134.10.13), you should use static NAT method. Static NAT is commonly used in order to make the traffic inbound from the Internet into the internal network to the server such as Exchange.Router (config) # ip nat inside source static 192.168.10.251 65.134.10.13Router (config) # ip nat inside source static 192.168.10.250 65.134.10.12Router (config) # interface FastEthernet 0 / 0Router (config-if) # ip address 192.168.10.254 255.255.254.0Router (config-if) # ip nat insideRouter (config-if) # exitThis is an example of a NAT configuration on your router. See also article access-list - the basic configuration of Cisco routers access lists.With this configuration, the router can pass traffic inbound email messages to the Exchange server. Of course you also must have made your Exchange configuration is also the recipient address and so on are certainly not addressed in this article.Make sure also that your ISP is also open port 25. Usually in a WAN connection through an ISP service both frame relay and leased line PPP, all ports are open to you. So you should provide a powerful filter to your firewall / router with a good and strong. However, if the DSL or Cable Internet connection, not infrequently port 25 is closed.Resources in the DMZUsually to provide extra protection to the internal network / private, you can put the Exchange server or Web server on the perimeter or DMZ. With a DMZ, you do not allow inbound traffic from the Internet into a private network but only up to the DMZ network. Of course, the configuration of routers and firewalls must be designed to support this DMZ configuration. See the previous article to know the network DMZ.ConclusionSo that public resources can be accessed from the Internet, the steps that need to be done is to register the domain-anda.com to the Internet and also hosting the MX record (for your Exchange) with a public IP address on your ISP's DNS. The next step is to translate private IP addresses to public IP addresses with NAT method.

taken from various sources

Sabtu, 22 Oktober 2011

The most beautiful beach in Indonesia




Kuta beach is a tourist place located south of Denpasar, the capital city of BaliIndonesia.Kuta is located in Badung regencyThis area is a tourist destination abroadand hasbecome a mainstay tourist island of Bali since the early 70'sKuta Beach is often referred to as beach sunset (sunset beach) as opposed to Sanur beach.

In Kuta there are many shops, restaurants and baths and drying herselfBesides beautiful beaches, Kuta beach also offers a variety of other types of entertainment such as bars andrestaurants along the beach towards Legian beachRosovivo, Ocean Beach Club,Kamasutraare some of the most crowded clubs along the beach of Kuta.

This beach also has a pretty good waves for surfing sports (surfing), especially for novice surfersThe air field I Gusti Ngurah Rai Airport is located not far from Kuta.

Clinton to Raise Rights Issues with Leaders of Tajikistan, Uzbekistan


U.S. Secretary of State Hillary Clinton, right, walks alongside Tajikistan's President Emomali Rakhmon at the Palace of the Nation in Dushanbe, Tajikistan, Oct. 22, 2011.
Photo: AP
U.S. Secretary of State Hillary Clinton, right, walks alongside Tajikistan's President Emomali Rakhmon at the Palace of the Nation in Dushanbe, Tajikistan, Oct. 22, 2011.
U.S. Secretary of State Hillary Clinton told a town hall meeting in Tajikistan's capital, Dushanbe Saturday that she will raise the issue of human rights with both the leaders of Tajikistan and Uzbekistan, which she will visit later in the day.

When asked why she would meet with Uzbek President Islam Karimov, who has been accused of numerous rights abuses, Clinton said no contact meant no influence, and other countries that do not care about human rights would fill the vacuum.

Clinton is on a mission to promote her new Silk Road project, which would increase trade and commerce among Central Asian countries.

Clinton was in Pakistan Friday where she met with Foreign Minister Hina Rabbani Khar.  Clinton urged Pakistan to "take strong steps" to deny Afghan insurgents safe havens and encourage the Taliban to enter peace talks in Afghanistan.

Khar admitted Pakistan could do more in cooperating with other countries to clamp down on the militant safe havens along the Afghan border.  But Khar noted that there are safe havens on both sides of the Afghan border and that there is "no question of any support" by Pakistan to the militants. 

Clinton said Pakistani government officials had helped set up a preliminary meeting between American officials and the Haqqani network to test the al-Qaida-linked group's willingness and sincerity in joining the peace process.

The Haqqani network has launched a number of attacks against U.S. and NATO forces in Afghanistan.  The U.S. has called on Pakistan to do more to crack down on the militant group, which is believed to be based in Pakistan's North Waziristan Tribal region.  

Pakistani officials have so far refused to launch an offensive against the Haqqani network in North Waziristan, saying they want to solidify gains against their own domestic Taliban movement first.

EU Finance Ministers Debate Financial Crisis


German Chancellor Angela Merkel talks with journalists as she arrives for a meeting ahead of an EU summit in Brussels, October 22, 2011.
Photo: AP
German Chancellor Angela Merkel talks with journalists as she arrives for a meeting ahead of an EU summit in Brussels, October 22, 2011.
EU finance ministers meeting in Brussels to discuss how to stabilize banks faced with massive losses related to Greek debt, bailout fund

European Union finance ministers are meeting in Brussels to hammer out details on how to stabilize banks faced with massive losses related to Greece's debt and how to boost the eurozone's bailout fund.

The meeting comes ahead of the EU summit Sunday in the Belgian capital.

German Chancellor Angela Merkel and French President Nicolas Sarkozy have been unable to reach an accord on a common plan.

France wants to turn the continent's bailout fund into a bank that would have access to vast sums of credit from the European Central Bank.  But Germany is advocating that private European banks assume bigger losses on their Greek debt.  France and the continent's central bank argue that would just weaken the banks and lead to further turmoil on the world's financial markets.

One of Europe's leading bankers, Commerzbank chief Martin Blessing in Germany, has said Greece should declare itself bankrupt and restructure its debt.  He said European banks will not voluntarily accept bigger losses on their Greek debt unless the country acknowledges it is insolvent.

On Friday, international lenders said private banks lending money to Greece may have to forgive more than half of what the debt ridden country owes.

The latest review by European Union and International Monetary Fund experts showed that a Greek bond writedown of 50 to 60 percent could still leave the country's debt burden bigger than its yearly economic output by 2020.

European Union finance ministers Friday approved another $11 billion segment of Greece's 2010 international bailout to keep it from going bankrupt.  That leaves only the International Monetary Fund to sign off on the payment, which is a part of the $159 billion bailout.
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