Renungan Menyambut Datangnya Bulan Suci Ramadhan 1431 H

Ketika kami sedang bersama Rasulullah SAW di kediaman seorang sahabat Anshar, tiba-tiba terdengar panggilan seseorang dari luar rumah: “Wahai penghuni rumah, bolehkah aku masuk? Sebab kalian akan membutuhkanku.”

Rasulullah bersabda: “Tahukah kalian siapa yang memanggil?”

Kami menjawab: “Allah dan RasulNya yang lebih tahu.”

Beliau melanjutkan, “Itu Iblis, laknat Allah bersamanya.”

Umar bin Khattab berkata: “Izinkan aku membunuhnya wahai Rasulullah”.

Nabi menahannya: “Sabar wahai Umar, bukankah kamu tahu bahwa Allah memberinya kesempatan hingga hari kiamat? Lebih baik bukakan pintu untuknya, sebab dia telah diperintahkan oleh Allah untuk ini, pahamilah apa yang hendak ia katakan dan dengarkan dengan baik.”

Ibnu Abbas RA berkata: pintu lalu dibuka, ternyata dia seperti seorang kakek yang cacat satu matanya. Di janggutnya terdapat 7 helai rambut seperti rambut kuda, taringnya terlihat seperti taring babi, bibirnya seperti bibir sapi.

Iblis berkata: “Salam untukmu Muhammad. Salam untukmu para hadirin…”

Rasulullah SAW lalu menjawab: “Salam hanya milik Allah SWT, sebagai mahluk terlaknat, apa keperluanmu?”

Iblis menjawab: “Wahai Muhammad, aku datang ke sini bukan atas kemauanku, namun karena terpaksa.”

“Siapa yang memaksamu?”

Seorang malaikat dari utusan Allah telah mendatangiku dan berkata:

“Allah SWT memerintahkanmu untuk mendatangi Muhammad sambil menundukkan diri.beritahu Muhammad tentang caramu dalam menggoda manusia. jawabalah dengan jujur semua pertanyaannya. Demi kebesaran Allah, andai kau berdusta satu kali saja, maka Allah akan jadikan dirimu debu yang ditiup angin.”

“Oleh karena itu aku sekarang mendatangimu. Tanyalah apa yang hendak kau tanyakan. Jika aku berdusta, aku akan dicaci oleh setiap musuhku. Tidak ada sesuatu pun yang paling besar menimpaku daripada cacian musuh.”

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Interconnection IPv4 and IPv6 with Automatic Mechanism Tunneling

With the development of internet technology is increasingly rapidly causing more and more internet users. But it added the internet user is not matched with the number of IPv4 addresses. So IETF issued a new IP protocol standard called IPng (Internet Protocol Next Generations) or also known as IPv6. IPv6 address format and has a different header with IPv4. So that IPv4 can not directly interconnect with IPv6.  This can cause problems in the implementation of IPv6 in the IPv4 Internet network that has been installed.  As  solution to this problem required an implementation of IPv6 transition mechanism for IPv6.  The aim of making this transition mechanism is so that IPv6 packets can be passed into the existing IPv4 networks or conversely.

Automatic Tunneling Mechanism functioning IPv6 packets pass through IPv4 network which has
there, without changing the IPv4 network infrastructure. Automatic Tunneling mechanism has a working principle encapsulates IPv6 packets with a header IPv4, then the package is immediately sent to the IPv4 network. The function of the encapsulation of IPv6 packets with IPv4 header is for the package can diroutingkan by routers IPv4. However with the addition of the IPv4 header is certainly going to increase in size, according to the packet length IPv4 header length is 20 byte. Accretion this package will also result in increased delay time the main paket. Question shipping of the implementation of IPv6 transition mechanism is the accretion time delay the process due to the length packets, the encapsulation process and the process decapsulation.

Automatic Tunneling Transition Mechanism has advantages :

  1. Easier in implementation.
    In the implementation does not require much computer, simply use a computer
    already there. especially for the gateway tunnel, the OS needs to be upgraded to the operating dualstack system which supports IPv6 and IPv4.
  2. It’s easier in terms of configuration at the operating system.
    In the configuration script is not needed a complex configuration script, simply by
    tunnel interface configuration and configuration of routing tables only.
  3. Does not require a server that serves the transition.
    In the implementation does not require a special server that serves the transition mechanism, encapsulation and decapsulation is done in a tunnel between the gateway and point-to-point.

Weaknesses :

  1. Can not be implemented if the client is in transition NAT router.
  2. Will cause added delay (processing time).
  3. Vulnerable to DDOS attacks.