Mengganti DNS dengan DNS Publik Milik Google dan OpenDNS

Bagi pengguna internet di Indonesia, sering kali kita mendengar cerita tentang layanan yang kurang memuaskan dari pihak internet provider. Mulai koneksi yang sering putus, download super lambat, biaya langganan yang mahal dan masih banyak lagi. Meskipun kenyataannya seperti itu, kita sebagai anak negeri tetap harus berfikir positif dan berharap agar kedepannya masalah tersebut dapat teratasi sehingga kita bisa menikamati koneksi internet yang berkualitas dan tentunya dengan harga yang lebih murah

Salah satu sebab mengapa koneksi internet di Indonesia sering putus adalah dikarenakan DNS server yang dipakai oleh internet service provider (ISP) kurang memadai dalam melayani banyaknya member yang berlangganan pada provider tersebut. Untuk mengatasi hal itu, kita sebagai konsumen bisa melakukan komplain kepada pihak ISP tentang DNS server yang mereka sediakan.

Jika hal tersebut tidak memungkinkan, kita juga bisa menggunakan DNS publik luar negeri yang memang disediakan bagi pengguna internet di seluruh dunia. Ada dua DNS publik yang terkenal dikalangan pengguna internet yaitu OpenDNS dan Google DNS. Soal kualitas, jangan ditanyakan lagi karena memang keduanya mempunyai kualitas yang lebih baik jika dibandingkan DNS yang disediakan oleh ISP di Indonesia. Pendapat ini hanya pendapat pribadi kami selama menggunakan layanan ISP Indonesia.

Google DNS Public 8.8.8.8 dan 8.8.4.4

OpenDNS Public 208.67.222.222 dan 208.67.220.220

Jika ingin menggunakan DNS publik milik Google dan OpenDNS, ikuti petunjuk berikut ini :

• Buka Control Panel, kemudian pilih Network Connections.
• Pilih jenis koneksi apa yang ingin anda gunakan. Sebagai contoh pada kantor kami, kami menggunakan wireless sebagai default dari koneksi internet, maka yang harus dirubah adalah setting DNS pada wireless tersebut.
  
• Klik kanan wireless dan pilih Properties.
• Klik bagian Internet Protocol TCP/IP dari jendela network yang terbuka, kemudian klik tombol Properties.
  
• Pada bagian Use the following DNS addresses, gunakan DNS dari OpenDNS atau Google DNS. Anda juga bisa mengkombinasikan antara keduanya.
  
• Kil tombol OK dan lanjutkan klik Close pada bagian Network Connections.

Jika ingin memaksimalkan dan mempercepat koneski internet, anda juga bisa mematikan service dari QOS Packet Scheduler pada bagian Network Connections (Mematikan QOS Packet Scheduler bisa mempercepat koneksi internet hingga mencapai 20% dari kecepatan semula).

Trik ini dapat diaplikasikan pada semua ISP yang anda pakai, baik itu melalui kabel telephone, modem GSM, modem CDMA, satellite atau juga bisa digunakan pada hotspot milik publik seperti yang ada di mall atau

Audit Keamanan dan Eksplorasi Jaringan dengan Nmap

Pernahkah anda menonton film Trilogi Matrix, jika pernah pasti anda pernah melihat sebuah software yang digunakan untuk menscanning suatu jaringan dan membobol sistem tangga darurat. Nah, software tersebut benar-benar ada di dunia nyata, software tersebut adalah nmap.

Nmap / Network Map adalah sebuah aplikasi yang dapat Anda pakai untuk memonitor jaringan Anda dari berbagai virus dan serangan yang mencurigakan. Termasuk untuk mengecek kesalahan konfigurasi jika memang ada. Nmap memang di desain untuk menjadi sebuah utilitas gratis untuk penjelajahan jaringan atau audit keamanan. Banyak administrator sistem dan jaringan juga merasakan bahwa program ini sangat berguna untuk beberapa pekerjaan seperti network inventory, mengatur setting jaringan, penjadwalan upgrade, dan monitoring penyimpanan data.

Nmap menggunakan paket IP raw dengan cara yang baru untuk menentukan apa saja yang tersedia di dalam jaringan, layanan apa saja (nama aplikasi dan versi) yang disimpan atau di-hosting yang ditawarkan, system operasi apa (dan versi berapa) yang berjalan, paket filter / firewall apa yang sedang digunakan, dan puluhan karakteristik lainnya. Program ini memang dirancang untuk secara cepat melakukan scanning jaringan yang besar, tetapi tetap bekerja dengan baik pada setiap komputer tunggal.

Beberapa fitur nmap adalah

• Flexible mendukung banyak sekali teknik canggih untuk memetakan jaringan dengan menggunakan IP Filters, firewall, router, dan hambatan lainnya. Ini juga memiliki beberapa mekanisme port scanning (baik TCP dan UDP), deteksi OS, deteksi versi, ping sweeps, dan lain sebagainya.
• Powerful Nmap telah digunakan untuk scanning jaringan yang besar dari ratusan ribu mesin.
• Portable kebanyakan system operasi telah di dukung oleh Nmap. Beberapa di antaranya termasuk Linux, Microsoft Windows, FreeBSD, OpenBSD, Solaris, IRIX, Mac OS X, HP-UX, NetBSD, Sun OS, Amiga, dan lain lain.
• Free Software ini tersedia secara gratis.
• Desain, saat ini terdapat nmap versi GUI, yaitu zenmap, dan tutorial dibawah akan mengajarkan anda bagaimana menggunakan nmap versi GUI tersebut.

Dalam tutorial dibawah, anda akan disuguhkan bagaimana cara menscanning atau mengaudit sebuah jaringan. Oke langsung saja,

• Disini kita anggap IP yang kita miliki adalah 10.151.43.135 dan akan menscan atau mengaudit sebuah IP server yaitu 10.151.31.2 (masih dalam satu big subnet dengan IP kita)
• Download terlebih dahulu Zenmap (nmap versi GUI) di http://nmap.org/dist/nmap-5.51-setup.exe
• Kemudian jalankan installernya seperti biasa. Setelah terinstall, langsung buka programnya.
• Untuk zenmap ini kita sangat dimudahkan untuk memerintahkan nmap, kita tidak perlu capek-capek mengetik dalam command prompt, cukup dengan memilih list tipe scanning apa yang ingin kita jalankan, maka zenmap bisa langsung menggenerate command nmap-nya
• Oke langsung saja, kita akan lakukan “intense scan” dengan zenmap, kita ganti profilenya ke mode “intense scan”, kemudian isikan targetnya dengan 10.151.31.2. maka secara langsung textfield command akan terisi “nmap –T4 –A –v 10.151.31.2”

• Oke, proses scanning sedang berlangsung, setelah menunggu, kita bisa melihat hasil output dari proses scanning tadi. Antara lain adalah nmap output, ports/hosts, topology atau host details. Dan lagi-lagi kita tidak perlu susah-susah mengetikkan command-command itu, dengan zenmap kita hanya mengeklik tab-tab perintah yang sudah disediakan.

Berikut ini daftar ports dan protocol yang telah di pindai

Gambar topology IP target dengan IP kita

Gambar informasi detail IP target kita

Daftar jenis profile atau jenis scan yang disediakan oleh zenmap

Dengan adanya software scanning dan audit jaringan seperti nmap ini, sangat bermanfaat bagi para administrator jaringan. Karena dengan bantuan freeware ini kerja mereka sangat-sangat terbantu. Terutama bagi adminsitrator yang mengawasi jaringan vital dan sering diserang para peretas.

Read more: http://blog.fastncheap.com/audit-keamanan-dan-eksplorasi-jaringan-dengan-nmap/#ixzz1rF9gviGJ

keunggulan dan alasan kenapa harus menggunakan Firefox

Sorry ni untuk agan-agan semua bukan untuk membela salah satu web browser, tapi ini hanya sekedar sharing biasa. Bagi yang terbiasa menggunakan internet, tentunya semua sudah tahu keunggulan dari web browser Mozilla Firefox dibandingkan dengan web browser lain. Bagi yang belum pernah atau jarang menggunakan firefox, ada baiknya mencoba menggunakannya sebagai default dari web browser yang anda miliki.

Beberapa keunggulan dan alasan kenapa harus menggunakan Firefox sebagai web browser saat surfing di internet adalah sebagai berikut :

1) Standard Compliant.

Dukungan rendering dari Gecko yang telah berstandard W3C (Badan yang mengurusi perkembangan aplikasi web) menjadi bagian penting dari firefox. Kode dan cara penggunaannya memudahkan seorang developer web untuk membangun website bagi firefox.

2) Tersedia dalam berbagai platform OS.

Tidak perlu dipungkiri lagi, karena firefox merupakan apliaksi open source, aplikasi ini tersedia untuk berbagai platform, mulai dari Windows, Linux maupun Mac OS X.

3) Mencegah adanya kegiatan phishing ke komputer anda.

Phishing merupakan upaya seseorang untuk mencuri identitas pribadi yang anda miliki yang biasanya anda masukkan pada komputer. Data-data yang dicuri biasanya berupa mail, password, nomor telephone, nomor rekenng bank, paypal dan data penting lain yang anda miliki.

Firefox menyimpan banyak database website phishing yang akan menyerang anda. Jadi jika secara kebetulan anda mengunjungi situs tersebut, firefox akan memperingatkan anda untuk tidak mengunjunginya.

4) Memiliki Tab yang maksimal.

Meskipun pada Internet Explorer versi baru menyediakan Tab sebagai default navigasinya, namun Tab di firefox masih lebih baik karena dapat bekerja secara mumpuni. Anda dapat memilih, memindah, menggeser ataupun membuka pada jendela baru dan meninggalkan window lama jika menginginkannya.

Jika anda terbiasa menggunakan Safari, sekarang firefox sudah menyediakan tab Candy yang fungsinya hampis sama dengan pengaturan tab pada Safari Web Browser.

5) Banyak Add-on yang bisa diintegrasikan.

Point ini yang paling membedakan firefox dengan web browser seperti IE. Anda bisa menambahkan berbagai macam Add-on yang akan menambah fungsionalitas dari firefox itu sendiri. Bahkan ada yang bilang, firefox adalah bagian kecil dari Add-on karena tanpa Add-on, firefox tidak akan menjadi web browser terbaik.

6) Bisa Dijadikan Aplikasi Portable.

Jika anda sering berganti-ganti perangkat komputer, tersedia aplikasi portable firefox yang bisa diinstall di flash disk. Tidak perlu melakukan install tiap berganti komputer karena firefox sudah ada di flash disk.

7) Firefox adalah Web Browser paling keren yang pernah kami gunakan.

Kalau ini hanya pendapat subyektif, karena hanya berdasar pada pengalaman kami saat browsing di internet.

Pada pembahasan diatas kami menyebutkan beberapa kelebihan dari firefox dan tidak etis kalau kami hanya menyebutkan kelebihan tanpa menyebutkan kekurangan dari firefox. Berikut adalah kekurangan dari firefox :

1) Start-up time lebih lama.

Memang benar, jika kita banyak menambahkan Add-on, aplikasi ini menjadi berat saat baru pertama loading. Untuk mengatasinya, coba disable add-on yang jarang digunakan. Jangan di uninstall karena mungkin suatu hari anda membutuhkannya lagi.

2) Add-on yang tidak berfungsi.

Ketika firefox versi baru dirilis, banyak add-on yang tidak berfungsi karena perbedaan engine dari firefox sebelumnya. Kalau ini hanya tinggal menunggu waktu saja karena pihak developer add-on dalam waktu dekat akan merilis versi update dari add-on yang mereka buat.

3) Crash saat Loading

Hal ini biasanya terlalu banyak Add-on yang dinstall atau anda mengugnakan firefox versi lama. Anda bisa mengatasinnya dengan menguninstall add-on atau menginstall firefox versi terbaru.

Kesimpulan :

Meskipun masih memiliki kekurangan, firefox bisa dipastikan lebih unggul dari web browser yang lain. Anda bisa dengan menambahakn add-on untuk memenuhi kebutuhan anda saat berselancar di internet.

Jika memiliki pendapat atau pengalaman lain dengan web browser, bagi pengalaman anda dengan meninggalkan komentar pada bagian akhir dari artikel ini.

contoh program IP finder dan port scanner

import java.io.IOException;

import java.net.InetAddress;

import java.net.Socket;

import java.net.UnknownHostException;

import javax.swing.DefaultListModel;

import javax.swing.JOptionPane;

Bagian diatas merupakan pustaka kelas objek java. yang di organisasikan menjadi beberapa kelompok. Pada bagian diatas package yang digunakan antara lain. import java.io memuat kelas untuk keperluan input output seperti DataInputStream, DataOutputStream, dan lain sebagainya. import java.net memuat kelas untuk keperluan jaringan/internet, DatagramSocket, InetAddress, URL, URLConnection. javax.swing memuat kelas untuk perluasan daei objek GUI dengan fungsi dan control baru yang lebih baikdari kelas AWT.

String hostname;

int Awal,Akhir;

InetAddress test;

Bagian diatas merupakan kelas dan variable yang akan digunakan dalam mengakses IP, port, dan batasan pada port yang akan diakses. Mendeklarasikan variable hostname yang bertipe data String. Mendeklarasikan variable test bertipe InetAddress. Mendeklarasikan variable Mulai dan Akhir bertipe integer.

private void jprosesActionPerformed(java.awt.event.ActionEvent evt) {

// TODO add your handling code here:

//IP finder

try {

hostname=jinputweb.getText();

InetAddress ipaddress = InetAddress.getByName(hostname);

System.out.println("IP address: " + ipaddress.getHostAddress());

jhasilIP.setText(ipaddress.getHostAddress());

}

catch ( UnknownHostException e ){

String pesan =(hostname + " tidak ditemukan, "

+ "cek ulang alamat yang anda masukkan !");

JOptionPane.showMessageDialog(this,pesan,"PERINGATAN",

JOptionPane.ERROR_MESSAGE);

}

Pada bagian try&catc merupakan bagian yang digunakan untuk melakukan test apakah alamat yang diinputkan ada dalam jaringan internet atau tidak. Bagian InetAddress ipaddress = InetAddress.getByName(hostname);digunakan untuk melakukan pencarian nomor IP, apabila di temukan akan di tampilkan pada perintah system.out.prinln(()); dan apabila tidak di temumukan akan muncul peringatan. Cek ulang alamat uang anda masukkan.

for ( port = Awal; port < Akhir; port++) {

try {

Socket s = new Socket(hostname,port);

System.out.println("Server is listening on port " + port+ " of " + hostname);

String pesan3=("Port nomor " +port+ " terbuka dari " + hostname);

jListportopen.setModel(pilih);

pilih.addElement(pesan3);

s.close();

}

catch (IOException ex) {

System.out.println("Server is not listening on port " + port+ " of " + hostname);

String pesan4=("Port nomor " +port+ " tertutup dari " + hostname);

jListportclose.setModel(pilih2);

pilih2.addElement(pesan4);

}

Pada bagian diatas merupakan bagian yang digunakan untuk melakukan port scanning (melakukan test pada port yang terbuka dan tertutup). Dengan bantuan for dapat dilakukan perulangan pada port satu per satu. Perintah try…. catch… digunakan untuk mengantisipasi apabila ada port yang tidak terbuka hingga tidak terjadi error. Port yang terbuka dan tertutup akan ditampilkan setelah preses scanning telah selesai di lakukan. Terdapat peringatan bahwa scanning telah selesai dilakukan.

Awal = Integer.parseInt(jawal.getText());

Akhir = Integer.parseInt(jakhir.getText());

test = InetAddress.getByName(jinputweb.getText());

scan(test);

}

catch (UnknownHostException ex) {

}catch (NumberFormatException ne)

{

String pesan2 =("Input Harus Angka, Ulangi lagi input anda!!");

JOptionPane.showMessageDialog(this,pesan2,"PERINGATAN",

JOptionPane.ERROR_MESSAGE);

jawal.setFocusable(true);

perintah diatas digunakan untuk memasukkan nilai range pada port yanga kan kita scann. Disini range port harus bertipe data integer (angka) apabila kita memasukkan selain angka akan muncul kotak dialog inputan harus angka. Saya menggunakan range port karena untuk membatasi pada port berapa akan di lakukan scanning mengingat jumlah port sebanyak 65536. Jadi apabila akan melakukan penyecanan dalam jumlah sebanyak itu maka akan memerlukan waktu yang cukup lama.

jawaban CCNA final exam

Final Exam

1. Refer to the exhibit. Host B attempts to establish a TCP/IP session with host C. During this attempt, a frame was captured at the FastEthernet interface fa0/1 of the San Francisco router. The packet inside the captured frame has the source IP address 10.10.1.2, and the destination IP address is 10.31.1.20. What is the destination MAC address of the frame at the time of capture?
• 0060.7320.D632**
• 0060.7320.D631
• 0040.8517.44C3
• 0009.B2E4.EE03
• 0010.C2B4.3421

2. What are three characteristics of CSMA/CD? (Choose three.)
• It monitors the media for presence of a data signal. **
• After detecting a collision, hosts can resume transmission after a random timer has expired. **
• A jam signal is used to ensure that all hosts are aware that a collision has occurred. **
• Devices can be configured with a higher transmission priority.
• Data is transmitted only when the data signal is present.
• It uses a token system to avoid collisions.

3. Refer to the exhibit. The PC, the routing table of which is displayed, is configured correctly. To which network device or interface does the IP address 192.168.1.254 belong?
• PC
• switch
• router interface fa0/0**
• router interface fa0/1

4. Refer to the exhibit. Host A wants to access the Internet. Which combination of a Layer 2 address and a Layer 3 address will enable this access from host A?
• Destination MAC: 0030.8596.DE83 Default gateway: 209.165.202.130
• Destination MAC: 0030.8596.DE82 Default gateway: 172.16.9.2
• Destination MAC: 0030.8517.44C4 Default gateway: 172.16.1.1**
• Destination MAC: 0030.8517.44C4 Default gateway: 209.165.202.130

5. Refer to the exhibit. Communication between hosts X and Y is restricted to the local network. What is the reason for this?
• The gateway addresses are broadcast addresses.
• Host Y is assigned a multicast address.
• Host X and host Y belong to different networks. **
• Host X is assigned a network address.

6. What is the result of using the clock rate 56000 command at the serial interface of the router?
• The interface is configured as a DCE device. **
• The interface timers are cleared.
• The FastEthernet interface is made to emulate a serial interface by assigning it a timing signal.
• The IP address for the serial interface is configured.

7. Which three addresses belong to the category of public IP addresses? (Choose three.)
• 127.0.0.1
• 196.1.105.6**
• 132.11.9.99**
• 10.0.0.1
• 172.16.9.10
• 46.1.1.97**

8. Which three statements are true about transport layer protocols? (Choose three.)
• TCP and UDP manage communication between multiple applications. **
• TCP retransmits the packets for which the acknowledgment is not received.
• TCP acknowledges received data. **
• UDP exchanges frames between the nodes of the network.
• TCP has no mechanism to acknowledge transmission errors.
• UDP uses windowing and sequencing to provide reliable transfer of data. **

9. Refer to the exhibit. Which logical topology describes the exhibited network?
• star
• ring
• point-to-point**
• multi-access

10. Which statement is true about the running configuration file in a Cisco IOS device?
• It affects the operation of the device immediately when modified. **
• It is stored in NVRAM.
• It should be deleted using the erase running-config command.
• It is automatically saved when the router reboots.

11. Refer to the exhibit. Host C is able to ping 127.0.0.1 successfully, but is unable to communicate with hosts A and B in the organization. What is the likely cause of the problem?
• Hosts A and B are not on the same subnet as host C.
• The IP addresses on the router serial interfaces are wrong.
• The subnet mask on host C is improperly configured. **
• The FastEthernet interface fa0/0 of router 1 is wrongly configured.

12. A host is transmitting a video over the network. How does the transport layer allow this host to use multiple applications to transmit other data at the same time as the video transmission?
• It uses error control mechanisms.
• It uses a connectionless protocol only for multiple simultaneous transmissions. **
• It uses multiple Layer 2 source addresses.
• It uses multiple port numbers.

13. Refer to the exhibit. PC1 is unable to access PC2. To troubleshoot this problem, the technician needs to confirm that the next hop interface is operational. Which default gateway address should the technician ping from PC1 to confirm this?
• 10.0.0.254
• 192.168.0.249
• 192.168.0.250**
• 10.0.1.254

14. Refer to the exhibit. Cable 1 and Cable 2 are wired for specific physical layer requirements. Which three segments use Cable 2? (Choose three.)
• Segment 1
• Segment 2**
• Segment 3
• Segment 4
• Segment 5**
• Segment 6**

15. Refer to the exhibit. Which two facts can be determined about the topology? (Choose two.)
• Three networks are needed.
• Two logical address ranges are required. **
• A single broadcast domain is present. **
• Three collision domains are present.
• Four networks are needed.

16. Refer to the exhibit. Which three statements are true about the IP configuration that is displayed? (Choose three.)
• The assigned address is a private address. **
• The PC cannot communicate with the DNS server.
• The network can have 126 hosts.
• The prefix of the computer address is /26. **
• The IP address is routable on the Internet.
• The IP address is a multicast address.

17. Which password restricts Telnet access to the router?
• enable**
• enable secret
• console
• VTY

18. Refer to the exhibit. To create the initial configuration, a network technician connected host A to the router using the connection that is shown. Which statement is true about this connection?
• It terminates at the Ethernet port of the router.
• It provides out-of-band console access. **
• It terminates at the serial interface of the router.
• It requires a Telnet client on host A to access the router.

19. Which device should be used for routing a packet to a remote network?
• access switch
• DHCP server
• hub
• router**

20. Refer to the exhibit. The serial interface of the router was configured with the use of the commands that are shown. The router cannot ping the router that is directly connected to interface serial 0/0/0. What should the network technician do to solve this problem?
• Configure the description at interface serial 0/0/0.
• Configure an IP address on interface serial 0/0/0. **
• Remove the no shutdown command at interface serial 0/0/0
• Reboot the router.

21. Refer to the exhibit. In a network, host A is sending data segments to host B. The flow control of the segments that are being exchanged is displayed. Which two statements are true about this communication? (Choose two.)
• The initial window size is determined via the two-way handshake. **
• The window size for the TCP session that is represented is initially set to 3000 bytes.
• Acknowledgment number 3001 indicates that host A will send the next segment with sequence number 3001. **
• Host B expects that the next received segment number will be 3000.
• No more acknowledgments will be exchanged.

22. Refer to the exhibit. The network administrator wants to remotely access the CLI of the router from PC1 using modem 1. Which port of the router should be connected to modem 2 to enable this access?
• console
• Ethernet
• auxiliary**
• serial

23. Which OSI layer uses a connection-oriented protocol to ensure reliable delivery of data?
• application layer
• presentation layer
• session layer
• transport layer **

24. What are two functions of the data link layer? (Choose two.)
• It segments and reorders the data. **
• It exchanges data between programs that are running on the source and destination hosts.
• It controls how data is placed onto the media. **
• It generates signals to represent the bits in each frame.
• It encapsulates each packet with a header and a trailer to transfer it across the local media.

25. Refer to the exhibit. Which list refers only to end devices?
• D,E,F,G**
• A,H,B,C
• A,D,E,F
• A,D,E,G

26. Refer to the exhibit. The diagram represents the process of sending e-mail between clients. Which list correctly identifies the component or protocol used at each numbered stage of the diagram?
• 1.MUA 2.MDA 3.MTA 4.SMTP 5.MTA 6.POP 7.MDA 8.MUA
• 1.MUA 2.POP 3.MDA 4.SMTP 5.MTA 6.MDA 7.SMTP 8.MUA
• 1.MUA 2.POP 3.SMTP 4.MDA 5.MTA 6.SMTP 7.POP 8.MUA
• 1.MUA 2.SMTP 3.MTA 4.SMTP 5.MTA 6.MDA 7.POP 8.MUA**

27. Refer to the exhibit. Host B was powered off. What change will occur in the MAC table of the switch?
The table will remain unaffected.
• The switch will remove the MAC address at Fa0/19 immediately. **
• The switch will retain the MAC address until host B is powered on again.
• The switch will rebuild the MAC table by assigning the FFFF.FFFF.FFFF address to port Fa0/19.

28. Refer to the exhibit. A technician has connected the PC to the switch using a Category 6 UTP cable. Which two statements are true about this connection? (Choose two.)
• The cable that is used is an Ethernet crossover cable.
• The transmit pin of the cable is terminated to the receive pin. **
• The maximum distance between the switch and the PC can be 100 m.
• The maximum supported bandwidth is 1000 Mb/s. **
• The Category 6 cable simulates a point-to-point WAN link and is unusable for this type of connection.

29. Refer to the exhibit. A host is using NAT to connect to the Internet. Which three IP addresses enable this connection? (Choose three.)
• 10.1.1.63
• 10.1.1.37**
• 10.1.1.39**
• 10.1.1.32
• 10.1.1.60**
• 10.1.1.2

30. Refer to the exhibit. A PC is communicating with another PC on a remote network. The two networks are connected by three routers. Which action will help to identify the path between the hosts?
• Use the ipconfig command at the host.
• Use the ipconfig/all command at the destination.
• Use the tracert command at the host. **
• Use the ping command at the destination.

31. An organization wants to create a subnet of the IP network 172.16.0.0. This subnet will accommodate 1000 hosts. Which subnet mask should be assigned to this network?
• 255.255.0.0
• 255.255.248.0**
• 255.255.252.0
• 255.255.254.0
• 255.255.255.0
• 255.255.255.128

32. Refer to the exhibit. A host is connected to hub 1. Which combination of IP address, subnet mask, and default gateway can allow this host to function in the network?
• IP address: 172.16.31.36 Subnet mask: 255.255.255.240 Default gateway: 172.16.31.35
• IP address: 172.16.31.63 Subnet mask: 255.255.255.224 Default gateway: 172.16.31.35
IP address: 172.16.31.29 Subnet mask: 255.255.255.248 Default gateway: 172.16.31.35
• IP address: 172.16.31.32 Subnet mask: 255.255.255.224 Default gateway: 172.16.31.35
• IP address: 172.16.31.29 Subnet mask: 255.255.255.240 Default gateway: 172.16.30.1
• IP address: 172.16.31.37 Subnet mask: 255.255.255.224 Default gateway: 172.16.31.35**

33. Refer to the exhibit. A technician uses the nslookup command on the PC and views the output that is displayed in the exhibit. What is the IP address of the primary domain name server configured at the host? (Choose two.)
• 192.168.1.99
• 192.168.2.100
• 10.10.10.32**
• 192.168.1.5**
• the IP address of the website resolver1.xyz.local

34. Which OSI layer offers ordered data reconstruction services?
• application layer
• network layer
• presentation layer
• session layer
• transport layer**

35. Refer to the exhibit. All devices in the network use default configurations. How many logical address ranges are required in this topology?
• 2
• 3
• 4
• 5**
• 6

36. The network administrator wants to install a private application on a server. Which range of port numbers is normally assigned to this application to make it accessible by clients?
• 0 to 255
• 49152 to 65535
• 1024 to 49151
• 0 to 1023**

37. Because of a security violation, the router password must be changed. What information can be learned from these configuration entries? (Choose two.)

• Router(config)# line vty 0 4

Router(config-line)# password arj15

Router(config-line)# login
• This configuration allows users to connect by using a modem.
• Users must specify which line, 0 or 4, they wish to connect to when making a connection.
• This configuration allows users to connect to the router via the use of the telnet command. **
• This configuration allows five users to make simultaneous connections to this router. **
• The configured password is automatically encrypted on the router.

38. Refer to the exhibit. Each media link is labeled. What type of cable should be used to connect the different devices?
• Connection 1 – rollover cable Connection 2 – straight-through cable Connection 3 – crossover cable
• Connection 1 – straight-through cable Connection 2 – crossover cable Connection 3 – rollover cable
• Connection 1 – crossover cable Connection 2 – rollover cable Connection 3 – straight-through cable
• Connection 1 – crossover cable Connection 2 – straight-through cable Connection 3 – rollover cable
• Connection 1 – straight-through cable Connection 2 – straight-through cable Connection 3 – straight-through cable**

39. Which two types of media are useful for connecting two devices separated by a distance of 500 meters? (Choose two.)
• 10 BASE-T
• 1000 BASE-TX**
• 10 BASE-2
• 1000 BASE LX
• 1000 BASE-SX **

40. Which information is used by the router to determine the path between the source and destination hosts?
• the host portion of the IP address
• the network portion of the IP address**
• host default gateway address
• the MAC address

41. Refer to the exhibit. What two facts can be determined from the session information that is displayed? (Choose two.)
• This exchange is part of the three-way handshake.
• The destination port indicates that a Telnet session has been initiated. **
• The source port does not support communication with the destination port that is listed.
• The destination port indicates that an SMTP session has been initiated.
• The protocol is a connection-oriented protocol. **

42. Refer to the exhibit. Host A is accessing multiple servers. Which combination of port number and address will uniquely identify a particular process running on a specific server?
• MAC address of the server and port number of the service
• IP address of the host and port number of the service
• MAC address of the host and port number of the service
• IP address of the server and port number of the service**

43. A network technician wants to configure an IP address on a router interface by using the ip address 192.168.1.0 255.255.255.0 command. Which prompt should the technician see when entering this command?
• Router>
• Router(config-if)# **
• Router#
• Router(config)#

44. Refer to the exhibit. Host X is unable to communicate with host Y. Which command can be run at host X to determine which intermediary device is responsible for this failure?
• telnet 192.168.1.1
• ping 192.168.1.1
• ftp 192.168.1.1
• tracert 192.168.1.1**

45. Refer to the exhibit. In a network, PC1 sends a message to PC2. The frame received at PC2 is shown. What information in this frame determines the correct destination application?
• timing and synchronization bits
• destination and source physical addresses
• destination and source logical network addresses
• destination and source process numbers**

46. An organization has been assigned network ID 10.10.128.0 and subnet mask 255.255.224.0. Which IP address range can be used for this organization?
• 10.10.128.0 to 10.10.160.255
• 10.10.128.0 to 10.10.159.255**
• 10.10.128.0 to 10.10.192.255
• 10.10.128.0 to 10.10.0.159
• 10.10.128.0 to 10.10.159.0

47. What is the effect of using the Router# copy running-config startup-config command on a router?
• The contents of ROM will change.
• The contents of RAM will change.
• The contents of NVRAM will change. **
• The contents of flash will change.

48. Which three IPv4 addresses represent valid host addresses for a subnet? (Choose three.)
• 10.1.12.79/28
• 10.1.12.113/28**
• 10.1.12.32/28
• 10.1.11.5/27**
• 10.1.11.97/27**
• 10.1.11.128/27

49. Refer to the exhibit. The NAT functionality of the router is enabled to provide Internet access to the PC. However, the PC is still unable to access the Internet. Which IP address should be changed to 209.165.201.1 to enable the PC to access the Internet?
• 192.168.1.191
• 192.168.1.101
• 192.168.1.1
• 192.168.1.254**

50. Which three statements are true about network layer addressing? (Choose three.)
• It uniquely identifies each host. **
• It assists in forwarding packets across internetworks. **
• It uses a logical 32-bit IPv4 address. **
• It is not a configurable address.
• It is a physical address.
• It identifies the host from the first part of the address.

jawaban CCNA chapter 11

Chapter 11

1. Users in the network are experiencing slow response time when doing file transfers to a remote server. What command could be issued to determine if the router has experienced any input or output errors?
• show running-config
• show startup-config
• show interfaces**
• show ip route
• show version
• show memory

2. Refer to the exhibit. A technician applies the configuration in the exhibit to a clean router. To verify the configuration, the technician issues the show running-config command in the CLI session with the router. What lines should the technician expect to see in the router output from the show running-config command?
• enable password classline console 0password ccna
• enable secret ciscoenable password classline console 0password ccna
• enable secret 5 $1$v0/3$QyQWmJyT7zCa/yaBRasJm0enable password classline console 0password ccna
• enable secret ciscoenable password 7 14141E0A1F17line console 0password 7 020507550A
• enable secret 5 $1$v0/3$QyQWmJyT7zCa/yaBRasJm0enable password 7 14141E0A1F17line console 0password 7 020507550A **


3. Refer to the exhibit. A network administrator on HostA has problems accessing the FTP server. Layer three connectivity testing was successful from HostA to the S1 interface of RouterB. Which set of commands will allow the network administrator to telnet to RouterB and run debug commands?
• RouterB(config)# enable secret class

RouterB(config)# line vty 0 4

RouterB(config-if)# login
• RouterB(config)# enable secret class

RouterB(config)# line vty 0 2

RouterB(config-vty)# password cisco

RouterB(config-vty)# login
• RouterB(config)# enable secret class

RouterB(config)# line vty 0

RouterB(config-line)# password cisco

RouterB(config-line)# login**
• RouterB(config)# enable secret class

RouterB(config)# line aux 0

RouterB(config-line)# password cisco

RouterB(config-line)# login
• RouterB(config)# enable secret class

RouterB(config)# line aux 0

RouterB(config-vty)# password cisco

RouterB(config-vty)# login

4. Refer to the exhibit. The output is shown for the show ip route command executed on Router A. What does the IP address 192.168.2.2 represent?
• Gateway for the 192.168.1.0 network
• Gateway for the 192.168.3.0 network
• IP assigned to the serial port on Router A
• IP assigned to the serial port on Router B**

5. What command is used to change the default router name to Fontana?
• Router# name Fontana
• Router# hostname Fontana
• Router(config)# name Fontana
• Router(config)# hostname Fontana**

6. The serial connection shown in the graphic needs to be configured. Which configuration commands must be made on the Sydney router to establish connectivity with the Melbourne site? (Choose three.)
• Sydney(config-if)# ip address 201.100.53.2 255.255.255.0**
• Sydney(config-if)# no shutdown**
• Sydney(config-if)# ip address 201.100.53.1 255.255.255.224
• Sydney(config-if)# clock rate 56000**
• Sydney(config-if)# ip host Melbourne 201.100.53.2

7. Refer to the exhibit. What additional command is required to allow remote access to this switch?
• NA-SW1(config-if)# no shutdown
• NA-SW1(config)# enable password password
• NA-SW1(config)# ip default-gateway address**
• NA-SW1(config-if)# description description

8. When network services fail, which port is most often used to access a router for management purposes?
AUX
Ethernet
• Console**
Telnet
SSH

9. A network administrator needs to keep the user ID, password, and session contents private when establishing remote CLI connectivity with a router to manage it. Which access method should be chosen?
• Telnet
• Console
• AUX
• SSH**

10. In a Cisco router, when do changes made to the running-configuration take effect?
• after a system restart
• as the commands are entered**
• when logging off the system
• when the configuration is saved to the startup-configuration

11. Refer to the exhibit. Which names correctly identify the CLI mode represented by the prompt for Switch-East4#? (Choose two.)
• line configuration mode
• user executive mode
• global configuration mode
• privileged executive mode**
• interface configuration mode
• enable mode**

12. Which three terms correctly define the forms of help available within the Cisco IOS? (Choose three.)
• hot keys**
• context-check
• context-sensitive**
• structured check
• command override**
• command syntax check

13. Which combination of keys would be used at the CLI prompt to interrupt a ping or traceroute process?
• Ctrl-C
• Ctrl-P
• Ctrl-R
• Ctrl-Shift-6**
• Ctrl-Z

14. Refer to the exhibit. What command will place the router into the correct mode to configure an appropriate interface to connect to a LAN?
• UBAMA# configure terminal
• UBAMA(config)# line vty 0 4**
• UBAMA(config)# line console 0
• UBAMA(config)# interface Serial 0/0/0
• UBAMA(config)# interface FastEthernet 0/1

15. On a Cisco router, which interface would be used to make the initial configuration?
• Console Port**

16. Refer to the exhibit. A student is responsible for the IP addressing, configuration and connectivity testing of the network shown in the graphic. A ping from host B to host C results in a destination unreachable but a ping from host B to host A was successful. What two reasons could account for this failure based on the graphic and partial router output for the Dallas router? (Choose two.)
• The host A is turned off.
• The Fa0/0 interface on Dallas is shutdown.
• The LAN cable is disconnected from host B.
• The S0/0/1 IP address of Dallas is improperly configured. **
• The Fa0/0 interface on Dallas is in a different subnet than host B.
• The clock rate is missing on the serial link between Dallas and NYC. **

jawaban CCNA chapter 10

Chapter 10

1. Refer to the exhibit. A student working in the lab selects a cable that is wired as shown. Which connection types can successfully be made with this cable? (Choose two.)
• connecting a PC to a router’s console port
• connecting two routers together via their fast ethernet ports**
• connecting two switches together at gigabit speeds
• connecting a PC to a switch at Gigabit Ethernet speeds
• connecting two devices with the same interface type at Fast Ethernet spee**

2. Which option identifies the primary interface which would be used for initial configuration of a Cisco router?
• AUX interface
• Ethernet interface
• serial interface
• console interface**


3. What makes fiber preferable to copper cabling for interconnecting buildings? (Choose three.)
• greater distances per cable run**
• lower installation cost
• limited susceptibility to EMI/RFI**
• durable connections
• greater bandwidth potential**
• easily terminated

4. A network administrator is required to use media in the network that can run up to 100 meters in cable length without using repeaters. The chosen media must be inexpensive and easily installed. The installation will be in a pre-existing building with limited cabling space. Which type of media would best meet these requirements?
• STP
• UTP**
• coaxial
• single-mode fiber
• multimode fiber

5. What does the term “attenuation” mean in data communication?
• loss of signal strength as distance increases**
• time for a signal to reach its destination
• leakage of signals from one cable pair to another
• strengthening of a signal by a networking device

6. How many host addresses may be assigned on each subnetwork when using the 130.68.0.0 network address with a subnet mask of 255.255.248.0?
• 30
• 256
• 2046**
• 2048
• 4094
• 4096

7. Which subnet mask would be assigned to the network address of 192.168.32.0 to provide 254 useable host addresses per subnetwork?
• 255.255.0.0
• 255.255.255.0**
• 255.255.254.0
• 255.255.248.0

8. A company is planning to subnet its network for a maximum of 27 hosts. Which subnet mask would provide the needed hosts and leave the fewest unused addresses in each subnet?
• 255.255.255.0
• 255.255.255.192
• 255.255.255.224**
• 255.255.255.240
• 255.255.255.248

9. What type of network cable is used between a terminal and a console port?
• cross-over
• straight-through
• rollover**
• patch cable

10. Which device is used to create or divide broadcast domains?
• hub
• switch
• bridge
• router**
• repeater

11. Refer to the exhibit. What destination IP address will PC1 place in the header for a packet destined for PC2?
• 192.168.1.1
• 192.168.2.1
• 192.168.2.2
• 192.168.3.1
• 192.168.3.54**

12. Refer to the exhibit. Based on the IP configuration shown, what would be the result of Host A and Host B attempting to communicate outside the network segment?
• both host A and B would be successful
• host A would be successful, host B would fail
• host B would be successful, host A would fail**
• both Host A and B would fail

13. Which three types of connectors are commonly associated with Cisco’s V.35 serial cables? (Choose three.)
• RJ 11
• DB 60**
• Winchester 15 pin**
• DB 9
• smart serial**
• RJ 45

14. Refer to the exhibit. How many subnets are required to support the network that is shown?
• 2
• 3**
• 4
• 5

15. What are three common methods for setting a UTP Ethernet port to MDI or MDIX operation? (Choose three.)
• direct configuration of the device**
• cable color code association
• cable selection and configuration
• use of cable testers to determine pinouts
• the enabling of the mechanism to electrically swap the transmit and receive pairs**
• the automatic detection and negotiating of MDI/MDIX operation of the port**

16. Which three statements are true about the role of routers in the network? (Choose three.)
• They propagate broadcasts.
• They enlarge collision domains.
• They segment broadcast domains. **
• They interconnect different network technologies. **
• Each router interface requires a separate network or subnet. **
• They maintain a common frame format between LAN and WAN interfaces.

17. Refer to the exhibit. A network administrator has decided to use packet capture software to evaluate all traffic from the student subnet on the way to the Internet. To ensure that all packets are captured, what network device should be used to connect the monitoring station to the network between R1 and R2?
• router
• hub**
• switch
• wireless access point

18. Refer to the exhibit. Assume that all devices are using default settings. How many subnets are required to address the topology that is shown?
• 1**
• 3
• 4
• 5
• 7

19. Refer to the exhibit. Which three statements are true about the exhibited topology? (Choose three.)
• Hosts B and C are in the same subnet.
• Five broadcast domains are present. **
• Host B is using a crossover cable to connect to the router. **
• Four broadcast domains are present.
• Five networks are shown. **
• Host B is using a rollover cable to connect to the router.

20. To establish a console connection from a computer to a Cisco router, which cable wiring option would be used?
• crossover cable
• straight through cable
• rollover cable**
• V.35 cable

21. Refer to the exhibit. Which three statements identify the type of cabling that would be used in the segments that are shown? (Choose three.)
• Segment 1 uses backbone cabling.
• Segment 1 uses a patch cable. **
• Segment 3 uses patch cabling.
• Segment 3 uses vertical cabling.
• Segment 3 uses horizontal cabling. **
• Segment 4 uses vertical cabling. **

22. Refer to the exhibit. A network technician has been allocated the 192.168.1.0/24 private IP address range for use in the network that shown in the exhibit. Which subnet mask would be used to meet the host requirements for segment A of this internetwork?
• 255.255.255.128
• 255.255.255.192
• 255.255.255.224**
• 255.255.255.240
• 255.255.255.248

jawaban CCNA chapter 9

3. Which of the following describe interframe spacing? (Choose two.)
• the minimum interval, measured in bit-times, that any station must wait before sending another frame.**
• the maximum interval, measured in bit-times, that any station must wait before sending another frame.
• the 96-bit payload padding inserted into a frame to achieve a legal frame size
• the 96-bit frame padding transmitted between frames to achieve proper synchronization
• the time allowed for slow stations to process a frame and prepare for the next frame. **
• the maximum interval within which a station must send another frame to avoid being considered unreachable

4. What three primary functions does data link layer encapsulation provide? (Choose three.)
• addressing**
• error detection**
• frame delimiting**
• port identification
• path determination
• IP address resolution

5. When a collision occurs in a network using CSMA/CD, how do hosts with data to transmit respond after the backoff period has expired?
• The hosts return to a listen-before-transmit mode. <—**
• The hosts creating the collision have priority to send data.
• The hosts creating the collision retransmit the last 16 frames.
• The hosts extend their delay period to allow for rapid transmission.

6. What are three functions of the upper data link sublayer in the OSI model? (Choose three.)
• recognizes streams of bits
• identifies the network layer protocol. **
• makes the connection with the upper layers. **
• identifies the source and destination applications
• insulates network layer protocols from changes in physical equipment. **
• determines the source of a transmission when multiple devices are transmitting

7. What does the IEEE 802.2 standard represent in Ethernet technologies?
• MAC sublayer
• Physical layer
• Logical Link Control sublayer**
• Network layer

8. Why do hosts on an Ethernet segment that experience a collision use a random delay before attempting to transmit a frame?
• A random delay is used to ensure a collision-free link.
• A random delay value for each device is assigned by the manufacturer.
• A standard delay value could not be agreed upon among networking device vendors.
• A random delay helps prevent the stations from experiencing another collision during the transmission.**

9. Refer to the exhibit. Which option correctly matches the frame field type with the contents that frame field includes?
• header field – preamble and stop frame**
• data field – network layer packet
• data field – physical addressing
• trailer field – FCS and SoF

10. Host A has an IP address of 172.16.225.93 and a mask of 255.255.248.0. Host A needs to communicate with a new host whose IP is 172.16.231.78. Host A performs the ANDing operation on the destination address. What two things will occur? (Choose two.)
• Host A will change the destination IP to the IP of the nearest router and forward the packet.
• Host A will broadcast an ARP request for the MAC of its default gateway.
• A result of 172.16.225.0 will be obtained.
• Host A will broadcast an ARP request for the MAC of the destination host. **
• A result of 172.16.224.0 will be obtained.
• A result of 172.16.225.255 will be obtained. **

11 Which of the following is a drawback of the CSMA/CD access method?
• Collisions can decrease network performance. **
• It is more complex than non-deterministic protocols.
• Deterministic media access protocols slow network performance.
• CSMA/CD LAN technologies are only available at slower speeds than other LAN technologies.

12. Ethernet operates at which layer of the TCP/IP network model?
• application
• physical
• transport
• internet
• data link
• network access **

13. What is the primary purpose of ARP?
• translate URLs to IP addresses
• resolve IPv4 addresses to MAC addresses**
• provide dynamic IP configuration to network devices
• convert internal private addresses to external public addresses

14. Refer to the exhibit. The switch and workstation are administratively configured for full-duplex operation. Which statement accurately reflects the operation of this link?
• No collisions will occur on this link. **
• Only one of the devices can transmit at a time.
• The switch will have priority for transmitting data.
• The devices will default back to half duplex if excessive collisions occur.

15. Refer to the exhibit. Host_A is attempting to contact Server_B. Which statements correctly describe the addressing Host_A will generate in the process? (Choose two.)
• A packet with the destination IP of Router_B.
• A frame with the destination MAC address of Switch_A.
• A packet with the destination IP of Router_A.
• A frame with the destination MAC address of Router_A. **

• A packet with the destination IP of Server_B. **
• A frame with the destination MAC address of Server_B.

16 Which statements correctly describe MAC addresses? (Choose three.)
• dynamically assigned
• copied into RAM during system startup**
• layer 3 address
• contains a 3 byte OUI**
• 6 bytes long**
• 32 bits long

17. Which two features make switches preferable to hubs in Ethernet-based networks? (Choose two.)
• reduction in cross-talk
• minimizing of collisions**
• support for UTP cabling
• division into broadcast domains**
• increase in the throughput of communications

18. What are the two most commonly used media types in Ethernet networks today? (Choose two.)
• coaxial thicknet**
• copper UTP
• coaxial thinnet
• optical fiber
• shielded twisted pair**

19. Convert the binary number 10111010 into its hexadecimal equivalent. Select the correct answer from the list below.
• 85
• 90
• BA**
• A1
• B3
• 1C

20. After an Ethernet collision, when the backoff algorithm is invoked, which device has priority to transmit data?
• the device involved in the collision with the lowest MAC address
• the device involved in the collision with the lowest IP address
• any device in the collision domain whose backoff timer expires first**
• those that began transmitting at the same time