Contoh Soal Subnetting 1.SOAL MENANYAKAN SUBNETMASK DENGAN PERSYARATAN JUMLAH HOST ATAU SUBNET Soal yang menanyakan subnetmask apa yang sebaiknya digunakan dengan batasan jumlah host atau subnet yang ditentukan dalam soal. Untuk menjawab soal seperti ini kita gunakan rumus menghitung jumlah host per subnet, yaitu 2y - 2, dimana y adalah banyaknya binari 0 pada oktet terakhir subnetmask. Dan apabila yang ditentukan adalah jumlah subnet, kita menggunakan rumus 2x (cara setelah 2005) atau 2x - 2 (cara sebelum 2005), dimana x adalah banyaknya binari 1 pada oktet terakhir subnetmask. • Soal: A company is planning to subnet its network for a maximum of 27 hosts. Which subnetmask would provide the needed hosts and leave the fewest unused addresses in each subnet? Jawab: Karena kebutuhan host adalah 27, kita tinggal masukkan ke rumus 2y - 2, dimana jawabannya tidak boleh kurang dari (atau sama dengan) 27. Jadi 2y - 2 >= 27, sehingga nilai y yang tepat adalah 5 (30 host). Sekali lagi karena y adalah banyaknya binari 0 pada oktet terakhir subnetmask, maka kalau kita susun subnetmasknya menjadi 11111111.11111111.11111111.11100000 atau kalau kita desimalkan menjadi 255.255.255.224. Itulah jawabannya • Soal: You have a Class B network ID and need about 450 IP addresses per subnet. What is the best mask for this network? Jawab: 2y - 2 >= 450. Nilai y yang tepat adalah 9 (510 host). Jadi subnetmasknya adalah: 11111111.11111111.11111110.00000000 atau kalau didesimalkan menjadi 255.255.254.0 168.168 223.255. 24.17. The internetwork in the exhibit has been assigned the IP address 172.168.255.168.168.255.166 … 223.161 … 223.175 … … … … Subnet Host Pertama Host Terakhir Broadcast .167 223.17.167 adalah alamat broadcast.20.17.0. 248. Nilai y yang paling tepat adalah 10 (1022 host).0.2 >= 850.168. Kalau kita susun seperti yang dulu kita lakukan di penghitungan subnetting adalah seperti di bawah.168.168. … 223. 16.167/29? Jawab: Subnetmask dengan CIDR /29 artinya 255. yaitu 160 dan 168. alias urutan subnetnya adalah kelipatan 8 yaitu 0. Blok subnet= 256-248 = 8. Jadi subnetmasknya adalah 11111111. SOAL MENGIDENTIFIKASI JENIS ALAMAT IP Soal mengidentifikasi jenis alamat IP bisa kita jawab dengan menghitung blok subnet dan mencari kelipatannya blok subnet yang paling dekat dengan alamat IP yang ditanyakan. jadikan itu rujukan karena kalau kita ambil terkecil ada kemungkinan kebutuhan host yang lebih besar tidak tercukupi.11111111. Dari situ ketahuan bahwa 223.0 2. What would be the appropriate subnet mask to maximize the number of networks available for future growth? Jawab: Cari jumlah host per subnet yang paling besar.168.160 … 223.17.17.168. • Soal: Which type of address is 223. 8.11111100.17. Jadi untuk soal ini 2y .17. 32.17.00000000 atau 255.169 223.174 223. Tidak perlu mencari semu subnet (kelipatan blok subnet).252. ….17. yang penting kita cek kelipatan 8 yang paling dekat dengan 167 (sesuai soal).17.• Soal: Refer to the exhibit.168. 248. Dari sini kita tahu bahwa isian netmask di host adalah berbeda. Apakah alamat IP tersebut masuk diantara host pertama dan terakhir.64 dan bukan 198. Apakah subnetmask yang digunakan di host dan di router sudah sama 2.18.166. 224).18. 86.32. The host configuration is shown in the exhibit. karena biasa digunakan alamat host pertama. masuk di subnet 198.32. 64.18.166. Biasanya alamat host pertama digunakan untuk alamat IP di router untuk subnet tersebut • Soal: Host A is connected to the LAN.166. …. Hanya alamat IP hostnya salah karena 198.3. Sudah benar ini artinya: 1. jadi salah setting di netmask.65 masuk di alamat subnet 198.224.255. but it cannot connect to the Internet. Yang kedua blok subnet = 256-224 = 32. 128. Alamat gateway sudah benar. What are the two problems with this configuration? Jawab: CIDR /27 artinya netmask yang digunakan adalah 255. gateway dan netmasknya apakah sudah bener.18. 32. Artinya di bawah Router 1. jadi subnetnya adalah kelipatan 32 (0.255. . Perlu dicatat bahwa alamat subnet dan broadcast tidak bisa digunakan untuk alamat IP host 3.166. SOAL MENGIDENTIFIKASI KESALAHAN SETTING JARINGAN Teknik mengerjakan soal yang berhubungan dengan kesalahan setting jaringan adalah kita harus menganalisa alamat IP. 5. Tidak perlu kita list semuanya.64.64. … 200.79 200.0 dan 172. Teknik mengerjakan soal yang menanyakan alamat subnet dan host yang valid dari suatu subnetmask adalah dimulai dengan mencari blok subnetnya.0 adalah seperti di bawah. 16. blok subnet kita “goyang” di oktet ke 3. netmasknya adalah kelipatan 16 (0. host pertama.10.16.72.81 200.254 … … … Subnet Host Pertama Host Terakhir Broadcast … 172.94 200.16.95 … … … … Subnet Host Pertama Host Terakhir Broadcast .16.64.16.0/21?Jawab: CIDR /21 berarti 255. baik di ujian CCNA akademi (CNAP) atau CCNA 604-801.72.0 172. 40.66.5. Jadi pertanyaan bisa dijawab bahwa 172.10.16.16.10.10.248 = 8.16. serta yang terakhir mencocokkan susunan alamat tersebut dengan soal ataupun jawaban yang dipilih.10.66.68/28?Jawab: CIDR /28 berarti 255.255 … • Soal: What is the subnetwork address for a host with the IP address 200.4.248. netmasknya adalah kelipatan 8 (0.5.1 … 172.71.16. 48.10.5.10.64.5.255.10. • Soal: What is the subnetwork number of a host with an IP address of 172.5.255 172.254 172.16. 32.5.16. 80 ….68 masuk di alamat subnet 200. Blok subnet = 256240 = 16. 32. 64. ….16. yaitu 64 dan 72.71.0.255.0 … 172. Kelipatan 16 yang paling dekat dengan 68 (sesuai soal) adalah 64 dan 80.5.255.72.64 … 200. Blok subnet = 256.1 172. host terakhir dan broadcastnya.0 … 172.78 … 200. Jadi alamat IP 200.64.79. menyusun alamat subnet. 24. 240). 48. 8.10.16.10. kita hanya perlu cari kelipatan 8 yang paling dekat dengan 66 (sesuai dengan soal).240. 248) dan karena ini adalah alamat IP kelas B.16.79.0 itu masuk di subnet 172. Jadi susunan alamat IP khusus untuk subnet 172.65 … 200. 16.5.5.80 200. SOAL MENGIDENTIFIKASI ALAMAT SUBNET DAN HOST YANG VALID Termasuk jenis soal yang paling banyak keluar.10.5. 159.224.0 … … … 172.159.255 … Dari sini berarti kita bisa lihat bahwa alamat subnet berikutnya pasti 172.5. Amiin . Jadi kalau kita gambarkan seperti di bawah: … … … 172. Kok tahu kalau letak 224 di oktet ketiga? Ya karena yang kita kurangi (”goyang”) tadi adalah oktet ketiga.16.16. sholat yang khusuk dan baca lagi artikel ini pelan-pelan Insya Allah akan paham.255?Jawab: Teknik paling mudah mengerjakan soal diatas adalah dengan menganggap 172.160. Saya coba sajikan secara bertahap soal-soal tersebut di sini.0.159. Subnet Host Pertama Host Terakhir Broadcast … 172. Artinya subnetmasknya adalah 255.255 adalah satu blok subnet.16.0 … … … … Masih bingung? Atau malah tambah pusing? Tarik nafas dulu.16. istirahat cukup. SOAL-SOAL LAIN YANG UNIK Selain 4 pola soal diatas. terus otomatis juga ketahuan subnetmasknya karena rumus blok subnet adalah 256-oktet terakhir netmask.0 … … … Subnet Host Pertama Host Terakhir Broadcast … 172.160.16.0.0 dan 172.16. kadang muncul soal yang cukup unik.255.128.128.16.16.128. karena rumus alamat broadcast adalah satu alamat sebelum alamat subnet berikutnya. sepertinya sulit meskipun sebenarnya mudah.255 172. Nah sekarang jadi ketahuan blok subnetnya adalah 160-128 = 32 (kelipatan 32).16. sambil saya analisa lagi soal-soal subnetting yang lain lagi • Soal: Which combination of network id and subnet mask correctly identifies all IP addresses from 172.16.0 through 172.128.159. 2005 Todd Lammle.168.net Sumber: Cisco Networking Academy Program.248 2.45 Gateway .255.192.0 d. Sybex.14 Gateway . CCNA Study Guide 5th Edition.255.240.192.255.1.65 http://romisatriawahono.168.192.168.SOAL LATIHAN SUBNETTING http://romisatriawahono. 2005 Todd Lammle. Sybex. Refer to the exhibit.70 Gateway .1. 255.192. Address . Cisco Press.192.192.168.192. 255.192.254.33 b.192.255. Which two addressing scheme combinations are possible configurations that can be applied to the host for connectivity? (Choose two.1.) a.1.1.32 Gateway . 255.net Sumber: Cisco Networking Academy Program. 255.0 b.192. Address . 255. Address .0 c.1.168. CCNA 1 and 2 Companion Guide.63 Gateway .255.1. 255. Address .168.33 c.33 d. CCNA 1 and 2 Companion Guide.1.168.168.1. Host A is being manually configured for connectivity to the LAN.255.248.65 f.168. Cisco Press.255. 2005. 1 Soal Subnetting 1.192.192. Address .0 e.168.255.1.255. A company has the following addressing scheme requirements: -currently has 25 subnets -uses a Class B IP address -has a maximum of 300 computers on any network segment -needs to leave the fewest unused addresses in each subnet What subnet mask is appropriate to use in this company? a. 2 .82 Gateway .1.65 e. 2005. CCNA Study Guide 5th Edition.128 f.168. Address .1.168. 31.255.128. broadcast address d.0 through 172.0 e.168.167/29? a.16.255.31. 172.4.192.166 with a mask of 255.31.192 5.160.255? a.128.0 e.16. 172.168.128.255.0 d.31. 172.0 and 255. A NIC of a computer has been assigned an IP address of 172.192.) a. 255.0 b.31. 172.192. 172. 172. Which combination of network id and subnet mask correctly identifies all IP addresses from 172.3.0 d.255.255.192.255.255. 172.254.0 and 255.0 c. 172.248. 14 networks / 14 hosts c. multicast address c.224.0. To which subnet does the IP address belong? a.0 b.0. 255.16.0 and 255.0 and 255.192. 6 networks / 32 hosts b.0.128.16.17. What is the correct number of usable subnetworks and hosts for the IP network address 192. 14 c. 172.0 and 255. 30 networks / 6 hosts d.252.16.31.0 c. Company XYZ uses a network address of 192.0 d. 255.99.168.31.128.0. It uses the mask of 255.0 c.0. 172. subnetwork address 7. What is the maximum number of usable hosts in each subnet? a. host address b.224 to create subnets. 255.255. 255.0.16.255.16.0.224 b. 255. 6 b.255.0 f.0 subnetted with a /29 mask? a.255. 62 networks / 2 hosts 8.255.255. Which subnet masks would be valid for a subnetted Class B address? (Choose two.255.224.160 f.159.255. 30 . 172.0. Which type of address is 223.128.248.192 6.248 4.0 e. 32. 255.32.210.255.32.252 11.255.16.252.255.net Sumber: Cisco Networking Academy Program. 172.255.255. 255.254. 172.255.0 d.240 d. Sybex.0 c. 255.255.0 .255.255. 172. to which network does the host belong? a. What is the appropriate subnet mask for the newly created subnetworks? a. 255.255. Given a host with the IP address 172.255.32. 255.255.32. What is the correct subnet mask to use with the network configuration? a.240 e.65.255. What is the subnetwork number of a host with an IP address of 172. An IP network address has been subnetted so that every subnetwork has 14 usable host IP addresses.255. 255.240.13 and a default subnet mask.0 c.0 b.16. 255.16.224 d.192 c. A company is planning to subnet its network for a maximum of 27 hosts. 255. CCNA Study Guide 5th Edition.255.255. 255.32.255.255.254. 2005.248 10.0 b.255. 255.255.32 c.192 12.255.0.255.0 13.65.42.16.16.0/22? a. 255. 62 http://romisatriawahono.255.248 e. 172. 172.255.208.0 d. 255. 172.0 e. 255.65.128 f. 172. Cisco Press. 172. 3 9.255.0 e.107. Which subnet mask would provide the needed hosts and leave the fewest unused addresses in each subnet? a.255. A company is using a Class B IP addressing scheme and expects to need as many as 100 networks.d. 172.0.0 b. 255.255.0 b.0 d.224 c.128 b.255. 2005 Todd Lammle. 255. CCNA 1 and 2 Companion Guide. 255.255.16. 5.5. 8 subnets.5. 115.64.10. 172.0 18.16.32 b. 30 hosts each b. 30 hosts each e. The network address of 172. What mask will you assign using a Class B network address? a.0/22? (Choose three. 8 subnets. 4 15. 115.16.255 e.0.255. 115.10.0 b. CCNA 1 and 2 Companion Guide. 7 subnets.0 .252 b. Sybex. 172.5. Cisco Press.0/21? a.255.4. 2005.16.12.10.) a.36. 2005 Todd Lammle.16. 8190 hosts each 17. 172.3.64.48.66.64.64.16. 2046 hosts each f.254.255. 2046 hosts each c. 200.64.68/28? a.8.64 c.128 http://romisatriawahono.5.255. CCNA Study Guide 5th Edition. You need 500 subnets.255. 115.0/19 provides how many subnets and hosts? a.14 Which of the following IP addresses fall into the CIDR block of 115. 200.64.255.128 c. What is the subnetwork address for a host with the IP address 200.7. 7 subnets.6.64. each with about 100 usable host addresses per subnet. 8190 hosts each d. 255. 7 subnets.128 f. 115.16.5. 255. 172.0 16. What is the subnetwork number of a host with an IP address of 172.0 d.255 d.10.64 d.255.net Sumber: Cisco Networking Academy Program.64. 200. 200. 115. 8 subnets. 255.10.56 b.0 d.0 c.0. 255.32 c. 255.252.255. 255.16.16.255. Which of the following masks will support the business requirements? (Choose two. 172.0 c. 2005.128 c.26 255.248.255.0. 5 22.168.0.255.19.0 b. 255. Which of the following should you assign to the server? a.0. 172.255.0. 192.19.net Sumber: Cisco Networking Academy Program.33 255. 192.255.25. 255.255.248 e. 255.0 if you needed about 100 subnets with about 500 hosts each? a.0.254.255.255. You need to configure a server that is on the subnet 192.248. 192. The internetwork in the exhibit has been assigned the IP address 172.31 255.255. what would be the valid subnet address of this host? a.0 c.19.255.252. 172.0 c.255. 255.255.240 c. 192.252.255. 255.255. The router has the first available host address.34 255.16. What would be the appropriate subnet mask to maximize the number of networks available for future growth? a.96.20.0 b.0 d. If an Ethernet port on a router were assigned an IP address of 172.168.0 23. Sybex.240.168.24/29.255.0 http://romisatriawahono.0 255.224 e.0 b.168.240 21. 255. You need a minimum of 300 subnets with a maximum of 50 hosts per subnet.248 d. 255. Refer to the exhibit.1/25. What mask would you assign to the network ID of 172.16.0 b.255. 172. 255.0 b. 255. 2005 Todd Lammle.19.0 .0 20.19.0 d.255. 172.255.255. 255.255.168.255.16.255.224. CCNA Study Guide 5th Edition. 255.112.19.16.255.255.) a.192 f.255. 192.19.0 d.0 e. CCNA 1 and 2 Companion Guide. 255.112.255.0 d.16.168.255. Cisco Press.255.128. Sybex.0 24.255.16.1 255.255. The host configuration is shown in the exhibit.20.63 b.255.56 d. b. 1024 b.248. 4096 e.16.16. 255.93 c. 216.255.15.net Sumber: Cisco Networking Academy Program.1 255.1 255.255. 90.0. The host IP address is on a different network from the Serial interface of the router.87 e. 143.170.254.192 27.10. but it cannot connect to the Internet.17. The default gateway is on a different network than the host.16.0. 200. CCNA Study Guide 5th Edition. CCNA 1 and 2 Companion Guide.255.16.0/22.187.0 b.254.254. e.16.255.255.18.0 28.16. 2005 Todd Lammle.255.244. 172. 255.0 c. 6 26. What are the two problems with this configuration? (Choose two.17. 2005.0 c.1/20. 172.255.18. Host A is connected to the LAN.0 d.255. 172.0 d.255.159 f. How many hosts can be accommodated on the Ethernet segment? a.252 b. . d.255.) a. 255. Cisco Press.0 25 Your router has the following IP address on Ethernet0: 172. 2046 c. Which of the following are valid hosts? (Choose three.45.255. 255.) a. c. 192.0 f.240 e.1 255. What is the best mask for this network? a.168.240. 172.66.112. 255.255.16. You have a /27 subnet mask. 172. The default gateway is a network address. 4094 d. 172.e.11. The host subnet mask is incorrect. 11. You have a Class B network ID and need about 450 IP addresses per subnet.115.240. The host is not configured for subnetting.16.1 255.255 255. Which are valid host addresses? a. 8190 http://romisatriawahono.252.16. You have a network with a subnet of 172. Cisco Router. Hendra Wijaya. Module CCNA 1 Chapter 9-10. 2004. 2. CCNA Study Guide 5th Edition. Sybex. Dikutip dari :http://romisatriawahono. Cisco Systems. Cisco Networking Academy Program (CNAP). 3.REFERENSI 1. Elex Media Komputindo. 2005. Todd Lamle.net .