Examkin

Soru

Zorluk: Çok zorIPv4 Addressing and Subnetting

A network infrastructure engineer is dividing the IPv4 address space 172.28.144.0/20172.28.144.0/20 using Variable Length Subnet Masking (VLSM). The subnets must be allocated contiguously starting from the lowest available network address in descending order of host requirements without wasting address blocks between subnets:

1. Subnet A: Requires 450450 usable host IP addresses.
2. Subnet B: Requires 190190 usable host IP addresses.
3. Subnet C: Requires 6060 usable host IP addresses.

What is the broadcast IP address of Subnet C?

Cevap: 172.28.147.63

Cevap

172.28.147.63
Subnet C begins at 172.28.147.0172.28.147.0 after allocating a /23/23 (512512 addresses) for Subnet A and a /24/24 (256256 addresses) for Subnet B. A /26/26 prefix accommodates 6060 hosts (6262 usable, block size of 6464), making the address range 172.28.147.0172.28.147.0 through 172.28.147.63172.28.147.63. The last address in this subnet block (172.28.147.63172.28.147.63) serves as the broadcast IP address.

Adım Adım Çözüm

1
Determine prefix length and block size for Subnet A (450 usable hosts)
Subnet A requires 99 host bits (29−2=5102^9 - 2 = 510 usable IPs), giving a CIDR mask of /23/23 (32−932 - 9) and a block size of 512512 addresses (292^9). Allocated range: 172.28.144.0172.28.144.0 to 172.28.145.255172.28.145.255.
Subnets must be allocated in descending order of required hosts.
2
Determine prefix length, block size, and range for Subnet B (190 usable hosts)
Next available start IP is 172.28.146.0172.28.146.0. Subnet B requires 88 host bits (28−2=2542^8 - 2 = 254 usable IPs), giving a CIDR mask of /24/24 (32−832 - 8) and a block size of 256256 addresses (282^8). Allocated range: 172.28.146.0172.28.146.0 to 172.28.146.255172.28.146.255.
Subnet B must immediately follow Subnet A contiguously.
3
Determine prefix length, block size, and broadcast address for Subnet C (60 usable hosts)
Next available start IP is 172.28.147.0172.28.147.0. Subnet C requires 66 host bits (26−2=622^6 - 2 = 62 usable IPs), giving a CIDR mask of /26/26 (32−632 - 6) and a block size of 6464 addresses (262^6). Network ID: 172.28.147.0/26172.28.147.0/26. Broadcast address: 172.28.147.63172.28.147.63.
The broadcast address is the last IP in the /26/26 block (172.28.147.0+63172.28.147.0 + 63).

Anahtar Kavram

Variable Length Subnet Masking (VLSM) contiguous allocation
Bu soruyu puanla

Konular

IPv4 Addressing and Subnetting

Bu konudan daha fazla soru