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Zorluk: ZorIP Addressing and Network Configuration

A system administrator manually assigns a static IPv4 configuration to a workstation on a corporate LAN subnet. The technician inputs the following parameters into the network adapter settings:

- IP Address: 192.168.1.127192.168.1.127
- Subnet Mask: 255.255.255.192255.255.255.192
- Default Gateway: 192.168.1.65192.168.1.65

After applying these settings, the workstation cannot communicate with any host on the local subnet or the default gateway. Which of the following best explains why this static network configuration is failing?

  1. The assigned IP address is the direct broadcast address for the subnet and cannot be used as a valid host address.Cevap
  2. B
    The default gateway IP address resides on a different subnet boundary than the workstation IP address.
  3. C
    The workstation automatically reverted to an APIPA address because the local DNS server failed to validate the static lease.
  4. D
    The configuration fails because port 67 was assigned as the primary DNS server instead of port 53 on the host adapter.

Cevap

The assigned IP address is the direct broadcast address for the configured subnet and cannot be assigned to an individual host interface.
With a subnet mask of 255.255.255.192255.255.255.192 (/26/26), the network is divided into subnets of 6464 IP addresses each. For the subnet starting at 192.168.1.64192.168.1.64, the valid host address range is 192.168.1.65192.168.1.65 through 192.168.1.126192.168.1.126. The address 192.168.1.127192.168.1.127 is the directed broadcast address for this subnet and is rejected by the TCP/IP stack for host interface assignment.

Adım Adım Çözüm

1
Determine the block size from the subnet mask
Subnet mask 255.255.255.192255.255.255.192 is a /26/26 prefix. The block size per subnet is 256−192=64256 - 192 = 64.
Calculating the block size identifies the network and broadcast boundaries for subnets in the fourth octet.
2
Identify subnet boundary for the gateway 192.168.1.65192.168.1.65
Subnets start at 192.168.1.0192.168.1.0, 192.168.1.64192.168.1.64, 192.168.1.128192.168.1.128, etc. The host's subnet is 192.168.1.64/26192.168.1.64/26.
The gateway address 192.168.1.65192.168.1.65 falls into the 192.168.1.64/26192.168.1.64/26 subnet range.
3
Calculate valid host range and broadcast address
Subnet ID: 192.168.1.64192.168.1.64. Valid host IP range: 192.168.1.65192.168.1.65 to 192.168.1.126192.168.1.126. Broadcast IP: 192.168.1.127192.168.1.127.
The last address in a subnet range (192.168.1.127192.168.1.127) is reserved for broadcast traffic.
4
Evaluate the assigned workstation IP 192.168.1.127192.168.1.127
Assigning 192.168.1.127192.168.1.127 attempts to assign the broadcast address to a single NIC, causing protocol stack communication errors.
Broadcast addresses cannot be assigned as unicast host IP addresses.

Anahtar Kavram

Subnet Mask Block Sizes and Broadcast Address Reservations
Tahmini Süre:2m 0s
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IP Addressing and Network Configuration

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