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Zorluk: ZorNetwork Host Services and Server Roles

A network technician is troubleshooting connectivity issues at a newly configured remote office. Several workstations display 'Limited or No Connectivity' notifications. Executing `ipconfig /all` on an affected client yields an IPv4 address of 169.254.112.45169.254.112.45, a subnet mask of 255.255.0.0255.255.0.0, and an empty default gateway entry. When a technician assigns a valid static IP address, subnet mask, gateway, and DNS server to a workstation, full internet and internal network connectivity is immediately restored. Which server role is failing to supply automated network parameters, and which protocol ports must be allowed through local firewalls to enable this service?

  1. DHCP server using UDP ports 67 and 68Cevap
  2. B
    DNS server using TCP and UDP port 53
  3. C
    DHCP server using TCP ports 53 and 80
  4. D
    Proxy server using UDP ports 169 and 254

Cevap

The DHCP server service operating on UDP ports 67 and 68 is failing to reach the clients or is blocked by network filters.
An IP address in the range of 169.254.0.1 through 169.254.255.254 indicates that the operating system engaged Automatic Private IP Addressing (APIPA) due to an inability to contact a Dynamic Host Configuration Protocol (DHCP) server. DHCP handles automated allocation of IP addresses, subnet masks, default gateways, and DNS server addresses across a network. DHCP communicates using UDP port 67 on the server side and UDP port 68 on the client side.

Adım Adım Çözüm

1
Analyze the client IP configuration output
The IP address 169.254.112.45169.254.112.45 falls within the Automatic Private IP Addressing (APIPA) block (169.254.0.1169.254.0.1 to 169.254.255.254169.254.255.254).
Client operating systems generate an APIPA address automatically when dynamic address allocation fails.
2
Identify the failing server infrastructure role
The DHCP (Dynamic Host Configuration Protocol) server is responsible for leasing IP addresses, subnet masks, default gateways, and DNS settings.
Since static IP configuration immediately fixes the problem, the network hardware is functional, confirming that the DHCP server or DHCP relay mechanism is inaccessible.
3
Verify protocol port requirements for the failing service
DHCP relies on UDP port 67 for the server listener and UDP port 68 for client communications.
Firewall or ACL rules blocking UDP ports 67/68 prevent DHCPDISCOVER packets from reaching the DHCP server.

Anahtar Kavram

Network Host Services and Server Roles (DHCP vs DNS and APIPA Diagnosis)
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