Question Five
(a) A host determines its IP address during the hoot-up process either from a configuration file stored in the local hard disk of The system (static configuration) or using a network protocol. Mention three protocols [6 Marks]
(5) Euphemis oversees a tietwork with six subnets. An NT workstation computer user on the last subnet complains that while he can connect to other local servers, he cannot connect to NT server computer on the first subnet. Other users on the last subnet have no sach trouble. Euphemis is advised to run IPCONFIG on his computer which displays the following
Ethernet adapur 00:30.91:22:41:34
IP address 129.164.223.11
Soboet mask 255.255.224.0
Default gateway 129.164.224.1
what could be the reason (Explam biely
114 Marix
The Correct Answer and Explanation is :
(a) Protocols for Dynamic IP Address Configuration
During the boot-up process, a host can dynamically determine its IP address using the following network protocols:
- Dynamic Host Configuration Protocol (DHCP): DHCP is a network management protocol used on IP networks to automatically assign IP addresses and other configuration parameters to devices. It eliminates the need for manual configuration by providing a centralized system for IP address allocation. citeturn0search0
- Bootstrap Protocol (BOOTP): BOOTP is an older protocol that allows a diskless workstation to discover its own IP address, the address of a server on the network, and the name of a file to be loaded into memory to boot the machine. While largely superseded by DHCP, BOOTP laid the groundwork for dynamic IP address assignment.
- IPv6 Stateless Address Autoconfiguration (SLAAC): In IPv6 networks, SLAAC enables devices to self-configure an IP address without the need for a server. By using information from router advertisements, a device can generate its own IP address and configure other network settings.
(b) Analysis of Connectivity Issue
The NT workstation is configured with the following network settings:
- IP Address: 129.164.223.11
- Subnet Mask: 255.255.224.0
- Default Gateway: 129.164.224.1
The subnet mask 255.255.224.0 corresponds to a prefix length of /19, which means the first 19 bits of the IP address denote the network portion. This subnet mask divides the IP address space into subnets, each capable of hosting a range of IP addresses.
To determine the network address for the workstation:
- Convert the IP Address and Subnet Mask to Binary:
- IP Address (129.164.223.11): 10000001.10100100.11011111.00001011
- Subnet Mask (255.255.224.0): 11111111.11111111.11100000.00000000
- Perform a Bitwise AND Operation:
- Network Address: 10000001.10100100.11000000.00000000
- In Decimal: 129.164.192.0
This calculation indicates that the workstation resides in the 129.164.192.0/19 subnet, which includes IP addresses from 129.164.192.1 to 129.164.223.254.
The default gateway, 129.164.224.1, falls outside this range, as it belongs to the 129.164.224.0/19 subnet (covering 129.164.224.1 to 129.164.255.254). This discrepancy means the workstation cannot communicate with the default gateway, leading to connectivity issues with devices outside its local subnet.
Recommendation:
To resolve this issue, the default gateway should be set to an IP address within the workstation’s subnet. For instance, assigning the default gateway to an address like 129.164.192.1 would align it with the workstation’s network, facilitating proper routing and connectivity to other subnets.
Alternatively, if the default gateway’s IP address must remain as 129.164.224.1, adjusting the workstation’s subnet mask to 255.255.192.0 (/18) would expand the network range to include both the workstation’s IP address and the default gateway. However, this change could have broader implications for network segmentation and should be implemented with caution.
In summary, ensuring that the default gateway resides within the same subnet as the workstation is crucial for proper inter-subnet communication. Misconfigurations in subnetting can lead to significant connectivity challenges, as observed in this scenario.