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Advanced Subnetting Techniques for Building
Secure Modern Networks |
Introduction
Enterprise networks of the present day should be planned to
include security, scalability, and manageability. Subnetting and appropriate
configuration of windows server roles are two important elements that can make
network architecture secure. Subnetting further breaks down large networks into
smaller and manageable parts and windows server roles are important to offer
the necessary services that ensure security policies, identities, and protect
data. These factors combined create the core of a properly designed, safe
infrastructure that can help counter internal and external threats.
The reality of Subnetting and its
advantages
The subnetting is a process of subdivision of a large IP
network into small networks that are logically separated into subnets. The
division assists in minimizing broadcast traffic, enhancing the performance of
the network, and the establishment of limits that can support security.
Traditional simple flat networks leave all their devices within the same
broadcast domain, thereby exposing those devices to attacks, like the ARP
spoofing, broadcast storming and lateral expansion by rogue hosts.
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Subnetting reduces the size of the broadcast
domain, keeping the internal traffic contained within a set number of segments
and not being exposed to the whole network and avoidable.
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Security-wise, subnetting imposes isolation of
devices in terms of purpose, sensitivity or department.
·
As an illustration, servers containing
confidential data can be assigned a separate subnet and not connected to
desktops of users or systems that are open to the outside world.
·
Such segmentation is useful to implement
security policies better since administrators are able to use access control
lists, firewall rules, and VLAN settings restricting communications between
network segments.
·
Subnetting a network decreases the number of
avenues that can be exploited by an attacker since networks have only a limited
number of subnets.
Subnetting to Efficient Network
Management
Besides security, subnetting helps in logical arrangement
and efficiency in the allocation of the IP addresses. As the networks increase,
random assignment of devices in one IP range becomes chaotic. Subnetting
divides the devices into smaller and predictable units, which makes the process
of troubleshooting and monitoring the network more organized. Specialized
subnets such as printers, wireless access points and servers, VoIP systems
allow the administrator to set specific policies depending on the needs and
level of security of each type of device.
Subnetting is also very important in routing efficiency. The
router takes the form of subnet structures to identify the optimal route to be
used in the network traffic. Hierarchical subnetting plan will decrease the
size of the routing table, prevent routing loops, and reduce convergence of
routes. This efficiency is again indirectly related to security since they
enhance resilience and stability of the network to the load or when there is an
attack.
Access Control and Subnetting
Granting access control on a granular basis is one of the
greatest security benefits of subnetting. Subnets are used together with
firewalls or layer 3 switches as security zones where the communication between
devices is restricted unless explicitly permitted. Protected subnets with
sensitive servers like domain controllers, database servers and HR systems can
be situated.
The strategy complies with the concepts of Zero Trust
whereby there is no blanket access assigned to any device and security
boundaries are implemented at various levels. Subnet-based access control also
slows attackers in case of breach, and they have a focus on their ability to
laterally traverse the network.
Roles and Functions in Secure Network
Infrastructure
Whereas subnetting guarantees the network the infrastructure
level, windows server roles guarantee the network the system and identity
level. Windows server has a large variety of roles that offers essential
services needed to ensure protection of secure operations.
Active Directory Domain Services
Most enterprise networks use active directory as the
identity management platform and as the core of their networks. AD DS contains
user accounts, computer accounts, security groups and policies which specify
authentication and authorization throughout the organization. There is a secure
deployment of AD and this ensures that only authorized users may access
resources, password policies, multi-factor authentication and account eligible
lockout measures are always enforced. As attention to Active Directory determines
permissions throughout the network, its security has a direct impact on the
security level of the entire domain.
DNS and Security Implication of DNS
Name resolution in the network is required by the Domain
Name System (DNS) role which is also a common target of attackers. Secure DNS
configuration is used to verify that traffic is routed appropriately and its
use will help in deterring attackers who may resort to spoofing or poisoning of
DNS records. Windows server DNS also has secured dynamic updates, DNSSEC and
conditional forwarding among others that assist in protecting the network
communication.
DHCP and Controlled Address
Management
The DHCP role is automated in assigning IP addresses, subnet
masks and gateways among other configuration information. An insecurely secured
DHCP server can be used to give the clients inaccurate network configuration so
that they will be redirected to rogue servers or denial-of-service situations
are achieved. DHCP snooping should be enabled on switches and authorized DHCP
servers placed in trusted subnets to ensure that rogue DHCP servers are not
operational. The DHCP in combination with Active Directory also makes sure that
the network configurations are only provided to the authenticated devices.
Network Policy Server (NPS) of Access
Control
Network Policy Server applies both authentication and
authorization policies to devices that seek to get access to the network. Being
the Windows version of the RADIUS, NPS aids in the protection of Wi-Fi
networks, VPN connectors, and wired ports through 802.1X authentication. NPS
centralizes access control of the network and only compliant and authorized
devices can be used on the network.
File and Storage Services
The file services role in Windows server provides security
to storage of data by the means of NTFS permissions, share-based permissions,
file screening and encryption. Access to sensitive files can be limited by
organizational roles but auditing options allow one to see the pattern of
access, as well as possible misuse. DFS also enhances availability of data and
prevents loss of data. The separation of the file servers in special subnets
with limited access assists in deterring the unauthenticated users’ access to
confidential information.
Conclusion
An important part of secure network architecture is subnetting and role of windows server. Subnetting enhances security as it separates devices, manages broadcast domains as well as enforcing access boundaries. The roles of windows server offer identity management, authentication, safe data storage and controlled access to the network.
