Security Issues in Software Defined Networks (pdf)

Security Issues in Software Defined Networks
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Table of Contents
Introduction..........................................................................................................................2
Issues which are associated and affects SDN......................................................................5
Quality of Service (QoS).....................................................................................................6
Solutions to security threats of SDN...................................................................................7
Conclusion...........................................................................................................................9
References..........................................................................................................................10

Introduction
Virtualization technology in early times was based on computational and storage of
resources. Hence most of the researchers were focused on computing and storage of resources.
Networking and data virtualization was not the main subject of the research (Wen, Tiwary, & Le,
2013). Today, systems infrastructure are emerging as key concept in cloud computing. Storages,
computing resource and networking are now being defined by software. The software defining
these resources are monitored and controlled centrally. In general, SDN will not be limited to
applications, platforms or even infrastructures of the systems, they will instead categorize their
needs and hence precisely outline their virtual environment on which they would operates on. An
in-depth on how SDN is implemented is that the system is incorporated in underutilized servers
that information technology organizations already operate and own (Wen, Tiwary, & Le, 2013).
In summary, the firmware of routers and network switches that has for a long time remained
under the control of the companies that manufacture this equipment is been changed by making
this remotely modifiable and remotely accessible through third-party software clients, making
use of open flow an example an open protocol (IEEE Staff, 2016). SDN allows for external
access to the innards of routers and switches that were formally proprietary and closed and also
for quick optimization and experimenting of routing or switching policies.
The switching fabric of conventional Layer 2/3 networks serves as routing and switching
material for the blade center server chassis. These switches have the capability of layer two
switching and layer three routing providing security and flexible traffic management in the frame
(Abro, 2015). The layer 2/3 fiber GbE and Copper switching modules offers full layer two
switching making capabilities available such as link aggregation control, Cisco Ether channel,
advanced spanning tree protocols and 802.1Q VLANs, Internet Group Management Protocol

(IGMP), performance features and application delivery such as granular QoS, multicasting and
snooping.
The open flow technology showcases network programmability through the remote
control application which is all about remotely and directly programming a network switch to
handle traffic dynamically in a particular way making use of the CLI type of commands (Zhang
& Chen, 2016). An example, to achieve the forward flow to a specific switch port, ensure other
streams are blocked, while the switch is programmed to make such actions alternate in a
predefined manner, i.e. time interval of say 40 seconds. Use this demonstration using some
servers that are to listen to the same multicast address while the switch is being programmed to
allow a single server to give airplay to an individual client in the case of video servers. This
application is applicable in the context of software-defined networking as it empowers the
operator, user, and administrator to have an own definition of treating traffic (Artmann &
Khondoker, 2018). This, in a way, resembles the activities and operations of a TV remote
control where one can switch through channels only that in this case, it is automatic. This is
transparent to the end host in that clients and video servers are unaware of the switch managing
or controlling the traffic.
A command-line interface (CLI) is a dialog or an interface where two programs or the
user and the program pass a command line in SDN it is an essential critical aspect. Such
command lines used in software-defined networks are some of the windows shell and OS/2
presentation manager these graphical interfaces help programs and users communicate with their
execution strategies such as opening applications and documents. The registry or the graphical
shell is where these commands are stored (Azodolmolky, 2013). In SDN standard input/output
interface (stdin $ stdout) can be employed to look for console hacks allowed to store and edit

commands in software. In network management, a configuration is regarded as one of the most
vital functions. Especially, with a new device added to the existing network, an appropriate
setting necessary to accomplish a consistent network operation.
Securing the SDN is a critical area that should be taken care of since it offers a global
view and also programmability to control (Zhang & Chen, 2016). Thus, three future risks may be
encountered in SDN. First, the controller is one of the most critical components in the SDN
architecture as it defines the overall data flow that occurs in the traffic flow manager (data
plane). If it is compromised, the attacker may disrupt the data path of the network. Thus, to cope
with such a threat, the Current Research on Security initiated a significant amount of
virtualization scenario on the SDN layers to ensure that the attackers are unable to figure out the
actual physical network. It will provide a prominent security mechanism for the SDN (Bombal,
2017).
Secondly, the OpenFlow may present limitations regarding security contexts. Even
though the SDN control languages and protocols, such as Frenetic and Procera, have been
designed, the OpenFlow gains the dominant position in the network. In fact, the OpenFlow
evolves, enhancing the processing of more protocol headers. In this process, it exhibits some
drawbacks since it is associated with stringent definition fields used by the forwarding rules, and
they may be altered (Tantayakul, Dhaou, & Paillassa, 2017). For instance, the area used in IPv6
protocol was introduced when OpenFlow version 1.3 emerged. Thus, there is a possibility of
changing the protocol field in the OpenFlow and switching in the network becomes more
complicated.
Lastly, lack of middle-boxes in SDN may cause a future security problem. The current
operating network is implemented in the form of additional devices called middleboxes, such as

firewalls, routers, NAT devices or switches. Therefore, when a system lacks such tools, it
implies that there is a deficiency in security (Castaldi & Tobia, 2015). It facilitates end-to-end
connectivity that is required for some network applications in the existing network. As a result, a
legacy problem on applying and tuning the traffic rules or the encrypted data streams.
Issues which are associated and affects SDN.
Security is a problematic issue that affects SDN networks. The ability to
protect the controller which controls other data planes is a significant
challenge that needs to be looked at. Another problem is service denial
attacks which reside in networks that are defined by software. Intrusions
inversions are also common in systems defined networks. A net fuse
mechanism was proposed by researchers to protect data that is stored in the
cloud from an overload of traffic. The net fuse was placed between the
controller and switches in the networks of SDN (Comer, 2015). In recent
times, data centers have been significantly affected by the wrong
configurations, cyber-attacks workload changes in a network. Open flow
regulated messages are indirectly collected to identify and detects streams
in a network. To control the rate of traffic in a network, network overloading
changes are looked at to determine multidimensional flows in a system.
Various mechanisms are applied to control and monitor traffic which poses a
threat in. The controlling component is implemented with passive and active
listening mechanisms to check the network information (Cooklev, 2015). It
interferes with control of messages on the network. The logic controller
receives back information that has failed to match with the assigned switch

after it gets, the feedback is sent to the switch using forwarding rules that
outline flow method of the message or information.
Quality of Service (QoS)
The ability to provide services is known as quality of service Quality of
Service. It is difficult to attain the desired excellent quality of service in SDN
networks. The SDN systems at sometimes fail to offer the users of good and
quality services; this is because the users are limited to resources that are
stored in data centers (Stallings, Jelassi, & Agboma, 2015). The center
controlled system in case of a break down lead to denial of services to all
users of the system. The primary quality of service is essential to achieve
and guaranteed bandwidth, reduce the loss of data, reduce congestion and
minimize the delay time when service is requested from the database. In the
review, the research work was represented to solve the challenges that
come with the quality of service in SDN. The report proposed a protocol
which was based on the controller to achieve the end to end excellent and
affordable services for applications based on media (Doherty, 2016).
Quality of services provided by SDN was measured through the failures
of redundant links. Complicated algorithms were introduced to address
optimization of assets. Load balancing formulae were added to control traffic
on networks. The mechanisms developed was to support one big class that
entails, infrastructure virtualization and network mechanism security which
would help to curb or control attacks on the networks. Quality and robust

policies were introduced to minimize incidents of network attacks (Duan &
Toy, 2017). Software technology and continuous hardware evaluation were
leveraged thirty years ago with feature switching of the art. To achieve good
network implementations, the survey found that, automation and
virtualization requires a rapid change from closed, extensible, vendor
specific, proper system for networking and external operating should be
easily be upgraded or programmed. This requirement is open and extensible
and is monitored and guided by laid down policies that regulate and control
resources in data centers should be dynamically managed as one system
which has many integrated components made up of the network,
computational data and storage devices (Robertazzi, 2017). Networks that
are software-defined are coming up a new technique, those clear ways for
network shared resources and virtualization that are increasing demand. The
SDN technique hides the functional operations of the system, by providing an
obstruction to applications that reside in the upper layer of the system to the
underlying network system. Generally, the devices that are used for
networking such as routers, switches have their data plane, Management
plane, and control plane while the networks software definitions apply
control logic and data planes which are separately decoupled (Galán-
Jiménez, 2018). The logic control plane is employed as a component of
software where it is kept in the server of the networking system. The data
centers are found or held in the devices that connect to the internet.

Solutions to security threats of SDN.
Security is a significant concern when it comes to software-defined
networks. A lot of efforts should be taken to ensure data center in the cloud
is secured. Security means that hardware, network and applications systems
using SDN networks are secured. Therefore hardware such computers should
be well kept and secured. The servers where the controller of SDN system
should have highly trained experts to monitor and control it, this will
minimize cyber-attacks which may lead to system failure either due to
service denial (Goransson, Black, & Culver, 2017). Proper policies that govern
SDN networks should be employed to ensure quality and standard of
networks that are recognized globally. Frequent checks of network should
frequently be done to assist in identifying loopholes that may be used by
hackers to penetrate the servers where data resides. In conclusion, security
is a significant threat to SDN network. Hence more effort on research should
be carried out to curb this arising issue.
The review has shown that SDN, is effectively managing and
virtualizing environment to meet the demands of network resources. They
are now focusing on how to attain scalability, minimum load balance,
security and excellent quality of services in a network (Qi & Li, 2016). The
main idea behind this review is to establish and recognize the efforts applied
to address challenges that were and still facing networks that which are
defined by networks. Cloud computing is grouped into 3, one of the group is
infrastructure as a service that is implemented through virtualization of the

environment. The second category is “platform as a service” and third is
where the platform is regarded as a service (Kadiyala & Cobb, 2017). The
virtualization of technology has acted as the primary method of service
delivery, through the provision of resources stored in the cloud. However, in
recent years, many of researchers have focused on computing and storage
resources of SDN using a technique of technology virtualization such as
kernel virtual machine and other applications such as XEN APP which is used
in cloud computing (Nadeau & Gray, 2013). The main thing that is pushing
researchers to expand their knowledge on traditional networks is
environment virtualization and cloud computing which rapidly increasing and
easily incorporated to the enterprises. The operators are not fixed to
automation of network and data centers which are connected by LAN and
WLAN.
The decoupling of logic data and control has changed the networking
resources to be automated, controlled and programmed to meets
increasingly needs by business corporates and enterprises. In addition to
that, networks which are defined by software, are replacing the networking
device functionalities to forwarding network devices (Marschke, Doyle, &
Moyer, 2015). The ability to decide how and where to make a forwarding is
outlined and explained on the control plane. In a software called controller is
where the logic control of the network is implemented. Protocol or procedure
of open flow is used to link the networking devices with the controller to
enhance effective communication between them. Some of most known

network system controllers in the market are a beacon, floodlight, and Nixes.
The networking controller, after receiving the packets of data, it sends them
to the switches that are based on open flow to control and maintain flaws of
data in the switches. The controller then tries to match the flow entry of data
and decide to send the packet of data to the right port; it may also choose to
discard the packet of data. In a situation where the data received is not
matching the available data, encapsulations are done, and data packets are
sent back to where they came from, i.e. controller receives back data packet
(Nadeau & Gray, 2013).
Conclusion
In conclusion, the controller of networks has the mandate to decide
packet data; it can signal a switch to drop a particular packet of data or
create new entries into the flow of data in support of packet flow. Even
though the software-defined networks has overwhelming advantages over
the conventional, traditional networks, it has sprouted out its negative
affecting issues. In a survey, four problems challenging of SDN were
identified such as load balancing, quality of the service, scalability, and
security. Ongoing efforts have been presented and summarized to curb or
control the challenging issues that are facing software-defined networks. In
conclusion, the survey found out techniques that would be used to address
problems facing or challenging network established networks; the issues are
looked at on the last page of this assessment. SDN provides better performance,
higher flexibility as well as an efficient configuration that accommodate innovative network

designs. The openness of SDN also encourages network operators to write control programs.
However, future risks such as malicious attacks, lack of middleboxes causing problems on
applying and tuning the traffic rules, and complications of the dominant OpenFlow in SDN.
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