Instructor: In this lesson,
we will learn about network issues.
Network issues include problems
that disrupt the normal flow of network data
and affect connectivity, performance, or security.
Network issues include
network access control list, or NACL, issues,
resource exhaustion,
and DDoS, or distributed denial of service, attacks.
NACL issues arise when incorrectly configured rules
allow inappropriate network traffic
or block legitimate network traffic.
Resource exhaustion is the depletion of critical resources
like bandwidth, memory, or processing power.
And DDoS, or distributed denial of service, attacks
involve overwhelming a network or service
with a flood of traffic from multiple sources
with the goal of resource exhaustion
and making the targeted services
unavailable to legitimate users.
Let's learn more about
network access control list issues, resource exhaustion,
and distributed denial of service attacks.
First we have
network access control list, or NACL, issues.
A network access control list is a set of rules
that determines what kind of traffic
is allowed into and out of a network.
These rules can either permit or deny traffic
based on factors like source IP addresses,
destination IP addresses, and protocols.
If these rules are misconfigured,
they may accidentally block legitimate traffic,
which can lead to disruptions in business operations.
For example, a misconfigured NACL
might unintentionally block access
to a company's internal applications
by filtering out the IP address range
used by a remote employee's geographical location.
As a result,
the employee would be unable to access internal systems
such as the company's financial databases
or internal email servers,
preventing them from completing time-sensitive tasks
and negatively impacting overall productivity.
This type of issue usually goes unnoticed
until it begins to affect multiple users
or critical systems.
Aside from blocking legitimate traffic,
NACL issues can also result in security vulnerabilities.
If a network access control list is too permissive,
it may allow harmful traffic into the network,
increasing the risk of attack.
For instance, if rules are not properly set
to deny unnecessary incoming traffic
from untrusted or known bad IP addresses,
attackers could exploit open ports
to infiltrate the network.
In these cases,
NACLs that fail to properly restrict network traffic
can leave sensitive data and systems exposed to threats
like malware and unauthorized access.
So, to avoid network access control list issues,
regular auditing and fine tuning of the rules are necessary.
Network administrators should carefully design NACLs
to balance security and accessibility,
ensuring that legitimate traffic flows smoothly
while malicious or unnecessary traffic is blocked.
Automated tools such as network monitoring systems
like SolarWinds, Cisco Prime, or AWS CloudWatch
can also help by monitoring network traffic
and identifying potential configuration errors
before they lead to serious disruptions
or security breaches.
Second, we have resource exhaustion.
Resource exhaustion occurs
when a network's critical resources
like bandwidth, memory, or processing power are depleted,
leading to performance issues or outages.
In an enterprise network,
resource exhaustion often results
from excessive demand placed on servers or network devices.
For example, a sudden surge in user activity
during peak business hours
can consume all available bandwidth,
causing slowdowns or making services
temporarily unavailable.
If not managed properly,
resource exhaustion can degrade productivity
and customer experience.
Along with excessive demand,
another cause of resource exhaustion
is inefficient resource management.
Poorly optimized applications, outdated hardware,
or unbalanced workloads
can put excessive strain on network resources,
leading to reduced performance and even system failures.
For example, if a critical server
is not properly load balanced,
it may receive far more traffic than it can handle.
This could cause the server to slow down,
experience a high latency, or even crash,
resulting in downtime for essential services
like email, databases, or customer-facing applications.
Such an outage not only disrupt normal business operations
but can also affect user experience
and potentially lead to revenue loss.
So, mitigating resource exhaustion
involves proactive monitoring and scaling resources
based on demand.
This can include
dynamically adding more bandwidth, upgrading hardware,
or optimizing applications to handle larger loads.
Network administrators can also use load balancers
and traffic prioritization
to ensure critical services remain operational
even during periods of high demand.
Third and last,
we have distributed denial of service, or DDoS, attacks.
Distributed denial of service attacks
are one of the most common forms of resource exhaustion
in enterprise networks.
In a DDoS attack,
attackers flood a target with traffic from multiple sources,
overwhelming the network's capacity
and making it impossible for legitimate users
to access services.
For example, in a large-scale DDoS attack
on an e-commerce company's website,
millions of fake requests might be generated
from thousands of compromised devices worldwide.
These requests would overwhelm the website's server,
causing slow performance
or making the site completely unreachable
to actual customers trying to make purchases,
resulting in significant financial loss.
DDoS attacks can have serious consequences
for enterprise networks,
including loss of revenue,
damage to reputation and downtime.
Attackers often target vulnerable networks
that lack proper defenses,
such as improperly configured network access control lists
or outdated firewalls.
The flood of traffic can also overwhelm network devices
like routers and switches,
leading to a complete network failure.
So, preventing DDoS attacks
involves using specialized tools
such as DDoS mitigation services
that can detect and filter out malicious traffic.
Firewalls, intrusion detection systems,
and properly configured network access control lists
can also help block suspicious traffic
before it reaches critical systems.
Additionally, distributing network resources
across multiple data centers
can reduce the risk of a single point of failure
during a large-scale DDoS attack.
By implementing these measures,
enterprises can reduce the likelihood
of a successful DDoS attack
and maintain network availability
during malicious traffic surges.
So, remember, network issues can significantly disrupt
the flow of data,
affecting connectivity, performance, and security
in enterprise networks.
Common network issues include
network access control list problems, resource exhaustion,
and distributed denial of service attacks.
Network access control list issues
occur when misconfigured rules
either block legitimate traffic
or allow harmful traffic to enter the network.
Next, resource exhaustion happens when critical resources
like bandwidth, memory, or processing power are depleted,
causing degraded performance or outages.
Finally, distributed denial of service attacks
overwhelm networks with a flood of traffic
from multiple sources,
leading to resource exhaustion
and making services unavailable to legitimate users.