24) Common Network Issues

Practice flashcards covering switching issues, STP states and roles, routing table problems, and IP addressing configuration issues based on the CompTIA Network+ N10-009 course notes.

Spanning Tree Protocol (STP)

A network protocol critical for preventing network loops and ensuring efficient data flow by creating a loop-free logical topology.

Network Loops

Occur when multiple active paths exist between network switches, causing broadcast storms and network congestion.

Root Bridge

The central reference point in an STP-enabled network, determined by the lowest bridge ID.

Bridge ID

A value used in root bridge selection that consists of a priority value and the MAC address.

Root Port

The STP assigned port role that represents the best path to the root bridge.

Designated Port

The STP assigned port role that represents the best path to a specific network segment.

Blocked Port

The STP assigned port role that prevents loops by not forwarding traffic.

Blocking State

An STP port state that prevents traffic flow to avoid network loops.

Listening State

An STP port state where the port prepares to forward traffic without adding to the MAC table.

Learning State

An STP port state that adds MAC addresses to the table without forwarding traffic.

Forwarding State

An STP port state that actively forwards network traffic.

Incorrect VLAN Assignment

A configuration issue leading to network segmentation problems or unauthorized access to restricted segments.

Access Control Lists (ACLs)

Tools used to control network traffic by specifying which users or systems can access network resources and under what conditions.

Stale Routes

Routes in a routing table that are no longer valid but remain, potentially causing the misrouting of packets.

Misconfigured Static Routes

Incorrect manual route entries that can lead to packet loss and routing loops.

Dynamic Routing Protocol Conflicts

Inconsistent routing information caused by misconfigured protocols such as OSPF, EIGRP, and BGP.

Missing Default Route

The absence of a route to handle traffic for unspecified destinations, which causes packets for unknown networks to be dropped.

Address Pool Exhaustion

Occurs when available IP addresses in a network’s DHCP scope or subnet are depleted.

Over-subscription

A condition where too many devices attempt to obtain IP addresses from a limited DHCP pool.

IP Address Management (IPAM)

Implementation used to monitor and optimize IP address allocation to resolve pool exhaustion issues.

Incorrect Default Gateway

A configuration error preventing devices from communicating with other networks, often due to the gateway IP being outside the subnet or misconfigured.

Static vs. DHCP Conflicts

A connectivity issue occurring when manually assigned static IP addresses conflict with dynamically assigned DHCP addresses.

Duplicate IP Address

Occurs when two devices on the same network are assigned the same IP address, causing network conflicts.

Incorrect Subnet Mask

A configuration error that leads to improper network segmentation, causing devices to fail in communicating with each other.