CompTia Network + Troubleshooting Network Services

Network Services

Essential components that manage various operations within a computer network

Mac Address

Used to uniquely identify a network interface card on a given network

Logical Domain Manager

Listens to multicast messages on a network and keeps track of the MAC addresses being used

Duplicate IP Address/ IP Address Conflict

Occurs when another computer on the same network has an identical IP to another workstation or server on the same network

Dynamic Host Configuration Protocol (DHCP)

Network management protocol uses on Ip networks to automatically assign Ip addresses and other communication parameters to devices connected to the network using a client-server architecture

Rogue DHCP Server

A DHCP server on a network which is not under the administrative control of the network administrators

DHCP Scope Exhaustion

Occurs when the DHCP server runs out of valid IPs to assign to the clients requesting access on the network

Multicast Flooding

No specific host is associated with the multicast MAC address in the CAM table of the switch

Asymmetrical Routing

Network packets leave via one path and return via a different path

Missing Routes

When a router cannot reach a destination because there is a missing route in the routing table

Switching Loop

Occurs whenever there is more than one path between the source and destination devices

Routing Loop

Formed when an error occurs in the operation of the routing algorithm and creates a circular route amongst a group of network devices

Split Horizon

Routing configuration that stops a route form being advertised back in the direction from which it came

Route Poisoning

Increasing a router’s metric to an infinitely high number after detecting one of its connected routes has failed

Hold-down Timer

Prevents bad routes from being restored and passed to another routers by accident

Firewall

Network security device that monitors and filters incoming and outgoing network traffic based upon established rule sets

Host-based Firewall

Runs on an individual computer or device connected to the network to protect that one device

Network-based Firewall

Deployed in line with the network traffic flow to monitor and filter incoming and outgoing network traffic based on established rule sets

Access Control List (ACL)

Provides security by blocking unauthorized users and allowing authorized users to access specific resources

DNS

Mathces domain names with the corresponding IP addresses used by a server

DNS Latency

Time and delay that occurs whenever users request a particular domain name

NTP

Allows synchronization of system clocks between different layers of a hierarchical, semi-layered system of time sources