Author: Joshua

Wireless WiFi Roaming

wireless wifi roaming

Understanding wireless & WiFi Roaming is very important in WLAN and WiFi computer networking. It occurs when a wireless client moves around in a region with many access points (APs). It may switch automatically to another access point (AP) with more preferred signal strength.   Understanding Wireless Roaming Types The wireless roaming types are: Intra-Controller roaming, Roaming between controllers (L2 Roaming and L3 Roaming), and Roaming between Autonomous APs   Understanding Wireless & WiFi Roaming between Centralized Controllers Also referred to as Inter-controller roaming. In this case, as the wireless network expands there are chances that the client needs to Read More …

Signals and Modulation of WiFi / Wireless

wireless-wifi-signals-modulation

Signals and Modulation of WiFi & Wireless are very important networking concepts for computer networking & are used in wireless communication. Wireless signals are crucial since they can transmit data in form of audio, video, etc without cables or wires. Modulation is the process of converting information signals into a different form. Some of the common types of wireless signals include Television and Radio Broadcasting, satellite, Global Positioning Systems (GPS), Bluetooth, Cellular phones, Wi-Fi, cellular phones, etc.   Wireless Signal terms Some of the important wireless terms are listed below: Frequency is defined as the number of cycles completed per Read More …

Network Assurance & Troubleshooting approaches

network assurance and troubleshooting

Network Assurance & troubleshooting is the act of finding network issues through a testable process and using provable methods to solve them. Network troubleshooting and assurance are implemented when there is a network failure or something bad happens to the network, to help diagnose and solve the issue. Network troubleshooting and assurance are implemented by network engineers to resolve network issues and improve operations   General Network Assurance & Troubleshooting Approach A structured network troubleshooting method is simply a guideline throughout the troubleshooting process. There are many approaches that we can choose from. The key to all structured troubleshooting methods Read More …

Network Troubleshooting Utilities and Tools

How to do network troubleshooting

Network Troubleshooting utilities and tools are used by network engineers to diagnose and resolve network issues or problems. The common type of network troubleshooting utilities and tools is the command-line tools and they include: ping, traceroute, debug, etc.   1. Ping (Network troubleshooting utilities) Ping as one of the network troubleshooting utilities and tools is one of the most valuable and well-known troubleshooting tools in networking. It uses a protocol known as ICMP (Internet Control Message Protocol). Ping uses two ICMP message types: Type8/Code0 (Echo Request) and Type0/Code0 (Echo Reply). When you issue a ping command, the source sends an Read More …

SNMP (Simple Network Management Protocol)

snmp

What is SNMP? SNMP (Simple Network Management Protocol) is a Layer-7 protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior. It allows devices to communicate even if the devices are different hardware and run different software. There are two major types of devices in SNMP, they are Managed devices which are devices being managed using SNMP and Network Management Station (NMS) which could be a device or devices managing the managed devices. It could also be seen as the SNMP server.   Features of SNMP (Simple Network Management Read More …

Syslog (System logging)

syslog server

What is Syslog? Syslog (System logging) is a Layer4 protocol for producing and sending log/event information from Cisco, Unix/Linux, and Windows Devices systems to a centralized log/event message collector called Syslog Server.   Features of Syslog Below are some important features of Syslog: The purpose of Syslog is for logs/errors management Syslog belongs to Layer4 of OSI Model Syslog servers listen on UDP port 514 for messages Syslog is a client push model     Syslog Logging Locations The following are the different locations Syslog messages can be sent to: Console line: This means that Syslog messages will be displayed Read More …

SPAN (Switch Port Analyzer)

span SWITCH PORT ANALYZER

What is SPAN? SPAN (Switch Port Analyzer) is a network protocol that collects and forwards switch traffic to the SPAN port for analysis. SPAN is also referred to as Port Mirroring or Port Monitoring. It can be enabled on both physical ports and VLANs.   Attributes of SPAN (Switch Port Analyzer) The attributes of the Switch Port Analyzer are: All ports related to a given session (whether source or destination) must belong to the same VLAN. If you don’t specify any interface in the port monitor command then all other ports belonging to the same VLAN as the interface will Read More …

Cisco NetFlow

cisco-netflow

NetFlow is a network protocol designed by Cisco which is used for collecting IP traffic information and monitoring network flow. By analyzing NetFlow data, you can get a picture of network flow and volume. Traffic can be grouped and analyzed based on different criteria like interface, source IP, destination IP, IP protocol, source/destination TCP/UDP port and service type. Routers and switches that support NetFlow can collect IP traffic statistics as NetFlow records towards at least one NetFlow collector server that does the actual traffic analysis.   Popular NetFlow Analyzer Software Popular NetFlow Analyzer Software Solutions are: SolarWinds NTA (NetFlow Traffic Read More …

OSPF (Open Shortest Path First)

ospf-routing-protocol

What is OSPF? OSPF (Open Shortest Path First) is an open source dynamic routing protocol based on Link State Routing Algorithm for IP Networks. It has a Protocol Type/Class which is based on IP/Link-State. OSPF uses an Algorithm called SPF (Dijkstra) to determine the shortest path. It is an IGP (Interior Gateway Protocol) Type of protocol and it uses Cost (Bandwidth) as its metric value. OSPF has 5 no. of packet types and has an Admin Distance of 110. It has a Reference Bandwidth of 108 and has a defined Standard of IETF RFC2328 (OSPFv2), IETF RFC2740 (OSPFv3/IPv6) for OSPF Read More …

Static and Default Routing

static-default-routing

Static and Default Routing are two types of routing in which the path selection is controlled manually by a network administrator. STATIC ROUTING “It is a type of fixed routing in which path selection and routing is controlled manually by a network admin”. Static routes have Admin Distance (AD) of 1. Path selection  and routing is manually controlled by a network administrator in static routing. Static routes are always preferred over Dynamic routing protocols like OSPF/RIP/BGP. They consume less resources and less bandwidth intensive. Static Routes are not fault tolerant (paths are always fixed). Therefore, they are not practical for Read More …