Category: <span>Networking</span>

Transmission Control Protocol (TCP) – is a connection-oriented communications protocol that is used to ensure reliable transmission of packets between computing devices in a network. User Datagram Protocol (UDP) – is a connection-less communications protocol that is used especially for time-sensitive and low latency transmissions across the network. Here’s a table of comparison: Parameter TCP UDP Protocol connection-oriented connection-less Header Size 20 bytes Static header 8 bytes Checksum Compulsory Optional Overhead Heavy as it needs 3 packets to setup a…

Networking

Some Useful 10GBASE Small Form-Factor Pluggable (SFP) Transceiver Modules Model Distance Wavelength  Mode Medium Interface  Temp. SFP-10G-SR 300m 850nm Multimode Fiber Duplex LC 0-70℃ SFP-10G-LR 10km 1310nm Singlemode Fiber Duplex LC 0-70℃ SFP-10G-LRM 220m 1310nm Multimode Fiber Duplex LC 0-70℃ SFP-10G-ER 40km 1550nm Snglemode Fiber Duplex LC 0-70℃ SFP-10G-ZR 80km 1550nm Singlemode Fiber Duplex LC 0-70℃ Parameter 10GBASE-LR 10GBASE-ER 10GBASE-ZR Transmit Power (max) −1.0 dBm 2.0 dBm 4.0 dBm Transmit Power (min) −6.0 dBm −1.0 dBm 0.0 dBm Receive power…

Networking

Here’s a comparison table between the two network models: Open Systems Interconnect (OSI) vs Transmission Control Protocol/Internet Protocol (TCP/IP) Similarities: both are defined in layered architecture both define standards for networking both are logical models both provide framework for creation and implementation of  networking standards and devices both models simplify network troubleshooting process Differences: OSI is protocol independent standard while TCP/IP model is based on standard protocols which Internet has developed OSI model is developed by International Standard Organization (ISO)…

Networking

  Here’s you can choose to remember the 7 Layers of Open Systems Interconnection (OSI) From Application to Physical: (A)pplication (A)ll (P)resentation (P)eople (S)ession (S)eem (T)ransport (T)o (N)etwork (N)eed (D)ata Link (D)ata (P)hysical (P)rocessing Some other Mnemonics are: A Penguin Said That Nobody Drinks PepsiA Priest Saw Two Nuns Doing PushupsAll Pros Search Top Notch Donut Places From Physical to Application: (P)hysical (P)lease (D)ata Link (D)o (N)etwork (N)ot (T)ransport (T)hrow (S)ession (S)ausage (P)resentation (P)izza (A)pplication (A)way Some other Mnemonics are:…

Networking

OSI or Open Systems Interconnection model consists of 7 Layers that describes how telecommunication or computing systems use to communicate or operate over a network. It was the first standard model for network communications and still widely used for network isolation and troubleshooting. Layers Functions / Applications Data Types Examples (7) Application End User / Desktop-Mail Services-Directory Services-Network Virtual Terminal-File transfer access/management Data HTTP,SMTP,FTP,SSH,DNS,Telnet,IMAP,POP3,LDAP,HTTPs,TFTP (6) Presentation Syntax/ Data Representation-Translation-Encryption/Decryption (plain to cipher text)-Compression Data ASCII,JPEG,MPEG,GIF,EBDIC (5) Session Dialog Coordination-Session establishment/maintenance/termination-Synchronization-Dialog…

Networking

We are going to configure VRRP between the 2 pairs of routers and the expected behavior, setup as per below: Setup: 1. Routers PE1,PE2,FW1 and FW2 are connected to the same Layer 2 Switch and belongs to the same VLAN. 2. L2-Switch will just function as Layer 2 switch (subnet 192.168.2.240/29) 3. VRRP is configured between PE1 & PE2 3. VRRP is configured between FW1 & FW2   Fig.1 IP & VRRP Configuration: L2-SWITCH L2-SWITCH#conf t a. Setup access VLAN…

Cisco Networking

Fiber Optic Transceivers are wavelength-specific lasers that can convert electrical data signals into optical signals via optical fiber. It is basically a device that uses fiber optical technology in sending and receiving data. Here’s the classifications:   Based on form factors 1. XENPAK – original 10G pluggable optics using SC connector type 2. X2 -provides 10G connectivity up to 40km on SMF and successor of XENPAK. Also used SC connectors 3. GBIC -short for Gigabit Interface Converter, is a standard…

Datacenter Networking

Autonomous System or AS is a set of routable IP prefixes that belongs to a network or collections of networks managed by a single entity such as ISP, corporate network, university, etc. and maintain a single or common routing policy. Each AS has to be represented by unique number called Autonomous System Number or ASN to control and exchange routing information with others. Two formats of ASNs: 2-byte ASN (16-bit number) –> provides for 65,536 ASNS (0 to 65535) .…

Networking

UTP or Unshielded Twisted Pair is a type of copper cabling used in LANs and has several categories based on the TIA/EIA 568 standard namely as CAT3,CAT4,CAT5,CAT5E and CAT6. Common connector used with these UTP cables are RJ-45. Most common used now are CAT5e as it supports up to 1Gbps for 100 meters, and now CAT6 is becoming popular to LAN and datacenter networks as it supports 1Gbps for 100 meters and up to 10Gbps for 50 meters. As of…

Networking

In routing world, Administrative Distance refers to the reliability of the routing protocol. It is equivalent to Juniper’s Route Preference and Huawei’s Preference. It is important to consider these values as in the scenario that there are multiple routes to a destination (with same prefix length), the route (learned via the routing protocol) with the lowest value is preferred. Table below will show the values for respective platform.   Routing Protocol Cisco(AD) Juniper (RP) Huawei(P) Connected Interface 0 0 0…

Networking