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)…
Category: <span>Networking</span>
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:…
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…
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…
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…
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) .…
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…
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…
“Bogon” or coined from the word “bogus”, In computer world, these are IP addresses that have not been officially assigned to an entity such as IANA or Internet Assigned Number Authority which is an organization who managed allocation of globally unique IPs. Bogon IP adddress/ranges should not appear on the public Internet so network engineers should filter these as they are meant for use only in private networks and considered reserved for special purposes. You can refer to Team Cymru website…
This is very useful for IP address planning and management especially for network engineers as part of designing their network. This is one of the consideration in proper assignment of IPs to the network devices and hosts. IPv4 Address Classes Classes IP Address Range A 0.0.0.0 – 127.255.255.255 B 128.0.0.0 – 191.255.255.255 C 192.0.0.0 – 223.255.255.255 D 224.0.0.0 – 239.255.255.255 E 240.0.0.0 – 255.255.255.255 Reserved (Private) IPv4 Classes IP Address Range A 10.0.0.0 – 10.255.255.255 B 172.16.0.0 – 172.31.255.255…
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