Prefix-Lists Hacking.

ip prefix-list A permit ge 32 The above statement will match only hosts. ip prefix-list B permit ge 17 The above statement will match Any subnet in a class B address space. ip prefix-list C permit le 32 The above statement will match all routes. ip prefix-list D permit The above statement will match… Read More »

How To Check System Uptime in Linux Server.

if you want to check the uptime of your Linux server then there are a few commands which you can use effectively for collecting this information on system uptime. The first command which I prefer to use is uptime. Let’s look at the output given below. The second command is Top command. The third one is W Command.

GPON Splitter Loss Chart

Splitters are used for dividing one or two optical signals into multiple optical signals.splitters are passive optical devices that are widely used in Passive Optical Networkssuch as GPON, and EPON. There are different types of splitters we have and every splitter has a different insertion loss, So this is very important to understand in the FTTx network when… Read More »


SSL and TLS are used for securing and encrypting the connection between the mail client and the mail server. When I am talking about securing it means to secure the communication between the websites and browser where the user actually interacts with the application for accessing the server resources. By default without SSL & TLS, The communication happens… Read More »

Day-34: Voice VLAN.

A voice VLAN is a VLAN ( virtual local area network) that is specifically allocated for the user’s voice data as we all know the VoIP traffic is very sensitive and VOIP traffic can deal with the delay, Bandwidth congestion, etc. The reason we need Voice VLAN is to prioritize that traffic after separating them. Once you will… Read More »

Day-33: Port Security.

Port security to filter traffic that is destined to or received from a specific host that is based on the host MAC address. Port Security feature remembers the Ethernet MAC address connected to the switch port and allows only that MAC address to communicate on that port. If any other MAC address tries to communicate through the port,… Read More »

Day-32: DTP(Dynamic Trunking Protocol).

DTP is a Cisco proprietary protocol that is automatically enabled on Catalyst 2960 and Catalyst 3560 Series switches. Switches from other vendors do not support DTP. DTP manages trunk negotiation only if the port on the neighbor switch is configured in a trunk mode that supports DTP. There are 2 dynamic modes available for the switchport mode command:… Read More »

Day-31: Native Vlans.

The major difference between a regular VLAN and the native VLAN is that frames from/to the native VLAN are carried untagged. The native VLAN is the one into which untagged traffic will be put when it’s received on a trunk port. This makes it possible for your VLAN to support legacy devices or devices that don’t tag their… Read More »

Day-30: ISL & 802.1Q Encapsulation.

ISL is a Cisco proprietary protocol and it Supports up to 1000 VLANs. ISL adds a 26-byte header and a 4-byte FCS (frame check sequence) is inserted. Hence a total of 30 Bytes of overhead so ISL is less preferred in networks because of its high overhead value which is added to each Ethernet frame. In ISL, the… Read More »