Dynamic Host Configuration Protocol (DHCP) is a protocol to dynamically giva an IP address to different devices. In cisco, defining DHCP is following these steps: Define DHCP exclude-address: We separate unwanted address in DHCP Define DHCP Pool : We define DHCP pool which is assigned to clients Define network, dns-server and default router SW1# conf […]
1-1 What’s port Security In Cisco switches, you can limit PCs based on their Mac-address. Port security enhances the security in Cisco devices Let’s implement a scenario to learn more about port security: Senario 1: In company A, we want to define port-security to learn mac-address of all PCs on the nework and maximum each […]
SSH, also known as Secure Socket Shell, is a network protocol that provides administrators with a secure way to access a remote computer. To have a secure connection to Cisco devices, we don’t use Telnet. Because Telnet sends the password in plain Text. If you use kind of sniffer tools such as Wireshark, you can […]
1-1 What is VTP? VTP is a layer 2 messaging protocol which is a Cisco proprietary protocol that propagates the definition of Virtual Local Area Networks (VLAN) on the whole local area network. VTP minimizes misconfigurations and configuration inconsistencies that can result in a number of problems, such as duplicate VLAN names, incorrect VLAN-type specifications, […]
In Cisco we have two types of access-list: Standard It’s based on source address It uses lower process utilization Extended It’s based on source/destination and port number It uses high process utilization We define access-list only on routers or layer3 switches. You can’t define access-list on layer 2 switches 1-1 Standard Acess-list Enter a caption […]
Router-On-a-stick Enter a caption for this image (optional) To connect several vlans together, there is a model which is called “Router-on-a-stick“. This model has some advantages: Cost effective Easy to Implement On the other hand, there are some drawbacks in this model: Congestion on link(bottleneck on trunk port) If router becomes down, network will down […]
1-1 What’s Trunk port? A trunk port is a port that is assigned to carry traffic for all the VLANs.Trunk send Untagged and Tagged information. There are two standards for Trunking: ISL(Cisco) 802.1Q(Industry Standard) is 4 Byte which is considered without Native Vlan Example: Trunk between two switches Enter a caption for this image (optional) […]
A virtual LAN (Local Area Network) is a logical subnetwork that can group together a collection of devices from different physical LAN. 1-1 Create VLAN Imagine that we have different departments on your company and you want to separate each department based on their employees. So, with the VLAN concept you can create a VLAN […]
Intro In this section learn how to set initial configuration in Cisco devices. You can also follow the video of this section on my channel on YouTube. We have 3 modes in Cisco devices, namely: Modes Symbols command User mode switch> – Privilege mode switch# enter enable in user mode Global mode switch(config)# enter config […]
The first question is asked by those who are using Cisco devices for the first time is that how can I connect to Cisco devices. It needs kind of cable which is called rollover cable. Rollover cable Enter a caption for this image (optional) rollover cable contains RJ-45 and RS-232 and as it is demonstrated […]
Introduction When running a website, there are often parts of the site that you’ll want to restrict from visitors. Web applications may provide their own authentication and authorization methods, but the web server itself can also be used to restrict access if these are inadequate or unavailable. In this guide, we’ll demonstrate how to password-protect […]