Routing is a huge concept in Cisco and I don’t want to dive into routing protcols concept, but I want to focus on simple routing which is called Static Routing. To know this concept look at this diagram. In static routnig, to reach from network1 to network2 , you need to define networks in router1 […]
Network address translation (NAT) is a method of remapping one IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic routing device(wiki). In simple word, translating IP address to another IP is called NAT. Imagine that, we have one static IP […]
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 […]