Network Port Aggregation PDF

LECTURE NOTES 6: PORT AGGREGATION (LINK AGGREGATION) 1. Introduction to Port Aggregation (Link Aggregation) ✓ Port Aggregation, also known as Link Aggregation or EtherChannel, is a network technology used to combine multiple physical network links into one logical link. This process incre...

LECTURE NOTES 6: PORT AGGREGATION (LINK AGGREGATION) 1. Introduction to Port Aggregation (Link Aggregation) ✓ Port Aggregation, also known as Link Aggregation or EtherChannel, is a network technology used to combine multiple physical network links into one logical link. This process increases the bandwidth available between switches or between a switch and a server while providing redundancy to protect against individual link failures. Key Concepts: ✓ EtherChannel: A term often used interchangeably with Link Aggregation in Cisco devices. It refers to the bundled logical connection. ✓ Logical Link: Although multiple physical links are used, the network treats them as one logical connection, simplifying management and balancing traffic across links. ✓ Redundancy: If one link in the aggregated group fails, the others continue to carry traffic, ensuring uninterrupted network operation. 2. Benefits of Link Aggregation Increased Bandwidth: ✓ By aggregating several physical links into one, Link Aggregation provides increased total bandwidth between devices. ✓ For example, aggregating two 1 Gbps links results in a 2 Gbps logical connection, providing more capacity for network traffic. Load Balancing: ✓ Link Aggregation distributes traffic across the bundled links based on algorithms like source/destination IP address or MAC address, balancing the load and preventing any single link from becoming overloaded. Redundancy and Failover: ✓ If one link in the aggregation group fails, the remaining links automatically take over the traffic without interrupting service. This improves network reliability. Simplified Management: ✓ Multiple physical links are managed as a single entity (logical link), reducing administrative overhead. The network administrator configures one logical interface rather than managing each physical link individually. Cost Efficiency: ✓ Instead of upgrading to higher-speed interfaces, organizations can combine multiple lower-speed interfaces to achieve the desired performance at a lower cost. 3. Configuring Link Aggregation on Switches ✓ There are two main protocols used to configure and manage Link Aggregation: LACP (Link Aggregation Control Protocol) and PAgP (Port Aggregation Protocol). These protocols help switches automatically negotiate and manage the creation of an EtherChannel. a. LACP (Link Aggregation Control Protocol) - IEEE 802.3ad ✓ LACP is an open standard protocol defined by IEEE (802.3ad) that allows multiple physical Ethernet links to be combined into a single logical link. It enables automatic negotiation and management of the aggregated links. How LACP works: ✓ Switches exchange LACP Data Units (LACPDUs) to negotiate which links will be active in the EtherChannel. ✓ LACP ensures that both switches agree on the links being aggregated and that they are functioning correctly. LACP Modes: ✓ Active Mode: The port actively tries to form an EtherChannel by sending LACP packets. ✓ Passive Mode: The port will not form an EtherChannel unless it receives LACP packets from another device in active mode. LACP Example Configuration on Cisco Switch: Switch(config)# interface range fastEthernet 0/1 - 2 Switch(config-if-range)# channel-group 1 mode active b. PAgP (Port Aggregation Protocol) ✓ PAgP is a Cisco proprietary protocol that automatically negotiates the formation of an EtherChannel between Cisco devices. How PAgP works: ✓ Similar to LACP, PAgP helps manage EtherChannel by exchanging PAgP packets between devices. It automatically detects and bundles links into an EtherChannel if both ends of the link agree. PAgP Modes: ✓ Desirable Mode: The port actively attempts to negotiate an EtherChannel by sending PAgP packets. ✓ Auto Mode: The port will form an EtherChannel only if it receives PAgP packets from a port in desirable mode. PAgP Example Configuration on Cisco Switch: Switch(config)# interface range fastEthernet 0/1 - 2 Switch(config-if-range)# channel-group 1 mode desirable c. Configuring Link Aggregation on Switches (General Steps) Step 1: Choose the interfaces for aggregation: ✓ Decide which physical interfaces (e.g., FastEthernet or GigabitEthernet ports) will be part of the EtherChannel. Step 2: Create the EtherChannel group: ✓ On each switch, assign the selected interfaces to a channel group using LACP or PAgP protocols. Step 3: Set the port-channel interface as trunk or access: ✓ Configure the logical port-channel interface to either carry multiple VLANs (trunk mode) or a single VLAN (access mode), depending on the network requirements. Step 4: Verify the configuration: ✓ Use the command show etherchannel summary or show port-channel to confirm that the EtherChannel has been successfully established and that all physical links are functioning as expected. Example of Configuring LACP on Two Cisco Switches: Switch 1: Switch1(config)# interface range fastEthernet 0/1 - 2 Switch1(config-if-range)# channel-group 1 mode active Switch1(config-if-range)# exit Switch1(config)# interface port-channel 1 Switch1(config-if)# switchport mode trunk Switch 2: Switch2(config)# interface range fastEthernet 0/1 - 2 Switch2(config-if-range)# channel-group 1 mode active Switch2(config-if-range)# exit Switch2(config)# interface port-channel 1 Switch2(config-if)# switchport mode trunk 4. Verification and Troubleshooting ✓ Verify EtherChannel Status: ✓ Use the following command to check the status and details of the EtherChannel: Switch# show etherchannel summary  LECTURE NOTE 5: Advance VLAN Configuration 1. VLAN Membership: Static vs. Dynamic VLAN membership defines how devices are assigned to specific VLANs within a network. There are two primary methods for VLAN membership: static and dynamic. a. Static VLAN Membership (Port-based VLANs) In a static VLAN, a device is manually assigned to a specific VLAN by configuring the switch port to which the device is connected. This method is also known as port-based VLAN configuration. The network administrator manually assigns a port to a specific VLAN. All traffic from the device connected to that port is tagged with the corresponding VLAN ID. Example, if Port 1 is assigned to VLAN 10, any device connected to Port 1 will belong to VLAN 10. Advantage ✓ Simple and easy to configure for small networks. ✓ Provides high control over which devices are assigned to specific VLANs. Disadvantage ✓ Not scalable for large networks with frequent device changes. ✓ Requires manual configuration if devices move between different network ports. Example of Configuration Switch(config)# interface fastEthernet 0/1 Switch(config-if)# switchport mode access Switch(config-if)# switchport access vlan 10 b. Dynamic VLAN Membership In a dynamic VLAN, the VLAN membership of a device is automatically determined based on the device’s MAC address. Dynamic VLAN Assignment relies on a VLAN Management Policy Server (VMPS). When a device connects to the switch, the switch queries the VMPS server to determine which VLAN the device should be assigned to, based on the device’s MAC address. The device is automatically placed into the correct VLAN, and no manual configuration on individual switch ports is needed. Advantages ✓ Ideal for environments where devices frequently move between ports (e.g., employees moving to different desks). ✓ Reduces the administrative burden of manually configuring VLAN assignments. Disadvantages ✓ More complex to set up compared to static VLANs. ✓ Requires a VMPS server, which adds to the cost and complexity of the network. Dynamic VLAN Process ✓ The device connects to the network. ✓ The switch queries the VMPS server with the device’s MAC address. ✓ The VMPS server responds with the appropriate VLAN assignment. ✓ The switch dynamically assigns the port to the correct VLAN. 2. VLAN Management VLAN management involves configuring, monitoring, and maintaining VLANs within a network. Proper VLAN management ensures that the network is segmented effectively and operates securely and efficiently. a. VLAN Naming and Documentation VLAN Naming: ✓ Each VLAN should have a clear, descriptive name that reflects its purpose (e.g., HR_VLAN, SALES_VLAN). ✓ This improves network visibility and helps administrators easily identify the VLANs in use. Documentation: ✓ Documenting the VLAN configuration is critical for future network management. It includes the VLAN IDs, names, ports associated with each VLAN, and any dynamic VLAN policies. ✓ Having well-maintained documentation prevents errors and simplifies troubleshooting. b. VLAN Trunking and Management Across Switches Trunk Links: ✓ Trunk links allow traffic from multiple VLANs to pass between switches. A trunk port is configured to carry traffic for all or specific VLANs using 802.1Q VLAN tagging. ✓ A single physical link can carry multiple VLANs, which is essential in larger networks with many interconnected switches. Management of VLANs Across Multiple Switches:  ✓ VLAN configurations must be consistent across switches to maintain proper network segmentation. ✓ VLAN information is propagated using protocols like VTP (VLAN Trunking Protocol), which helps manage VLAN configuration across the entire network. c. VLAN Trunking Protocol (VTP) ✓ VTP is used to propagate VLAN configurations automatically across multiple switches within the same VTP domain. It simplifies VLAN management in larger networks. VTP Modes: ✓ Server Mode: The switch can create, modify, and delete VLANs. Changes made on a VTP server are propagated to all other switches in the VTP domain. ✓ Client Mode: The switch receives VLAN information from VTP servers but cannot make changes. ✓ Transparent Mode: The switch does not participate in the VTP domain but forwards VTP advertisements between other switches. VTP Configuration : Switch(config)# vtp mode server Switch(config)# vtp domain NetworkDomain Switch(config)# vtp password securepassword d. VLAN Security and Best Practices VLAN Hopping Attack Prevention: ✓ VLAN hopping is a security exploit where an attacker gains access to traffic in different VLANs. ✓ Best practices include disabling unused switch ports and ensuring trunk ports are properly configured (limiting allowed VLANs). Best Practices: ✓ Disable unused ports: Shut down unused switch ports to prevent unauthorized access. ✓ Limit VLANs on trunk ports: Only allow necessary VLANs on trunk links to minimize security risks. ✓ Use Native VLAN carefully: The native VLAN should be used cautiously as it transmits untagged frames. Consider changing it from the default VLAN 1 to a less frequently used VLAN for security purposes.  Lecture Note 6 Part 2 : Configuration of EtherChannel using PAgP in Cisco Packet Tracer Scenario: ✓ We will configure two switches, Switch 1 and Switch 2, to use PAgP for EtherChannel. ✓ Two interfaces (FastEthernet 0/1 and FastEthernet 0/2) on each switch will be bundled into a single logical EtherChannel. 1. Topology Setup: ✓ Create the topology in Packet Tracer: ✓ Add two switches (Switch 1 and Switch 2). ✓ Connect the two switches using two cables: ✓ FastEthernet 0/1 on both switches. ✓ FastEthernet 0/2 on both switches. 2. Configuring PAgP on Switch 1: ✓ Enter privileged mode: Switch1> enable ✓ Enter global configuration mode: Switch1# configure terminal ✓ Select the interfaces you want to bundle into the EtherChannel: ✓ Use FastEthernet 0/1 and FastEthernet 0/2. Switch1(config)# interface range fastEthernet 0/1 - 2 ✓ Create an EtherChannel using PAgP in desirable mode: ✓ The desirable mode actively negotiates the EtherChannel with the other switch. Switch1(config-if-range)# channel-group 1 mode desirable ✓ Set the logical port-channel interface as a trunk: ✓ After creating the EtherChannel, a Port-Channel 1 interface is automatically created. Configure this port-channel interface as a trunk to carry multiple VLANs. Switch1(config-if-range)# exit Switch1(config)# interface port-channel 1 Switch1(config-if)# switchport mode trunk 3. Configuring PAgP on Switch 2: Switch2> enable ✓ Enter global configuration mode:  Switch2# configure terminal ✓ Select the interfaces you want to bundle into the EtherChannel: Switch2(config)# interface range fastEthernet 0/1 - 2 ✓ Create an EtherChannel using PAgP in auto mode: ✓ The auto mode will wait for a PAgP request from the other side (in this case, Switch 1) to form the EtherChannel. Switch2(config-if-range)# channel-group 1 mode auto ✓ Set the logical port-channel interface as a trunk: Switch2(config-if-range)# exit Switch2(config)# interface port-channel 1 Switch2(config-if)# switchport mode trunk 4. Verification: On Switch 1, verify that the EtherChannel has been successfully created: Switch1# show etherchannel summary ✓ You should see Port-Channel 1 with FastEthernet 0/1 and FastEthernet 0/2 as part of the EtherChannel. ✓ The status should indicate that the EtherChannel is functioning correctly (ports are in P or U states). On Switch 2, verify the EtherChannel status: Switch2# show etherchannel summary ✓ Similarly, you should see Port-Channel 1 with the associated physical interfaces.  LECTURE NOTE 8: Dynamic Routing Protocols I (RIP) 1. Introduction to RIP (Routing Information Protocol) RIP (Routing Information Protocol) is one of the oldest and simplest distance-vector dynamic routing protocols used in computer networks. It enables routers to automatically share routing information and update their routing tables, allowing dynamic discovery of routes across a network. Distance-Vector Protocol: RIP calculates the best path to a destination based on the hop count (the number of routers a packet must pass through to reach the destination). Hop Count Limit: RIP uses a maximum hop count of 15. If the hop count exceeds 15, the destination is considered unreachable. Version: RIP has two main versions: RIP v1: Classful routing (no support for subnetting or CIDR). RIP v2: Classless routing (supports subnetting and CIDR, and includes authentication). Updates: RIP routers send out routing updates every 30 seconds, sharing their routing tables with neighboring routers. Working Principle: ✓ Routers using RIP broadcast their entire routing table to their neighbors. ✓ Each router selects the path with the fewest hops to a destination network and updates its routing table accordingly. ✓ If a route becomes unreachable (e.g., a link failure), RIP removes it after 180 seconds of inactivity. 2. Configuring RIP ✓ Configuring RIP is straightforward. Step-by-Step RIP Configuration: ✓ Topology Overview: We have two routers: Router 1 and Router 2, each with its own local network. Router 1 Router 2 192.168.1.0/24 (connected to PC1) 192.168.2.0/24 (connected to PC2) 10.0.0.0/30 (connected to Router 2) 10.0.0.1/30 (connected to Router 1) ROUTER 1: ✓ Step 1: Access Router Configuration Mode ✓ Enter privileged EXEC mode: Router> enable  ✓ Enter global configuration mode: Router# configure terminal Step 2: Enable RIP ✓ Enter RIP routing configuration mode: Router(config)# router rip ✓ Specify RIP version 2 (recommended for modern networks): Router(config-router)# version 2 ✓ Step 3: Configure Networks for RIP ✓ Specify the network that the router is directly connected to (e.g., 192.168.1.0/24): Router(config-router)# network 192.168.1.0 ✓ Also, specify the network connecting to the other router (e.g., 10.0.0.0/30): Router(config-router)# network 10.0.0.0 ✓ Step 4: Exit RIP Configuration ✓ Exit RIP routing mode: Router(config-router)# exit ✓ Step 5: Save the Configuration ✓ Save the running configuration to the startup configuration: Router# write memory ROUTER 2: ✓ Step 6: Repeat on the Other Router ✓ Follow the same process to configure RIP on Router 2, ensuring the correct networks are added: ✓ network 192.168.2.0 ✓ network 10.0.0.0 ✓ Step 7: Verification ✓ Check the routing table on both routers to verify that RIP has learned routes: Router# show ip route ✓ Ping between devices on different networks (e.g., PC1 to PC2) to ensure connectivity. 3. Advantages and Limitations of RIP Advantages of RIP: Simplicity: ✓ Easy to configure, making it suitable for small networks. ✓ Requires minimal configuration commands compared to more advanced protocols like OSPF or EIGRP. Widely Supported: ✓ RIP is supported on almost all router brands and models due to its age and simplicity. Loop Avoidance (Split Horizon & Route Poisoning): ✓ RIP implements mechanisms like split horizon and route poisoning to avoid routing loops. Automatic Updates: ✓ RIP dynamically updates routing tables through periodic broadcasts, adjusting to network changes without manual intervention. Limitations of RIP: Scalability: ✓ RIP has a maximum hop count of 15, which makes it unsuitable for large networks or complex topologies with many routers. After 15 hops, a network is considered unreachable. Slow Convergence: ✓ RIP’s update interval is 30 seconds, and it can take up to 180 seconds to remove an unreachable route, making it slower to respond to network changes compared to other protocols. Bandwidth Usage: ✓ RIP sends the entire routing table in updates every 30 seconds, which can consume significant bandwidth in larger networks. No Support for VLSM in RIP v1: ✓ RIP v1 is classful, which means it doesn't support Variable Length Subnet Masking (VLSM) or Classless Inter-Domain Routing (CIDR). This limits IP address efficiency in modern networks. RIP v2 resolves this but is still less efficient than more advanced protocols.  Lecture Note 5 Part 2 - Basic VTP (VLAN Trunking Protocol) Scenario: ✓ We will configure Switch 1 as a VTP Server and Switch 2 as a VTP Client. ✓ VTP will be used to propagate VLANs created on the server to the client. ✓ Both switches will be connected via a trunk link. ________________________________________ 1. Topology Setup: Create the topology: ✓ Add two switches (Switch 1 and Switch 2) in Packet Tracer. ✓ Connect the two switches using a FastEthernet interface (e.g., FastEthernet 0/1 on both switches). ✓ Optionally, you can add a PC to each switch and configure VLANs for those PCs, but it’s not required for the basic VTP configuration. 2. Configure Switch 1 as VTP Server: ✓ Enter privileged mode: Switch1> enable ✓ Enter global configuration mode: Switch1# configure terminal ✓ Set the switch to VTP server mode (this is the default mode, but it’s good practice to set it explicitly): Switch1(config)# vtp mode server ✓ Set the VTP domain name (all switches in the same VTP domain will share VLAN information): Switch1(config)# vtp domain NetworkDomain ✓ Set a VTP password (optional but recommended for security): Switch1(config)# vtp password cisco123 ✓ Create VLANs on the server (these will be propagated to other switches): Switch1(config)# vlan 10 Switch1(config-vlan)# name HR_VLAN Switch1(config)# vlan 20 Switch1(config-vlan)# name IT_VLAN Switch1(config)# exit ✓ Configure the trunk link on the interface that connects to the client switch: Switch1(config)# interface fastEthernet 0/1 Switch1(config-if)# switchport mode trunk Switch1(config-if)# switchport trunk allowed vlan all 3. Configure Switch 2 as VTP Client:  ✓ Enter privileged mode: Switch2> enable ✓ Enter global configuration mode: Switch2# configure terminal ✓ Set the switch to VTP client mode: Switch2(config)# vtp mode client ✓ Set the VTP domain name (must match the server’s domain): Switch2(config)# vtp domain NetworkDomain ✓ Set the same VTP password as the server: Switch2(config)# vtp password cisco123 ✓ Configure the trunk link on the interface that connects to the server switch: Switch2(config)# interface fastEthernet 0/1 Switch2(config-if)# switchport mode trunk Switch2(config-if)# switchport trunk allowed vlan all 4. Verify the VTP Configuration: ✓ On Switch 2 (the client switch), check that the VLANs created on Switch 1 have been propagated: Switch2# show vlan brief ✓ You should see VLAN 10 (HR_VLAN) and VLAN 20 (IT_VLAN) in the VLAN database on Switch 2, even though they were not manually created on Switch 2. ✓ Check the VTP status on both switches: Switch1# show vtp status Switch2# show vtp status ✓ This will display the VTP version, domain name, mode (server or client), and the number of VLANs configured.  LECTURE NOTE 9: DYNAMIC ROUTING PROTOCOLS II 1. Introduction to OSPF (Open Shortest Path First) OSPF (Open Shortest Path First) is a widely used dynamic routing protocol that operates within a single autonomous system (AS). It is a link-state protocol, meaning it builds a map (or topology) of the network and calculates the shortest path to each destination based on that map. ✓ Link-State Protocol: Unlike distance-vector protocols (like RIP), which only know about their neighbors, OSPF routers have a full understanding of the network topology. Each router shares its view of the network (called link-state information) with all other routers in the same area, allowing for precise and efficient routing. ✓ Metric: OSPF uses cost as its metric to determine the best path to a destination. Cost is typically based on the bandwidth of the link — the higher the bandwidth, the lower the cost. ✓ Fast Convergence: OSPF responds quickly to network changes (e.g., a link failure), which is one of its main advantages over protocols like RIP. ✓ Scalable: OSPF supports both small and large networks, making it suitable for large enterprise environments. 2. OSPF Areas and LSAs ✓ OSPF introduces the concept of areas to optimize and manage routing in larger networks. This hierarchical structure helps keep the OSPF routing tables small and reduces the amount of routing information that needs to be processed. OSPF Areas: ✓ Backbone Area (Area 0): The central area of an OSPF network. All other areas must connect to Area 0, and it's responsible for forwarding inter-area traffic. ✓ Non-Backbone Areas: These are other areas connected to Area 0. Examples include: ✓ Regular Areas: Normal OSPF areas that exchange routing information with Area 0. ✓ Stub Areas: Areas that reduce routing information by blocking external routes. ✓ Totally Stubby Areas: Further reduce routing information, limiting the routes received from other areas. LSAs (Link-State Advertisements): ✓ OSPF routers exchange LSAs to share information about their links (interfaces), directly connected routers, and reachable networks. LSAs are the building blocks that OSPF uses to create a full view of the network topology. ✓ Type 1 LSA: Sent by routers to describe their directly connected links within an area. ✓ Type 2 LSA: Sent by designated routers to describe the routers on a shared network segment (like a LAN). ✓ Type 3 LSA: Used to summarize routes between different areas (ABR – Area Border Routers).  ✓ Type 5 LSA: Describes external routes (routes outside the OSPF domain, redistributed from other routing protocols like RIP or BGP). 3. Configuring OSPF Configure OSPF on a Cisco router in a basic network topology. Router 1 Router 2 Router 3 Network 192.168.1.0/24 Network 192.168.2.0/24 Network 192.168.3.0/24 Network 10.0.0.0/30 (to R2) Network 10.0.0.1/30 (to R1) Network 10.0.0.2/30 (to R2) Step-by-Step OSPF Configuration: ✓ Step 1: Access the Router ✓ Enter privileged EXEC mode: Router> enable ✓ Enter global configuration mode: Router# configure terminal Step 2: Enable OSPF ✓ Start OSPF process: ✓ OSPF is identified by a process ID (any number, typically 1 is used). Router(config)# router ospf 1 Step 3: Assign Networks to OSPF ✓ Specify the networks and areas for OSPF: ✓ The network command is used to add the router’s interfaces to OSPF. ✓ You must define the network, wildcard mask (inverted subnet mask), and area number. ROUTER 1 (Connected to 192.168.1.0/24 and 10.0.0.0/30 networks): Router(config-router)# network 192.168.1.0 0.0.0.255 area 0 Router(config-router)# network 10.0.0.0 0.0.0.3 area 0 ROUTER 2 (Connected to 192.168.2.0/24 and 10.0.0.0/30 networks): Router(config-router)# network 192.168.2.0 0.0.0.255 area 0 Router(config-router)# network 10.0.0.0 0.0.0.3 area 0 ROUTER 3 (Connected to 192.168.3.0/24 and 10.0.0.0/30 networks): Router(config-router)# network 192.168.3.0 0.0.0.255 area 0 Router(config-router)# network 10.0.0.0 0.0.0.3 area 0 Step 4: Save Configuration ✓ Save the running configuration to the startup configuration: Router# write memory Step 5: Verification ✓ Verify the OSPF routing table: ✓ Use the show ip route command to see if the router has learned OSPF routes: Router# show ip route ospf ✓ Check OSPF neighbors: ✓ Verify the OSPF neighbor relationships by using the following command: Router# show ip ospf neighbor  LECTURE NOTE 7: BASIC ROUTING 1. Introduction to Routing ✓ Routing is the process by which data packets are forwarded from one network to another. Routers are devices that direct this traffic by determining the best path for the data to travel. The primary function of routing is to enable communication between different networks, ensuring that data is sent from the source to the correct destination. ✓ Router: A networking device that forwards data packets between computer networks. ✓ Routing Table: A data table stored in a router or networked computer that lists the routes to particular network destinations. 2. Static vs. Dynamic Routing Static Routing: ✓ In static routing, routes are manually configured by the network administrator. ✓ The router uses a predefined path for forwarding packets. This route does not change unless manually modified. Advantages: ✓ Simple to implement in small networks. ✓ Provides full control over the path that packets take. Disadvantages: ✓ Manual configuration can be time-consuming, especially in large networks. ✓ Lack of adaptability: If a link fails, static routes do not automatically adjust. Example Command: Router(config)# ip route Dynamic Routing: ✓ In dynamic routing, routers automatically learn and adjust to changes in the network by using routing protocols. ✓ These protocols help routers exchange information and determine the best path based on the network's current state. Advantages: ✓ Automatically adjusts to changes in the network (e.g., if a link fails, the router finds an alternative route). ✓ Scalable, making it suitable for large networks. Disadvantages: ✓ More complex than static routing. ✓ Requires more processing and network resources. 3. Overview of Routing Protocols There are several common dynamic routing protocols used in networking. These protocols enable routers to communicate and exchange routing information to determine the best path for data. RIP (Routing Information Protocol): ✓ Type: Distance-vector protocol. ✓ Metric: Hop count (maximum of 15 hops). ✓ Features: Simple and easy to configure, but less efficient for large networks due to its 15-hop limit. ✓ Version: RIP v1 (classful) and RIP v2 (classless, supports subnet masks). Key Characteristics: ✓ Updates routing tables every 30 seconds. ✓ Not suitable for larger networks due to slow convergence and limited hop count. OSPF (Open Shortest Path First): ✓ Type: Link-state protocol. ✓ Metric: Cost, which is based on bandwidth. ✓ Features: Efficient for larger networks and provides fast convergence. ✓ Operation: Each router has a complete map (topology) of the network and uses the shortest path algorithm to determine the best path. ✓ Scalability: Works well in complex networks, supports variable-length subnet masks (VLSM) and is classless. Key Characteristics: ✓ Hierarchical design using areas to reduce overhead. ✓ Faster convergence compared to distance-vector protocols. EIGRP (Enhanced Interior Gateway Routing Protocol): ✓ Type: Hybrid protocol (combines characteristics of distance-vector and link-state protocols). ✓ Metric: Bandwidth, delay, load, and reliability. ✓ Features: Cisco proprietary, very efficient and fast convergence. ✓ Scalability: Supports large networks and is classless, making it highly scalable. Key Characteristics: ✓ Uses the DUAL algorithm to ensure loop-free and optimal paths. ✓ Supports unequal-cost load balancing, allowing traffic to be spread across multiple links of different capacities.  BGP (Border Gateway Protocol): ✓ Type: Path-vector protocol. ✓ Metric: Based on attributes like AS path and next-hop. ✓ Features: Used to route between autonomous systems (AS) on the internet. ✓ Operation: It is used primarily for internet routing and is responsible for exchanging routing information between ISPs and large organizations. Key Characteristics: ✓ BGP is the backbone protocol of the internet. ✓ It’s highly configurable and uses policies to determine the best path, not just simple metrics like other protocols. 4. Configuring Static Routes ✓ Configure static routes between two routers to enable communication between two networks. Scenario: ✓ Router 1 is connected to Network A (192.168.1.0/24). ✓ Router 2 is connected to Network B (192.168.2.0/24). ✓ The two routers are connected to each other via a point-to-point connection with the network 10.0.0.0/30. ✓ We will configure static routes so that hosts in Network A can communicate with hosts in Network B, and vice versa. 1. Topology Setup: Devices: ✓ Two routers: Router 1 and Router 2 ✓ Two PCs: PC A (in Network A) and PC B (in Network B) Connections: ✓ Router 1 is connected to PC A via the FastEthernet 0/0 interface. ✓ Router 2 is connected to PC B via the FastEthernet 0/0 interface. ✓ Router 1 and Router 2 are connected via the Serial 0/0/0 interface. 2. IP Addressing: Device / Interface IP Address Subnet Mask Router 1 (FastEthernet 0/0) 192.168.1.1 255.255.255.0 Router 1 (Serial 0/0/0) 10.0.0.1 255.255.255.252 Router 2 (Serial 0/0/0) 10.0.0.2 255. 255.255.252 Router 2 (FastEthernet 0/0) 192.168.2.1 255.255.255.0 PC A 192.168.1.2 255.255.255.0 PC B 192.168.2.2 255.255.255.0 3. Step-by-Step Configuration: Step 1: Configuring IP Addresses ON ROUTER 1: ✓ Enter privileged EXEC mode: Router1> enable ✓ Enter global configuration mode: Router1# configure terminal ✓ Configure the FastEthernet 0/0 interface (connected to PC A): Router1(config)# interface fastEthernet 0/0 Router1(config-if)# ip address 192.168.1.1 255.255.255.0 Router1(config-if)# no shutdown ✓ Configure the Serial 0/0/0 interface (connected to Router 2): Router1(config)# interface serial 0/0/0 Router1(config-if)# ip address 10.0.0.1 255.255.255.252 Router1(config-if)# clock rate 64000 Router1(config-if)# no shutdown ✓ Exit configuration mode: Router1(config-if)# exit Router1(config)# exit ON ROUTER 2: ✓ Enter privileged EXEC mode: Router2> enable ✓ Enter global configuration mode: Router2# configure terminal ✓ Configure the FastEthernet 0/0 interface (connected to PC B): Router2(config)# interface fastEthernet 0/0 Router2(config-if)# ip address 192.168.2.1 255.255.255.0 Router2(config-if)# no shutdown ✓ Configure the Serial 0/0/0 interface (connected to Router 1): Router2(config)# interface serial 0/0/0 Router2(config-if)# ip address 10.0.0.2 255.255.255.252  Router2(config-if)# no shutdown ✓ Exit configuration mode: Router2(config-if)# exit Router2(config)# exit Step 2: Configuring Static Routes ✓ Configure static routes on each router so that they know how to reach the remote network. ON ROUTER 1: ✓ Enter global configuration mode: Router1# configure terminal ✓ Configure the static route to reach Network B (192.168.2.0/24): ✓ The next hop to reach this network is Router 2’s Serial 0/0/0 IP address (10.0.0.2). Router1(config)# ip route 192.168.2.0 255.255.255.0 10.0.0.2 ✓ Exit configuration mode: Router1(config)# exit ON ROUTER 2: ✓ Enter global configuration mode: ✓ Router2# configure terminal ✓ Configure the static route to reach Network A (192.168.1.0/24): ✓ The next hop to reach this network is Router 1’s Serial 0/0/0 IP address (10.0.0.1). Router2(config)# ip route 192.168.1.0 255.255.255.0 10.0.0.1 ✓ Exit configuration mode: Router2(config)# exit Step 3: Verifying the Configuration ✓ After configuring the static routes, you can use the following commands to verify the routing table and test the network connectivity: ✓ Check the routing table: ✓ On both routers, use the following command to check the static routes: Router# show ip route ✓ You should see the static route entries for the remote networks (192.168.1.0 and 192.168.2.0). ✓ Ping test from PC A to PC B: Summary of Static Route Commands: ON ROUTER 1: Router1> enable Router1# configure terminal Router1(config)# ip route 192.168.2.0 255.255.255.0 10.0.0.2 Router1(config)# exit ON ROUTER 2: Router2> enable Router2# configure terminal Router2(config)# ip route 192.168.1.0 255.255.255.0 10.0.0.1 Router2(config)# exit