CCNP Switch Notes VLAN Implementation VLANs are used to break large campus networks into smaller pieces. The benefit of this is to minimize the amount of broadcast traffic on a logical segment. VLAN Overview A virtual LAN (VLAN) is a logical LAN, or a logical subnet. It defines a broadcast domain. A physical subnet is a group of devices that shares the same physical wire. A … [Read more...]
CCNP Switch Notes Campus Network Design
CCNP Switch Notes Campus Network Design Campus Network Design An enterprise campus generally refers to a network in a specific geographic location. It can be within one building or span multiple buildings near each other. A campus network also includes the Ethernet LAN portions of a network outside the data center. Large enterprises have multiple campuses connected by a WAN. … [Read more...]
CCNP Switch Notes Spanning Tree
CCNP Switch Notes Spanning Tree Ethernet network design balances two separate imperatives. First, Ethernet has no capacity for detecting circular paths. If such paths exist, traffic loops around and accumulates until new traffic is shut out. (This is called a broadcast storm.) Second, having secondary paths is good preparation for inevitable link failure. Spanning Tree is a … [Read more...]
CCNP Switch Notes Wireless LANs in a Campus Network
CCNP Switch Notes Wireless LANs in a Campus Network Wireless LANs (WLAN) transmit and receive data using radio or infrared signals, sent through an access point (AP), and are not usually required to have radio frequency (RF) licenses. WLANs are local to a building or a campus and are an extension of the wired network. Cisco Unified Wireless Network The Cisco Unified Wireless … [Read more...]
CCNP Switch Notes Voice and Video in a Campus Network
CCNP Switch Notes Voice and Video in a Campus Network Voice over IP (VoIP) has become common in the business world, and now Video over IP is becoming more integrated into networks. Neither should be added to a network without advance planning to ensure good voice and video quality. Some benefits of converging voice, video, and data networks include: Consolidating network … [Read more...]
CCNP Switch Notes Campus Network Security
CCNP Switch Notes Campus Network Security Attention has traditionally been paid to network perimeter security, such as firewall, and to mitigating Layer 3 attacks.However, networks must be protected against Layer 2 attacks, too. These are launched from devices inside the network by either a rogue device or a legitimate device that has been compromised. Rogue devices might be … [Read more...]
CCNP Switch Notes First Hop Redundancy
CCNP Switch Notes First Hop Redundancy Specifying a default gateway leads to a single point of failure. Proxy Address Resolution Protocol (ARP) is one method for hosts to dynamically discover gateways, but it has issues in a highly available environment. With Proxy ARP: Hosts ARP for all destinations, even remote. Router responds with its MAC. Problem: Slow failover … [Read more...]
CCNP Switch Notes Implementing High Availability
CCNP Switch Notes Implementing High Availability A highly available network is the goal of every network engineer. Having a highly available network makes the job easier because it helps to prevent network outages and minimize downtime. Components of High Availability There are five components to high availability: redundancy, technology, people, processes, and tools. The … [Read more...]
CCNP Switch Notes InterVLAN Routing
CCNP Switch Notes InterVLAN Routing VLANs divide the network into smaller broadcast domains but also prohibit communication between domains. To enable communication between those groups–without also passing broadcasts–routing is used. InterVLAN Routing Using an External Router A Layer 2 switch can connect to a router to provide reachability between VLANs. This can be done … [Read more...]