cisco lan switching

-00-0C has a smaller oui--that is only 12 in number. As a result, your MGS will always be smaller than the MAC address of the catalyst switch you buy, so it will always win a root battle in the Cisco Network (as well as other networks on the planet). In other words, if you ignore the location layout of the root bridge, there are probably 1000 factors that can degrade your network throughput. Obviously, manually controlling your root bridge is criti

"Copyright notice: Original translation articles, translation level is limited, errors are unavoidable,The Translator is not responsible for the consequences of errors or omissions in the article, please be careful to reprint them. Reproduced please retain this statement and source: blog.csdn.net/shallnet, download the English version of the book "I have never known why Cisco Lan

each VLAN can have a different clock value. Cisco has two important hints for using an instance on each VLAN: Allows you to use many excellent features, such as load balancing and per-VLAN traffic. will make you miserable (if you don't know what you're doing). The goal now is to show you how to maximize 1th and avoid 2nd.In general, a multi-instance spanning tree gives you an amazing tool to control your network. It is important to

", describes some complex topics such as load balancing and minimizing convergence time. In this chapter, the term bridge, switch, and tier two switches are used interchangeably. While some argue that these terms vary widely between different types of devices, these differences are not affected when we discuss spanning trees, especially when discussing STP standards that have been completed prior to the development of hardware switches. For example, you will learn the concept of "Root Bridge" (w

only receives a frame with a source address of AA-AA-AA-AA-AA-AA on the port port1/2 and then changes its top Mac forwarding Address table entry to the wrong port! As the frame spins in the opposite direction (recalling that loop forwarding exists in two directions), you will see that the MAC address of the HOST-A will beswitch back and forth between Port 1/1 and Port 1/2. in short, not only the unicast ping package will continue to fill the entire network, and the bridge MAC address forw

1 Gbps 4 Ten Gbps 2 The values in table 6-1 are well thought out, so that the current and previous methodsare applicable to the bandwidth that is now commonly used. The key point about STP path cost values is to remember that "the smaller the overhead is the better". Remember 1. The X version to the 2.4 version of the Catalyst NMP uses the previous linear value calculation method, starting with the 3.1 release with the new cost value, al

root is not a normal command-it is a macro that affects other commands. In other words, Set Spantree root does not appear in the command result of Show config . For example, you run a macroset Spantree root 1, assuming that the current root bridge priority is greater than 8192, the macro automatically executes the set spantree priorities 1 8191 command. After the command set Spantree priority is written to NVRAM, there are no signs of using macros. despite Set Spantree root is just a macro, bu

are sent when the bridge receives better BPDUs.In addition, it also controls the transmission of BPDUs while "saving optimal BPDUs". When the bridge is first activated, all its ports start to send BPDUs every 2 seconds (if the default timer configuration is used), but if a port receives a BPDU from another bridge and the BPDU is better than the sent BPDU, the local port stops sending BPDUs. If a better BPDU is not sent from an adjacent bridge within a period of time (the default of 20 second

port belongs to a link only), and the number of each STP consists of table 6-2.Table 6-2. STP components in a Switch and 146 Segment Network STP Component number Root bridge 1 root port 14 Specify port 146 Also, all options are based on the following four-step comparison principle: Minimum root bridge bid Minimum root path overhead Minimum sender bid Minimum Po

and continue to "keep calling". However, if host-d tries to send a frame to host-e within 20 seconds (assuming HOST-E has not already sent the packet), the frame floods all the switch links, because the Ee-ee-ee-ee-ee-ee MAC address is no longer in the Address table. table 6-8 shows that three switches converge in the new topology and the data traffic is also restored after the entry of address Ee-ee-ee-ee-ee-ee in the MAC address table. Table 6-8. Bridge Table Value after topology change

State and its possible transition to. Figure 6-11. Possible Port states and TransitionsFigure 6-12 shows an example of a network port classification and status show, noting that all ports except CAT-C:PORT-1/2 are forwarding states. Figure 6-12. Sample Network with Port states identifiedTable 6-4 lists the shorthand symbol tables used in this book instead of the spanning tree state. Table 6-4. STP state and Port Symbols state/port symbol Block

timer should pay attention to two points. 1th, change the timer default time value before you have to deliberate, in this chapter seventh has more detailed discussion. 2nd, even if you are confident about the timer adjustment, you should only modify the timer on the root bridge. As you will see in the following section, the BPDU contains three timer fields, which are passed through three fields to pass the timer value to the rest of the networkAllNetwork Bridge. Consider the other case, each br

disabled 1/2 1 forwarding disabled Multiple domains fully illustrate that Cat-3 is the root bridge: The root ports are port 1/0. Note that the catalyst 4000s,5000s,6000s is not labeled as a 1/0 physical port, and the NPM software uses a reference to the logical control port, SC0, as a "logical root port". Local bid and Root bridge bid match. Root Path Cost is 0. Timer value matches. All ports are in the forwarding state. Look for the end--the root br

We have discussed a variety of LAN segmentation methods (LAN technology-based LAN segmentation). Now we should carefully study the LAN switching technology. Although layer-3 switching is also used, This article focuses on the trad

Cisco LAN switches are still commonly used. So I studied the maintenance and configuration problems of Cisco LAN switches. I would like to share them with you here, hoping to help you. Cisco LAN switches have evolved from a HUB-ba

Tags: HSRP working principle STP effect ACL access control List loop storm Cisco private protocolDay 031. What is HSRP? How does it work?HSRP: Hot Standby Routing protocolHSRP is a Cisco private protocol that ensures that user communication can be quickly and transparently restored when a network edge device or access link fails.This provides redundant rows for the IP network. By using the same virtual IP a

A typical LAN refers to a core switch with a three-layer switching function to connect several branch switches (not necessarily three-layer switching capabilities). We assume that the core switch name is: COM, branch switches are: par1, PAR2, PAR3, respectively, through the port 1 Ray module with the core switch, and assume the VLAN name is counter, market, manag

Overview of LAN switches LAN switches have evolved from a HUB-based LAN shared in the traditional sense to a broader space. Take Cisco's Catalyst 5000 Series LAN switch as an example. It includes an integrated switching hardware structure, 10-Mbps Ethernet that supports

Tags: routing switching technology HSRP working principle three-layer Exchange STP function DHCP serviceFirst, the questionDay 011. What is a Vlan? What does VLAN do? is the interface of the default switch in that VLAN? What kind of Vlan??2. What is Trunk? What is the mode of Trunk? How to negotiate?3. What is the role of EtherChannel?4. What is DHCP? What is the role of DHCP?Day 021. What is the three layer Exchange? What is the difference between a

protocol between as is called the External Gateway Protocol External Gateway Protocol (also called Inter-Domain routing protocol): there are two types of inter-domain routing protocols: externalGateway Protocol (EGP) and Border Gateway Protocol (BGP)2) Dynamic routing according to the algorithm can be divided into: Distance vector routing protocol, link state routing protocolDistance Vector Routing protocol: Select Route RIP,IGRP based on the number of routes that are routed from the source net