What is IGMP Snooping

What does IGMP Snooping Do IGMP snooping is used to monitor the traffic of IGMP protocol between hosts and multicast-enabled routers. The switch uses it to learn which interface has an interested receiver and forward multicast traffic only to these interfaces. This feature could save bandwidth by allowing it to send traffic only needed, rather than flooding all multicast packets to all interfaces. IGMP Snooping and Forwarding Interfaces To determine how to forward multicast traffic, IGMP snooping maintains a “table” about the interfaces information:


在讨论无线的时候,通常都会问到:“瘦AP都有些什么功能?” 或者 “AP和WLC各负责什么?” 瘦AP一般的功能包括: Real-Time 802.11/MAC Functionality: Beacon Generation Probe Response Power management/Packet buffering 802.11e/WMM scheduling, queueing MAC

CCIE Data Center Online Resources and Reading List

Install, Config and Troubleshoot Guides Install, Config and Troubleshoot Guide for Cisco Nexus 7000 NXOS Switch Install, Config and Troubleshoot Guide for Cisco Nexus 5000 NXOS Switch Install, Config Guide for Cisco Nexus 2000 NXOS SwitchInstall, Configure and Troubleshoot Guide for Cisco Nexus 1000v NXOS Virtual SwitchInstall, Config and Troubleshoot Guide for Cisco MDS SAN NXOS SwitchInstall, Config and Troubleshoot Guide for Cisco ACE 4710 ApplianceCisco NX-OS FCoE Configuration Guide for Nexus 7000 and MDS 9500Install, Config and Troubleshoot guide for Cisco UCS ManagerInstall and Config Guide for Data Center Network Manager (DCNM)Configuration examplesCisco Nexus 7000 NXOS Config ExamplesCisco Nexus 5000 NXOS Config ExamplesCisco Nexus 1000v NXOS Config ExamplesCisco MDS SAN Switches NXOS Config ExamplesCisco UCS Manager Config ExamplesWhite Papers and Other Useful Online ResourcesCisco Product Support Documentation a central repository for all Cisco Documentation (by product or technology) - formerly known as Documentation CD, or CCO Documentation.

Walkthrough of CheckIO Inside Block

After a long absence, I returned to continue playing CheckIO tasks by a notification mail. The UI had been optimized a lot and the tasks were still as interesting as the before. Inside Block required checking whether a given point is inside a polygon or not. After some research on google, I found a practical method. How to check if a given point is in a polygon Given a polygon and a point ‘p’, find if ‘p’ lies inside the polygon or not.

The number of management nodes is important, take it into your consideration

The reason behind why I almost instantly became a big fan of Cisco FEX and satellite card technology is that, both of them provide tremendous complexity reduction in many aspects, like planning, managing, deploying and even the knowledge requirements for engineers. I think no one would argue that there are a lot of great tools from CLI to GUI or whole sets of applications can improve the engineer’s work effectiveness and efficiency.

What is hot/cold aisle in data center

A hot/cold aisle is a layout design for server racks in a data center. The goal of it is to increase the effectiveness of the cooling system by managing airflow in a data center. In the simplest form, this design involves lining up server racks in different rows with cold air facing one way and hot exhausts facing the other. Typically, cold aisles, which are usually composed of rack fronts, face AC output, and hot aisles face return ducts.

NO-NAT configuration on Cisco ASA Firewall

Cisco ASA firewall has upgraded its command line at the version 8.3 and changed a lot of configurations from their previous style. I recently faced two cases about NO-NAT in both version and want to leave a quick note here. Example details: inside IP address: outside IP address: traffic go through from inside interface to outside interface Before 8.3 An access-list is needed to filter the interested traffic.

Copy/Paste in Quick Look on MacOS

Quick Look, which is triggered by tapping space bar, of Mac OS system is the first feature that has impressed me since I switched from Windows to Mac years ago. This feature has saved me uncountable time for my from opening applications to open a file. Here is how to do copy/paste in quick look if you want to make it more powerful: But the default setting does’t allow you to select the quick looked file.

如何在Ubuntu 14.04上安装openDCIM 3

English version link openDCIM简介 openDCIM是一个免费且开源的数据中心(你也可以说“机房”这个名词=_=)基础网络管理软件。基础网络管理对于不

Tsukkomi about Chinese Cable SP Providers

Companies usually take experiences from others in the same industry or the ones share a lot of characters. This is also similar to Chinese companies in cable SPs. Every time I heard about what they wanted to learn from when we were discussing future business development, Comcast is always the one they like. But from my personal view, I prefer to consider this is an error to position themselves like Comcast because there are no share characteristics except for being called cable SPs.