网络管理的误解:第2期

This paper is the second in a series where we look at common misconceptions about network management through the real-life experiences of various companies. 每期的目的都是为了揭示网络风险因素, 用例子量化这些风险, and—most importantly—give you the prescription to keep your network from becoming terminal to your business. 本期, 我们讨论网络问题的一个常见原因, 双工不匹配, which is potentially disasterous if not identified and corrected quickly.

网络不稳定的危险
Businesses today rely on bandwidth-intensive and latency-sensitive enterprise applications such as VoIP, 流媒体, CRM, ERP, PDM, 或大量的SaaS应用程序，如Salesforce.com. 他们建立与互联网相连的贸易或合作伙伴网络, where any delays in transactions can ripple work stoppages and cost overruns throughout numerous organizations. 因此，发现不稳定的共同原因至关重要.

一个网络是否十大赌博正规老平台于一个建筑物, 多个校园, 或者是全球各地的分部, instability usually is caused by misconfiguration or unknown change. The dynamic nature of mobility technologies and network access technologies today makes these issues less obvious and more insidious.

双工不匹配对制造企业造成严重破坏
A surprisingly persistent and ubiquitous problem occurring in most networks is 双工不匹配 between system NICs and their associated switch port. In more than 90% of the customer proof of concepts Entuity has completed, our network management solution has identified 双工不匹配es that had gone unaddressed for weeks or months. The potential impact and ensuing cost is compounded since performance issues from a 双工不匹配 often don’t show up under light load. When the load increases and the users are pushing the service heavily, that’s when performance will be massively impacted—just when they need it most. 而且大多数事务都是基于TCP的, the retry mechanisms will eventually allow the transactions to succeed, 但很, 非常缓慢.

Identifying and correcting 双工不匹配es is also not a one-time, “set and forget” task. It’s an ongoing issue in the fluid, constantly evolving enterprise infrastructure of today.

Take for example a high-tech manufacturing company that was performing maintenance on their corporate application servers. Their Microsoft Exchange server needed requisite updates of security patches, so the operations team scheduled down time for 3:00 AM on a Saturday to minimize impact on the user community. 打补丁和更新 went without a hitch, the server rebooted successfully, and everyone went home happy.

然而到了周一早上，气氛就不那么轻松了. As the wave of business users sat down at 8:00 AM with their cup of coffee to check their email, 呼叫中心被可怕的投诉淹没了, “the network is slow and Outlook says the connection to the Exchange server is lost!意识到大多数问题都是变化的结果, and that the security patches were the last change made to the server, operations staff quickly uninstalled them and rebooted (running without important security patches, 这使得网络处于高风险之中). But even as the staff began to breath a sigh of relief, the calls kept coming in.

在这一天结束之前, five IT technicians spent half a day troubleshooting the problem while the user community waited. The final fix was to swap out the server with a spare and relegate the original server to off-hour file backup alone. 这也没有奏效. 出什么事了?? It wasn’t until weeks later when they upgraded their open-source network monitoring tools for Entuity that were they able to immediately identify the true cause of this problem. 对双工不匹配问题非常敏感, Entuity alerted the network manager that the NIC reverted to halfduplex state during the server reboot, 导致与交换机不兼容. 根本不是安全补丁的问题.

企业如何识别双工不匹配
Entuity’s advanced Event Management System (EMS) and comprehensive reporting capabilities allow it identify 双工不匹配es in multiple ways. First, if a port duplex setting changes, Entuity raises an event that indicates the change. 第二个, 如果端口双工设置没有改变, Entuity can identify 双工不匹配es through a Port Inbound Fault “Incident,，这可能表明可能存在双工不匹配. (An Incident is a collection of events that help prevent event storms and add focus to situations that may impact business services.)
Finally, Entuity can identify mismatches using its embedded Report Builder. 在下面的图中, a tabular inventory report displays only those ports that were configured for half-duplex operation. 鉴于端口通常配置为全双工操作, 这可能表示双工不匹配, 并需要进一步调查.

Summary
对于一家高科技制造公司来说, 数百小时的IT时间来卸载补丁, 换出十大赌博正规老平台器, and finally reinstalling the patches could have been saved if they had been using Entuity. 企业的综合EMS和深度, actionable reporting capabilities ensure that organizations have the immediate insight they need to quickly get to the real cause of problems before disaster strikes.

关于ENTUITY
企业免去了网络管理的工作. 我们的高度自动化, unified enterprise-class solution puts deep network insight at your fingertips, frees IT staff to focus on strategic projects and easily integrates with major frameworks and networking environments. Entuity’s support and services teams are frequently praised for their rapid response, 网络专业知识和参与特殊活动. Founded in 1997 by two senior-level IT executives from the financial industry, Entuity总部设在伦敦，美国业务设在波士顿. 欲了解更多信息，请访问entuity.com.