艾倫的Memo與足跡

http://lamspeople.epfl.ch/kirrmann/Pubs/IEC_62439-1/IEC_62439_Summary.pdf Media Redundancy Protocol  (MRP) is a data network protocol standardized by the  International Electrotechnical Commission  as IEC 62439-2. It allows rings of  Ethernet  switches to overcome any single failure with recovery time much faster than achievable with  Spanning Tree Protocol . [1]  It is suitable to most  Industrial Ethernet  applications. https://en.wikipedia.org/wiki/Parallel_Redundancy_Protocol Parallel Redundancy Protocol  ( PRP ) is a network  protocol  standard for  Ethernet  that provides seamless  failover  against failure of any network component. This redundancy is invisible to the application. PRP nodes have two ports and are attached to two separated networks of similar topology. PRP can be implemented entirely in software, i.e. integrated in the network driver. Nodes with single attachment can be attach...

摘自:  https://en.wikipedia.org/wiki/Link_aggregation http://blog.xuite.net/zerofirst/blog/239023010-LACP+(Link+Aggregation+Control+Protocol) + All sorts of things about LACP and LAGs http://networkingbodges.blogspot.tw/2012/12/all-sorts-of-things-about-lacp-and-lags.html EtherChannel(PAgP 、 LACP) 基本配置 http://blog.sina.com.cn/s/blog_635e1a9e01017msv.html 在一般伺服器或者交換機的網路在大量傳輸過程會遭遇到瓶頸，通常要解決這種問題直觀方式就是儘可能的加大每條 channel 的頻寬囉～   但每個 Port 的上線頻寬都是固定的阿！所以就有人提出所謂的「 Trunking 」的概念。         Trunking 意即為將幾條 port channel 「邏輯的」想像成合併成一條大的 channel 。好比從甲地開車到乙地原本是只有一條單行道可以通行（一個 port ）， Trunk 就是將這條馬路拓寬為三線道四線道，白話點的解釋可以這樣想像。         而當大家遇到這些問題的時候各家廠商就會去各自提出解決的方式。在過去， INTEL 叫 LINK AGGREGATION ， CISCO 叫 FAST ETHERCHANNEL ， 3C OM 叫 PORT TRUNKING 。百家爭鳴的結果所以衍生一個國際標準： IEEE 802.3a d LACP         但 Trunking 為 static 的，沒有設定就不會有這功能。 LACP 則差別是有 Learning 的概念，透過一段時間後可以找出最適合現在網路狀況的...

摘自:  http://www.ipsec-howto.org/x202.html ,   https://technet.microsoft.com/library/bb878090 https://technet.microsoft.com/en-us/library/cc959510.aspx H3C IPSec :  http://www.h3c.com/cn/Service/Document_Center/Routers/Catalog/ER/ER3100/Configure/Typical_Configuration_Example/H3C_SMB_Router_IPSec_VPN_CG(V1.02)/ What is IPsec? IPsec is an extension to the IP protocol which provides security to the IP and the upper-layer protocols. It was first developed for the new IPv6 standard and then “backported” to IPv4. The IPsec architecture is described in the RFC2401. The following few paragraphs will give you a short introduction into IPsec.     IPsec uses two different protocols - AH and ESP - to ensure the authentication, integrity and confidentiality of the communication. It can protect either the entire IP datagram or only the upper-layer protocols. The appropiate modes are called tunnel mode and transport mode. In tunnel mode the IP datagram is fully enc...

摘自: https://technet.microsoft.com/en-us/library/dd183602(v=ws.10).aspx DHCP lease process A DHCP-enabled client obtains a lease for an IP address from a DHCP server. Before the lease expires, the DHCP client must renew the lease or obtain a new lease. Leases are retained in the DHCP server database for a period of time after expiration. By default, this grace period is four hours and cleanup occurs once an hour for a DHCP server running Windows Server 2008. This protects a client’s lease in case the client and server are in different time zones, the internal clocks of the client and server computers are not synchronized, or the client is off the network when the lease expires. Obtaining a new lease A DHCP client initiates a conversation with a DHCP server when it is seeking a new lease, renewing a lease, rebinding, or restarting. The DHCP conversation consists of a series of DHCP messages passed between the DHCP client and DHCP servers. The following figure shows an ov...