聯(lián)系人 廈門彬碩-小胡
德國西門子交換機意為“開關”是一種用于電(光)信號轉發(fā)的網(wǎng)絡設備。它可以為接入交換機的任意兩個網(wǎng)絡節(jié)點提供獨享的電信號通路。最常見的交換機是以太網(wǎng)交換機。其他常見的還有電話語音交換機、光纖交換機等。SIEMENS: 3RK 3RA 3RB 3RF 3RG 3RH 3RN 3RP 3RS 3RT 3RV 3RX 3SK 3TC 3TD 3TG 3TH 3TK 3TS 3TX 3UF 3UG 3LD 8WD 6GK 6SE70 6SY 6DD 6RY 6SB 6SL39特價供應
交換機工作于OSI參考模型的第二層,即數(shù)據(jù)鏈路層。交換機內部的CPU會在每個端口成功連接時,通過將MAC地址和端口對應,形成一張MAC表。在今后的通訊中,發(fā)往該MAC地址的數(shù)據(jù)包將僅送往其對應的端口,而不是所有的端口。因此,交換機可用于劃分數(shù)據(jù)鏈路層廣播,即沖突域;但它不能劃分網(wǎng)絡層廣播,即廣播域。[1]
交換機擁有一條很高帶寬的背部總線和內部交換矩陣。交換機的所有的端口都掛接在這條背部總線上,控制電路收到數(shù)據(jù)包以后,處理端口會查找內存中的地址對照表以確定目的MAC(網(wǎng)卡的硬件地址)的NIC(網(wǎng)卡)掛接在哪個端口上,通過內部交換矩陣迅速將數(shù)據(jù)包傳送到目的端口,目的MAC若不存在,廣播到所有的端口,接收端口回應后交換機會“學習”新的MAC地址,并把它添加入內部MAC地址表中。使用交換機也可以把網(wǎng)絡“分段”,通過對照IP地址表,交換機只允許必要的網(wǎng)絡流量通過交換機。通過交換機的過濾和轉發(fā),可以有效的減少沖突域,但它不能劃分網(wǎng)絡層廣播,即廣播域。[1]
端口
6GK5874-3AA00-2FA2
6GK5875-0AA10-1AA2
6GK5896-4MA00-0AA3
6GK5896-4ME00-0AA0
6GK5896-6MH00-0AA0
6GK5904-0PA00
6GK5905-0PA00
6GK5907-0PA00
6GK5907-1SB00
6GK5907-4PA00
6GK5980-1CC00-0AA6
6GK5980-1DB00-0AA5
6GK5980-1DB10-0AA5
6GK5991-1AB00-8AA0
6GK5991-1AC00-8AA0
6GK5991-1AD00-8AA0
6GK5991-4AC00-8AA0
6GK5992-1AG00-8AA0
6GK5992-1AJ00-8AA0
6GK5992-1AK00-8AA0
6GK5992-1AL00-8AA0
6GK5992-1AM00-8AA0
6GK5992-1AM00-8FA0
6GK5992-2AN00-8AA0
6GK5992-2AP00-8AA0
6GK5992-2AQ00-8AA0
6GK5992-2AS00-8AA0
6GK5992-2AS00-8FA0
6GK5992-2GA00-8AA0
6GK5992-4RA00-8AA0
6GK5992-4SA00-8AA0
6GK5993-1AT00-8AA0
6GK5993-1AU00-8AA0
6GK5993-1AV00-8AA0
