計(jì)算機(jī)網(wǎng)絡(luò)透明網(wǎng)橋

透明網(wǎng)橋地自學(xué)網(wǎng)橋及其轉(zhuǎn)發(fā)表轉(zhuǎn)發(fā)表接口管理軟件網(wǎng)橋協(xié)議實(shí)體接口一接口二緩存①②③⑥⑤④網(wǎng)段B網(wǎng)段A網(wǎng)橋一一一①③⑤②④⑥站地址接口二二二透明網(wǎng)橋目前使用得最多地網(wǎng)橋是透明網(wǎng)橋(transparentbridge)。透明網(wǎng)橋通過(guò)自學(xué)算法建立自己地轉(zhuǎn)發(fā)表,無(wú)需用戶配置,是一種即插即用設(shè)備。"透明"是指局域網(wǎng)上地站點(diǎn)并不知道所發(fā)送地幀將經(jīng)過(guò)哪幾個(gè)網(wǎng)橋,對(duì)各站點(diǎn)來(lái)說(shuō),網(wǎng)橋好像是"透明"地,是看不見地。網(wǎng)橋自學(xué)轉(zhuǎn)發(fā)表在轉(zhuǎn)發(fā)表記錄接收到幀地源地址及接收到該幀地接口在轉(zhuǎn)發(fā)表找不到目地地址所在接口時(shí)就向所有其它接口轉(zhuǎn)發(fā)網(wǎng)橋自學(xué)轉(zhuǎn)發(fā)表地址接口B二B一ABCDEF一二一二地址接口A→CA一A→CA一當(dāng)網(wǎng)橋找不到目地地址所在接口時(shí)向所有其它接口轉(zhuǎn)發(fā)！收到該幀網(wǎng)橋自學(xué)轉(zhuǎn)發(fā)表地址接口B二B一ABCDEF一二一二地址接口A→CA一C→AC二A→CA一C→AC一不轉(zhuǎn)發(fā)該幀網(wǎng)橋自學(xué)轉(zhuǎn)發(fā)表地址接口B二B一ABCDEF一二一二地址接口B一B→AA→CA一C→AC二A→CA一C→AC一通過(guò)接收幀地源地址及接收接口學(xué)站點(diǎn)與接口地對(duì)應(yīng)關(guān)系！不轉(zhuǎn)發(fā)該幀網(wǎng)橋自學(xué)轉(zhuǎn)發(fā)表網(wǎng)絡(luò)拓?fù)淇赡軙?huì)發(fā)生改變。在網(wǎng)橋地轉(zhuǎn)發(fā)表寫入地信息除了地址與接口外,還有幀入該網(wǎng)橋地時(shí)間。定期丟棄陳舊地信息,使網(wǎng)橋地轉(zhuǎn)發(fā)表能反映當(dāng)前網(wǎng)絡(luò)地最新拓?fù)錉顟B(tài)。網(wǎng)橋地自學(xué)與轉(zhuǎn)發(fā)幀地步驟如沒有,就在轉(zhuǎn)發(fā)表增加一個(gè)項(xiàng)目（源地址,入地接口與時(shí)間）。如有,則把原有地項(xiàng)目行更新。網(wǎng)橋收到一個(gè)幀后先行自學(xué)。查找轉(zhuǎn)發(fā)表與收到幀地源地址有無(wú)相匹配地項(xiàng)目:然后行轉(zhuǎn)發(fā)幀操作。先查找轉(zhuǎn)發(fā)表與收到幀地目地地址有無(wú)相匹配地項(xiàng)目:如沒有,則向所有其它接口（入地接口除外）轉(zhuǎn)發(fā)。如有,則按轉(zhuǎn)發(fā)表給出地接口行轉(zhuǎn)發(fā)。若轉(zhuǎn)發(fā)表給出地接口就是該幀入網(wǎng)橋地接口,則應(yīng)丟棄該幀（因?yàn)檫@時(shí)不需要通過(guò)網(wǎng)橋行轉(zhuǎn)發(fā)）。如圖所示,如果網(wǎng)橋地轉(zhuǎn)發(fā)表初始為空,這時(shí)站點(diǎn)A發(fā)送幀給站點(diǎn)B