【導(dǎo)讀】網(wǎng)絡(luò)的拓撲是這樣的：一根入線先連一個交換機，現(xiàn)在需要配置路由器：。，一端連虛擬終端的串行口，一端連路由器的Console口.，出現(xiàn)#####。。。。。企業(yè)網(wǎng)絡(luò)建設(shè)規(guī)劃中不可缺少的一部分。本文以Cisco2620為例，講述了路由器的初始化配。分配地址信息以及路由器常見故障的排除技巧。鍵入configterminal，出現(xiàn)提示符Cisco2620#，進入配置模式。Cisco2620#password123123：設(shè)置Console口密碼為123123. Cisco2620#encapsulationppp:把數(shù)據(jù)鏈路層協(xié)議設(shè)為PPP. Cisco2620#iptcpheader-pressionpassive：啟用被動IP包頭壓縮。撥號聯(lián)入局域網(wǎng)、登錄服務(wù)器，實現(xiàn)遠程辦公。通過防火墻訪問Inter。

　　

【正文】 ip address framereply interfacedlci 105 ! interface serial pointtopoint ip address framereply interfacedlci 102 ! interface serial pointtopoint ip address framereply interfacedlci 104 ! Router2: interface serial 0 encapsulation framerelay ! interface serial pointtopoint ip address framereply interfacedlci 201 ! interface serial pointtopoint ip address framereply interfacedlci 203 ! 相關(guān)調(diào)試命令 ： show framerelay lmi show framerelay map show framerelay pvc show framerelay route show interfaces serial go top 4. 幀中繼 Multipoint 配置實例 : Router1: interface serial 0 encapsulation framereply ! interface serial multipoint ip address framereply map ip 201 broadcast framereply map ip 301 broadcast framereply map ip 401 broadcast ! Router2: interface serial 0 encapsulation framereply ! interface serial multipoint ip address framereply map ip 102 broadcast framereply map ip 102 broadcast framereply map ip 102 broadcast ! 五、 ISDN 1. 綜合數(shù)字業(yè)務(wù)網(wǎng)（ ISDN） 綜合數(shù)字業(yè)務(wù)網(wǎng)（ ISDN）由數(shù)字電話和數(shù)據(jù)傳輸服務(wù)兩部分組成，一般由電話局提供這種服務(wù)。 ISDN的基本速率接口（ BRI）服務(wù)提供 2 個 B 信道和 1 個 D 信道（ 2B+D）。 BRI的 B 信道速率為 64Kbps,用于傳輸用戶數(shù)據(jù)。 D 信道的速率為 16Kbps，主要傳輸控制信號。在北美和日本，ISDN的主速率接口（ PRI）提供 23個 B 信道和 1 個 D 信道，總速率可達 ，其中 D 信道速率為 64Kbps。而在歐洲、澳大利亞等國家， ISDN的 PRI提供 30個 B 信道和 1 個 64Kbps D 信道，總速率可達 。我國電話局所提供 ISDN PRI 為 30B+D。 2. 基本命令 任務(wù) 命令 設(shè)置 ISDN交換類型 isdn switchtype switchtype1 接口設(shè)置 interface bri 0 設(shè)置 PPP封裝 encapsulation ppp 設(shè)置協(xié)議地址與電話號碼的映射 dialer map protocol nexthopaddress [name hostname] [broadcast] [dialstring] 啟動 PPP多連接 ppp multilink 設(shè)置啟動另一個 B 通道的閾值 dialer loadthreshold load 顯示 ISDN有關(guān)信息 show isdn {active | history | memory | services | status [dsl | interfacetype number] | timers} 注： ,國內(nèi)交換機一般為 basic3。 按區(qū)域分關(guān)鍵字 交換機類型 Australia basicts013 Australian TS013 switches Europe basic1tr6 German 1TR6 ISDN switches basicnw3 Norway NET3 switches (phase 1) basic3 NET3 ISDN switches (UK, Denmark, and other nations)。 covers the EuroISDN EDSS1 signalling system primary5 NET5 switches (UK and Europe) vn2 French VN2 ISDN switches vn3 French VN3 ISDN switches Japan ntt Japanese NTT ISDN switches primaryntt Japanese ISDN PRI switches North America basic5ess ATamp。T basic rate switches basicdms100 NT DMS100 basic rate switches basicni1 National ISDN1 switches primary4ess ATamp。T 4ESS switch type for the . (ISDN PRI only) primary5ess ATamp。T 5ESS switch type for the . (ISDN PRI only) primarydms100 NT DMS100 switch type for the . (ISDN PRI only) New Zealand basicnz3 New Zealand Net3 switches 3. ISDN實現(xiàn) DDR（ dialondemand routing）實例 : 設(shè)置如下： Router1: hostname router1 user router2 password cisco ! isdn switchtype basic3 ! interface bri 0 ip address encapsulation ppp dialer map ip name router2 572 dialer loadthreshold 80 ppp multilink dialergroup 1 ppp authentication chap ！ dialerlist 1 protocol ip permit ! Router2: hostname router2 user router1 password cisco ! isdn switchtype basic3 ! interface bri 0 ip address encapsulation ppp dialer map ip name router1 571 dialer loadthreshold 80 ppp multilink dialergroup 1 ppp authentication chap ！ dialerlist 1 protocol ip permit ! Cisco路由器同時支持回撥功能，我們將路由器 Router1作為 Callback Server,Router2 作為Callback Client。 與回撥相關(guān)命令 : 任務(wù) 命令 映射協(xié)議地址和電話號碼，并在接口上使用在全局模式下定義的 PPP回撥的映射類別。 dialer map protocol address name hostname class classname dialstring 設(shè)置接口支持 PPP回撥 ppp callback accept 在全局模式下為 PPP回撥設(shè)置映射類別 mapclass dialer classname 通過查找注冊在 dialer map里的主機名來決定回撥 . dialer callbackserver [username] 設(shè)置接口要求 PPP回撥 ppp callback request 設(shè)置如下： Router1: hostname router1 user router2 password cisco ! isdn switchtype basic3 ! interface bri 0 ip address encapsulation ppp dialer map ip name router2 class s3 572 dialer loadthreshold 80 ppp callback accept ppp multilink dialergroup 1 ppp authentication chap ！ mapclass dialer s3 dialer callbackserver username dialerlist 1 protocol ip permit ! Router2: hostname router2 user router1 password cisco ! isdn switchtype basic3 ! interface bri 0 ip address encapsulation ppp dialer map ip name router1 571 dialer loadthreshold 80 ppp callback request ppp multilink dialergroup 1 ppp authentication chap ！ dialerlist 1 protocol ip permit ! 相關(guān)調(diào)試命令 ： debug dialer debug isdn event debug isdn q921 debug isdn q931 debug ppp authentication debug ppp error debug ppp negotiation debug ppp packet show dialer show isdn status 舉例 :執(zhí)行 debug dialer命令觀察 router2呼叫 router1,router1回撥 router2的過程 . router1debug dialer router2ping router1 00:03:50: %LINK3UPDOWN: Interface BRI0:1, changed state to up 00:03:50: BRI0:1:PPP callback Callback server starting to router2 572 00:03:50: BRI0:1: disconnecting call 00:03:50: %LINK3UPDOWN: Interface BRI0:1, changed state to down 00:03:50: BRI0:1: disconnecting call 00:03:50: BRI0:1: disconnecting call 00:03:51: %LINK3UPDOWN: Interface BRI0:2, changed state to up 00:03:52: callback to router2 already started 00:03:52: BRI0:2: disconnecting call 00:03:52: %LINK3UPDOWN: Interface BRI0:2, changed state to down 00:03:52: BRI0:2: disconnecting call 00:03:52: BRI0:2: disconnecting call 00:04:05: : Callback timer expired 00:04:05: BRI0:beginning callback to router2 572 00:04:05: BRI0: Attempting to dial 572 00:04:05: Freeing callback to router2 572 00:04:05: %LINK3UPDOWN: Interface BRI0:1, changed state to up 00:04:05: BRI0:1: No callback negotiated 00:04:05: %LINK3UPDOWN: Interface VirtualAccess1, changed state to up 00:04:05: dialer Protocol up for Vi1 00:04:06: %LINEPROTO5UPDOWN: Line