【正文】 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。 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 PP 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 protocol on Interface BRI0:1, changed state to up 00:04:06: %LINEPROTO5UPDOWN: Line protocol on Interface VirtualAccess1, chang ed state to up 00:04:11: %ISDN6CONNECT: Interface BRI0:1 is now connected to 572 router1 4. ISDN 訪問首都在線 263 網(wǎng)實例 : 本地局部網(wǎng)地址為 ,屬于保留地址，通過 NAT 地址翻譯功能，局域網(wǎng)用戶可以通過 ISDN 上 263網(wǎng)訪問 Inter。 set system c765 c765 set multidestination on c765 set switch 3 c765 set ppp multilink on c765 cd lan c765:LAN set ip routing on c765:LAN set ip address c765:LAN set ip mask c765:LAN set briding off c765:LANcd c765 set user remote New user remote being created c765:remote set ip routing on c765:remote set bridging off c765:remote set ip framing none c765:remote set ppp clientname 263 c765:remote set ppp password client Enter new Password: 263 ReType new Password: 263 c765:remote set ppp authentication out none c765:remote set ip address c765:remote set ip mask c765:remote set ppp address negotiation local on c765:remote set ip pat on c765:remote set ip route destination c765:remote set number 2633 c765:remote set active 命令描述如下： 任務(wù) 命令 設(shè)置路由器系統(tǒng)名稱 set system c765 允許路由器呼叫多個目的地 set multidestination on 設(shè)置 ISDN 交換機類型為 NET3 set switch 3 允許點到點間多條通道連接實現(xiàn)負載均衡 set ppp multilink on 關(guān)掉橋接 set briding off 建立用戶預制文件用于設(shè)置撥號連接參數(shù) 可以設(shè)置多個用戶預制文件用于相同 的物理端口對應于不同的連接。電話網(wǎng)絡(luò)的應用一般可分為兩種類型，一種是同等級別機構(gòu)之間以按需撥號(DDR)的方式實現(xiàn)互連，一種是 ISP 為撥號上網(wǎng)為用戶提供的遠程訪問服務(wù)的功能。 全局設(shè)置： 任務(wù) 命令 設(shè)置用戶名和密碼 username username password password 設(shè)置用戶的 IP 地址池 ip local pool {default | poolname lowipaddress [highipaddress]} 指定地址池的工作方式 ip addresspool [dhcpproxyclient | local] 基本接口設(shè)置命令： 任務(wù) 命令 設(shè)置封裝形式為 PPP encapsulation ppp 啟動異步口的路由功能 async default routing 設(shè)置異步口的 PPP 工作方式 async mode {dedicated | interactive} 設(shè)置用戶的 IP 地址 peer default ip address {ipaddress | dhcp | pool [poolname]} 設(shè)置 IP 地址與 Ether0 相同 ip unnumbered ether0 line 撥號線設(shè)置： 任務(wù) 命令 設(shè)置 modem 的工作方式 modem {inout|dialin} 自動配置 modem 類型 modem autoconfig discovery 設(shè)置撥號線的通訊速率 speed speed 設(shè)置通訊線路的流控方式 flowcontrol {none | software [lock] [in | out] | hardware [in | out]} 連通后自動執(zhí)行命令 automand mand 訪問服務(wù)器設(shè)置如下： Router: hostname Router enable secret 5 $1$EFqU$tYLJLrynNUKzE4bx6fmH// ! interface Ether0 ip address ! interface Async1 ip unnumbered Ether0 encapsulation ppp keepalive 10 async mode interactive peer default ip address pool Cisco2511Group142 ! ip local pool Cisco2511Group142 ! line con 0 exectimeout 0 0 password cisco ! line 1 16 modem InOut modem autoconfigure discovery flowcontrol hardware ! line aux 0 transport input all line vty 0 4 password cisco ! end 相關(guān)調(diào)試命令： show interface show line . Access Server 通過 Tacacs 服務(wù)器實現(xiàn)安全認證： 使用一臺 WINDOWS NT 服務(wù)器作為 Tacacs 服務(wù)器，地址為 ,運行 Cisco2511隨機帶的 Easy ACS 軟件實現(xiàn)用戶認證功能 . 相關(guān)設(shè)置 ： 任務(wù) 命令 激活 AAA 訪問控制 aaa newmodel 用戶登錄時默認起用 Tacacs+做 AAA 認證 aaa authentication login default tacacs+ 列表名為 no_tacacs 使用 ENABLE 口令做認證 aaa authentication login no_tacacs enable 在運行 PPP 的串行線上采用 Tacacs+做認證 aaa authentication ppp default tacacs+ 由 TACACS+服務(wù)器授權(quán)運行 EXEC aaa authorization exec tacacs+ 由 TACACS+服務(wù)器授權(quán)與網(wǎng)絡(luò)相關(guān)的服務(wù)請求。 aaa accounting exec startstop tacacs+ 為與網(wǎng)絡(luò)相關(guān)的服務(wù)需求運行記帳包括 SLIP,PPP,PPP NCPs,ARAP 等 .在進程開始和結(jié)束時發(fā)通告給 TACACS+服務(wù)器。這里使用 tac 作為關(guān)