1、CCNP TShoot排錯 v2.0 (300-135)串行鏈路TShooting資深培訓講師：黑眼學習交流：189 605 661CCNP TShoot排錯 v2.0 (300-135)第 2 層故障排除 - PPPPPP協商流程LCP up底層 upAuthenticate 階段Dead 階段Establish 階段驗證通過或無驗證驗證失敗失敗downTerminate 階段Network 階段關閉第 2 層故障排除 - PPP步驟 1. 利用 show裝均正確。erfaserial 命令檢查兩端所使用的封S0/0/0S0/0/0PPPCSU/DSU問題：R6的封裝錯誤配置為HDLCCSU

2、/DSUR6#showerfas0/1Serial0/1 is up, line protocol is downHardware is M4Ternet address is 16.16.16.6/24MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,reliability 255/255, txload 1/255, rxload 1/255Encapsulation HDLC, crc 16, loack not set第 2 層故障排除 - PPP步驟 2. 通過檢查輸出中有無 LCP Open 消息來確認鏈路控制協議 (LCP) 協商是否成功。

3、S0/0/0S0/0/0PPPCSU/DSUCSU/DSUR6封裝更正為PPP，LCP OPEN表示LCP協商已成功R6#showerfa0/1Serial0/1 is up, line protocol is upHardware is M4Ternet address is 16.16.16.6/24MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255Encapsulation PPP, LCP Open第 2 層故障排除 - PPP步驟 3. 利用 deb

4、ug ppp authentication 命令檢驗鏈路兩端的驗證。S0/0/0S0/0/0PPPCSU/DSUCSU/DSU驗證？R1 上沒有配置R1#驗證*Mar*Mar*Mar*Mar1 01:50:15.591: Se0/1 PPP: Authorization required1 01:50:15.667: Se0/1 PPP: No authorization without authentication 1 01:50:15.695: Se0/1 CHAP: I CHALLENGE id 14 len 23 from R61 01:50:15.703: Se0/1 CHAP: U

5、nable to authenticate for peerPAP 驗證PAP是兩次握手驗證協議，口令以明文傳送，被驗證方首先發起驗證請求。被驗證方主驗證方用戶名R6R1通過 /R1：上的：接口 ：ppp pap sent-username R1 password aaaaaR6（對端）Username R1 password aaaaa接口：ppp authention papCHAP 驗證被驗證方主驗證方主機名(R6)隨機報文R1R6主機名(R1)加密后報文通過 /CHAP是三次握手驗證協議，不發送口令，主驗證方首先發起驗證請求，安全性比PAP高。CCNP TShoot排錯 v2.0 (3

6、00-135)第 2 層故障排除 - 幀中繼第 2 層故障排除 - 幀中繼步驟 1. 檢驗 CSU/DSU （數據服務單元）與路由器之間的物理連接。S0/0/0S0/0/0幀中繼提供商CSU/DSUCSU/DSU第 2 層故障排除 - 幀中繼步驟 2. 利用 showerfaserial 命令檢驗兩臺路由器所使用的幀中繼封裝是否匹配。S0/0/0S0/0/0幀中繼提供商CSU/DSU0/0CSU/DSUR2#sherfaernet address is 26.26.26.2/24MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, reliability

7、255/255, txload 1/255, rxload 1/255Encapsulation FRAME-RELAY, crc 16, loack not setR6#shs0/0ernet address is 26.26.26.6/24MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255Encapsulation FRAME-RELAY, crc 16, loack not set第 2 層故障排除 - 幀中繼步驟 3. 利用 shows0/0/0命令檢

8、驗路由器與幀中繼提供商是否能夠正確地交換 LMI 信息。S0/0/0S0/0/0幀中繼提供商CSU/DSUR6#shs0/0/0CSU/DSUSerial0/0/0 is up, line protocol is downernet address is 26.26.26.6/24MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255Encapsulation FRAME-RELAY, crc 16, lo Keepalive set (10 sec)Restar

9、t-Delay is 0 secsack not setLMI enq sent 5, LMI s LMI enq recvd 0, LMI srecvd 0, LMI upd recvd 0, D sent 0, LMI upd sent 0MI downLMI DLCI 1023 LMI type is CISCO frame relay DTE狀態請求數=收到的狀態消息數第 2 層故障排除 - 幀中繼步驟 4. 利用 show frame-relay map 命令檢驗 PVC 是否處于活動狀態。S0/0/0S0/0/0幀中繼提供商CSU/DSUCSU/DSUR2(config-if)#d

10、o show frame-relay maps0/0/0(up):ip 1.1.1.1 dlci 100(0 x64,0 x1840),dynamic,broadcast,s顯示動態LMI建立的，pvc的狀態有三種us defined, activeACTIVE 說明Inactive狀態虛電路已經建立：兩個節點之間的幀中繼鏈路已經建立； 幀中繼提供商已提供對應于DLCI號,但未被路由器使用,通常的錯誤是兩個幀中繼之間的DLCI號反了；Deleted狀態路由器配置DLCI號未被幀中繼提供商提供,因此,PVC不能被建立,有可能幀中繼提供商未激活PVC。CCNP TShoot排錯 v2.0 (300-135)第 2 層故障排除 案例串行鏈路Loack03.3.3.3/32Loack06.6.6.6/32Loack030.30.30.3/241.1.1.1/32FRPPPchapS0/116.16.16.1/24R1S0/1 16.16.16.6/2420.20.20.2/24Loack0 2.2.2.2/3210.10