广域网 : X.25 协议

X.25 背对背连接

2016 年 10 月 24 日 - 机器翻译
其他版本: PDFpdf | 英语 (2015 年 8 月 22 日) | 反馈


目录


简介

本文为X.25背对背连接提供一配置示例。您可以用它来验证您的连接和硬件是否适当运行。

先决条件

要求

本文读者应该有基本的了解的下列:

  • X.25

  • TCP/IP

使用的组件

本文档中的信息基于以下软件和硬件版本。

  • 此配置是可适用的对所有思科IOSï ¿  ½软件版本。所有路由器(Cisco 2500路由器)本文使用Cisco IOS软件版本12.2(10b)的。

  • X.25连接的DCE端用广域网DCE电缆连接。

  • X.25连接的DTE端用广域网DTE电缆连接。

关于广域网DCE和DTE电缆的更多信息,参考串行电缆

本文档中的信息都是基于特定实验室环境中的设备编写的。本文档中使用的所有设备最初均采用原始(默认)配置。如果您使用的是真实网络,请确保您已经了解所有命令的潜在影响。

规则

有关文档规则的详细信息,请参阅 Cisco 技术提示规则

配置

在此部分,您提交以信息配置在本文描述的方案。

注意: 要查找本文档所用命令的其他信息,请使用命令查找工具仅限注册用户)。

网络图

本文档使用下图所示的网络设置。

/image/gif/paws/7921/x25_back1.gif

默认串行封装是思科高级数据链路控制(HDLC)。使用encapsulation x25命令,您必须明确配置X.25封装方法。dce选项指定操作作为逻辑X.25 DCE设备。

在背对背串行连接,有电缆的DCE末端的路由器作为物理层DCE并且为线路提供时钟信号。clock rate命令在接口配置模式使路由器在电缆(Prasit的DCE末端,在本例中)提供时钟信号给线路。

注意: 以上任何一个两路由器能作为逻辑X.25 DCE设备,电缆末端连接到路由器。换句话说, encapsulation x25 dce命令在二者之一可以安置上述两路由器之一。

配置

本文使用如下所示的配置。在此配置中, Prasit作为物理层和X.25 DCE,并且Spicey是物理层和X.25 DTE。

Prasit
interface Serial0
  ip address 5.0.2.1 255.255.255.0
  encapsulation x25 dce

!--- Specifies a serial interface's 
!--- operation as an X.25 DCE device. 

  x25 address 7890

!--- Sets the X.121 address. 

  x25 map ip 5.0.2.2 1234

!--- Sets up the LAN protocols-to-remote 
!--- host mapping. 

  clockrate 64000

!--- Specifies a serial interface's operation 
!--- as a physical layer DCE device. 

  no cdp enable

Spicey
interface Serial1
  ip address 5.0.2.2 255.255.255.0
  encapsulation x25

!--- Specifies a serial interface's operation 
!--- as an X.25 device. Default X.25 
!--- encapsulation mode is "dte".

  x25 address 1234
  x25 map ip 5.0.2.1 7890
  no cdp enable

验证

本部分所提供的信息可用于确认您的配置是否正常工作。

命令输出解释程序工具仅限注册用户)支持某些 show 命令,使用此工具可以查看对 show 命令输出的分析。

  • show controllers serial —显示关于接口硬件和连接的电缆的信息。欲了解更详细的信息参考命令参考

  • ping —检查主机可接通性和网络连通性。欲了解更详细的信息参考命令参考

  • show x25 vc —显示关于X.25 SVC和PVC的信息。欲了解更详细的信息参考命令参考

  • show interfaces serial —显示关于接口特性的信息,例如封装、带宽和其他详细信息。欲了解更详细的信息参考命令参考

如下所示的输出是输入这些on命令结果设备在此配置示例方面。

请使用show controllers命令检查Prasit是物理层DCE和Spicey是物理层DTE。此命令提供您信息物理层是否工作,并且什么类型的电缆连接。

prasit# show controllers serial 0
HD unit 0, idb = 0x1D3A2C, driver structure at 0x1DAFE8
buffer size 1524 HD unit 0, V.35 DCE cable, clockrate 64000

!---Output suppressed.

spicey# show controllers serial 1
HD unit 1, idb = 0x153E94, driver structure at 0x15A1F8
buffer size 1524 HD unit 1, V.35 DTE cable

!---Output suppressed.

要验证X.25背对背配置,请使用以下步骤。

  1. 从X.25 DCE ping (在本例中, Prasit)对X.25 DTE (Spicey)。

    默认情况下在这种情况下,使用SVC1,配置的最低一个。

    prasit# ping 5.0.2.2
    
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 5.0.2.2, timeout is 2 seconds:
    !!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 36/38/48 ms
    
    prasit# show x25 vc
    SVC 1,  State: D1,  Interface: Serial0
      Started 00:00:07, last input 00:00:07, output 00:00:07
      Connects 1234 <-> ip 5.0.2.2
      Call PID cisco, Data PID none
      Window size input: 2, output: 2
      Packet size input: 128, output: 128
      PS: 5  PR: 5  ACK: 4  Remote PR: 5  RCNT: 1  RNR: no
      P/D state timeouts: 0  timer (secs): 0
      data bytes 500/500 packets 5/5 Resets 0/0 RNRs 0/0 REJs 0/0 INTs 0/0
    
    prasit# show interfaces serial 0
    Serial0 is up, line protocol is up
      Hardware is HD64570
      Internet address is 5.0.2.1/24
      MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, 
         reliability 255/255, txload 1/255, rxload 1/255
      Encapsulation X25, loopback not set
      X.25 DCE, address 7890, state R1, modulo 8, timer 0
          Defaults: idle VC timeout 0
            cisco encapsulation
            input/output window sizes 2/2, packet sizes 128/128
          Timers: T10 60, T11 180, T12 60, T13 60
          Channels: Incoming-only none, Two-way 1-1024, Outgoing-only none
          RESTARTs 1/0 CALLs 2+0/0+0/0+0 DIAGs 0/0
      LAPB DCE, state CONNECT, modulo 8, k 7, N1 12056, N2 20
          T1 3000, T2 0, interface outage (partial T3) 0, T4 0
          VS 5, VR 5, tx NR 5, Remote VR 5, Retransmissions 0
          Queues: U/S frames 0, I frames 0, unack. 0, reTx 0
          IFRAMEs 29/29 RNRs 0/0 REJs 0/0 SABM/Es 0/1 FRMRs 0/0 DISCs 0/0
      Last input 00:00:13, output 00:00:13, output hang never
      Last clearing of "show interface" counters 00:22:38
      Queueing strategy: fifo
      Output queue 0/40, 0 drops; input queue 0/75, 0 drops
      5 minute input rate 0 bits/sec, 0 packets/sec
      5 minute output rate 0 bits/sec, 0 packets/sec
         33 packets input, 2679 bytes, 0 no buffer
         Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
         0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
         42 packets output, 2693 bytes, 0 underruns
         0 output errors, 0 collisions, 0 interface resets
         0 output buffer failures, 0 output buffers swapped out
         0 carrier transitions
         DCD=up  DSR=up  DTR=up  RTS=up  CTS=up
    prasit#
  2. 然后请从X.25 DTE (Spicey) ping对X.25 DCE (Prasit)。

    spicey# ping 5.0.2.1
    
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 5.0.2.1, timeout is 2 seconds:
    !!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 32/32/36 ms
    spicey#
    
    spicey# show x25 vc
    SVC 1,  State: D1,  Interface: Serial1
      Started 00:01:03, last input 00:01:03, output 00:01:03
      Connects 7890 <-> ip 5.0.2.1
      Call PID ietf, Data PID none
      Window size input: 2, output: 2
      Packet size input: 128, output: 128
      PS: 5  PR: 5  ACK: 5  Remote PR: 4  RCNT: 0  RNR: no
      P/D state timeouts: 0  timer (secs): 0
      data bytes 500/500 packets 5/5 Resets 0/0 RNRs 0/0 REJs 0/0 INTs 0/0
    
    spicey# show interfaces serial 1
    Serial1 is up, line protocol is up
      Hardware is HD64570
      Internet address is 5.0.2.2/24
      MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, 
         reliability 255/255, txload 1/255, rxload 1/255
      Encapsulation X25, loopback not set
      X.25 DTE, address 1234, state R1, modulo 8, timer 0
          Defaults: idle VC timeout 0
            cisco encapsulation
            input/output window sizes 2/2, packet sizes 128/128
          Timers: T20 180, T21 200, T22 180, T23 180
          Channels: Incoming-only none, Two-way 1-1024, Outgoing-only none
          RESTARTs 1/1 CALLs 0+0/2+0/0+0 DIAGs 0/0
      LAPB DTE, state CONNECT, modulo 8, k 7, N1 12056, N2 20
          T1 3000, T2 0, interface outage (partial T3) 0, T4 0
          VS 5, VR 5, tx NR 5, Remote VR 5, Retransmissions 0
          Queues: U/S frames 0, I frames 0, unack. 0, reTx 0
          IFRAMEs 29/29 RNRs 0/0 REJs 0/0 SABM/Es 1/0 FRMRs 0/0 DISCs 0/0
      Last input 00:01:10, output 00:01:10, output hang never
      Last clearing of "show interface" counters 00:23:59
      Queueing strategy: fifo
      Output queue 0/40, 0 drops; input queue 0/75, 0 drops
      5 minute input rate 0 bits/sec, 0 packets/sec
      5 minute output rate 0 bits/sec, 0 packets/sec
         42 packets input, 2693 bytes, 0 no buffer
         Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
         0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
         32 packets output, 2657 bytes, 0 underruns
         0 output errors, 0 collisions, 0 interface resets
         0 output buffer failures, 0 output buffers swapped out
         2 carrier transitions
         DCD=up  DSR=up  DTR=up  RTS=up  CTS=up
  3. 请使用以下命令清除在Spicey Serial1的X.25连接:

    spicey# clear x25 serial 1
    Force Restart [confirm]
  4. 在清除X.25连接以后,请设法从DTE ping (在本例中, Spicey)到DCE (Prasit)。

    在这种情况下,使用SVC1024 (配置的最高一个)。

    spicey# ping 5.0.2.1
    
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 5.0.2.1, timeout is 2 seconds:
    !!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 32/36/44 ms
    
    spicey# show x25 vc
    SVC 1024,  State: D1,  Interface: Serial1
      Started 00:00:04, last input 00:00:04, output 00:00:04
      Connects 7890 <-> ip 5.0.2.1
      Call PID cisco, Data PID none
      Window size input: 2, output: 2
      Packet size input: 128, output: 128
      PS: 5  PR: 5  ACK: 4  Remote PR: 5  RCNT: 1  RNR: no
      P/D state timeouts: 0  timer (secs): 0
      data bytes 500/500 packets 5/5 Resets 0/0 RNRs 0/0 REJs 0/0 INTs 0/0
  5. 再请使用同样命令在Prasit。

    prasit# ping 5.0.2.2
    
    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 5.0.2.2, timeout is 2 seconds:
    !!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 32/34/36 ms
    
    prasit# show x25 vc
    SVC 1024,  State: D1,  Interface: Serial0
      Started 00:01:34, last input 00:01:34, output 00:01:34
      Connects 1234 <-> ip 5.0.2.2
      Call PID ietf, Data PID none
      Window size input: 2, output: 2
      Packet size input: 128, output: 128
      PS: 5  PR: 5  ACK: 5  Remote PR: 4  RCNT: 0  RNR: no
      P/D state timeouts: 0  timer (secs): 0
      data bytes 500/500 packets 5/5 Resets 0/0 RNRs 0/0 REJs 0/0 INTs 0/0

故障排除

目前没有针对此配置的故障排除信息。


相关信息


Document ID: 7921