Chinaunix首页 | 论坛 | 博客
  • 博客访问: 5600710
  • 博文数量: 745
  • 博客积分: 10075
  • 博客等级: 上将
  • 技术积分: 7716
  • 用 户 组: 普通用户
  • 注册时间: 2005-04-29 12:09
文章分类

全部博文(745)

文章存档

2019年(1)

2016年(1)

2010年(31)

2009年(88)

2008年(129)

2007年(155)

2006年(197)

2005年(143)

分类:

2006-06-25 19:04:07

1,Drag 3 of the ISDN troubleshooting commands from the left, to their matching descriptions on the right:
Show dailer-Determine PAP or CHAP authentication
Debug isdn q921-Display layer 2 access procedures on the D channel
Debug isdn q931-Display call setup and teardown information
 
2,Show frame-relay pvc
The show frame-relay pvc command displays the status of each configured connection as well as traffic statistics. This command is also useful for viewing the number of backward explicit
congestion notification(BECN) and forward explicit congestion notification(FECN) packets received by the router. The PVC STATUS can be active, inactive, or deleted.
Active state-Indicates that the connection is active and that routers can exchange data
Inactive state-Indicates that the local connection to the Frame Relay switch is working, but the remote router's connection to the Frame Relay switch is not working
Deleted state-Indicates that no LMI is being received from the Frame Relay switch, or there is no service between the CPE router and Frame Relay switch
 
3,You're a specialized frame-relay contractor and you've just finished configuring a network.What command would you use to verify the frame-relay traffic-shaping parameters?
answer:show frame-relay pvc
The show frame-relay pvc command displays the status of each configured connection as well as traffic statistics. This command is also useful for viewing the number of backward explicit
congestion notification(BECN) and forward explicit congestion notification(FECN) packets received by the router.
 
4,The possible values of the status of the DLCI are explained below:
  0X0-added/inactive means that the switch has this DLCI programmed but for some reason, it is not usable
  0X2-added/active means the Frame Relay switch has the DLCI and everything is operational. You can start sending it traffic with this DLCI in the header
  0X3-0X3 is a combination of an active status(0X2) and the RNR that is set(0X1)
  0X4-deleted means that the Frame Relay switch doesn't have this DLCI programmed for the router
 
5,While troubleshooting a router issue, you suspect that the CPU may be becoming overutilized.
What command do you use to check the CPU utilization of the router?
answer:show process cpu
Software compression is available in all router platforms. Software compression is performed by the main processor in the router. Compression is performed in software and might significantly
affect system performance. We recommened that you disable compression if the router CPU load exceeds 65 percent. To display the CPU load, use the "show process cpu" EXEC command
 
6,An IPSec tunnel has just been created on the TestKing network, and you wish to verify it.Which command will display the configured IKE policies?
answer:show crypto isakmp policy

7,Frame Relay service provider's use a parameter called committed information rate(CIR) to provision network resources to a Rrame Relay user and regulate usage according to the assigned parameters. A mechanism written for the Frame Relay protocol exists for letting Frame Relay users know that congestion has been encountered within the Rrame Relay network. This mechanism relies on the FECN/BECN bits in the Q.922 header of the frame. The network or the user can selectively set the discard eligible(DE) bit in the frames and drop these frames when congestion is encountered. When the DE bit is set to 1, this means that the frame is Discard Eligible, and that it has exceeded the CIR.
 
8,In a frame relay network, FECN(forward explicit congestion notification) is a header bit transmitted by the source(sending) terminal requesting that the destination(receiving) terminal slow down its requests for data. BECN( backward explicit congestion notification) is a header bit transmitted by the destination terminal requesting that the source terminal send data more slowly.
 
9,Which command displays the reomte network address associated with each PVC?
answer:show frame-relay map
 
10,If you experience trouble with the ADSL connection, make sure to verify the following:
   That the ADSL line is connected and is using pins 3 and 4. For more information on the ADSL connection, see the hardware guide for your router.
   That the ADSL CD LED is on. If it is not on, the router may not be connected to the digital subscriber line access multiplexer(DSLAM). For more information on the ADSL LEDs, see the hardware installation guide specific to your router
   That you are using the correct Asynchronous Transfer Mode(ATM) variable path indentifier and variable circuit identifier(VPI/VCI)
   That the DSLAM supports discrete multi-tone(DMT) Issue 2

 
阅读(1708) | 评论(0) | 转发(0) |
给主人留下些什么吧!~~