|
|
Troubleshooting provides information about how to avoid having problems with your Cisco 675e product. There are some known problems listed here as well as some ways to fix some of them.
This chapter documents general product known issues in the Cisco 675e product line. Please refer to the Cisco 675e release notes document for a current list of product features available in the Cisco 675e you purchased.
At this time, this chapter is a collection of known issues that could cause problems.
If the WAN-LNK LED does not appear "On" when you power up the modem, wait for 15 seconds. If after 15 seconds it does not appear on, double-check all cabling and connections. If the LED does not turn on at that point, turn the power off and then on again. If the LED still does not light, call your service representative. Should the PWR/ALARM LED appear RED, turn the power off and then on again. If the LED still appears RED, call your service representative.
Web interface passwords can be from 1 to 7 characters in length.
Internet Explorer 2.0 from Microsoft is incompatible to use as a browser on the Cisco 675e and Cisco 7200 routers. Therefore, Netscape 3.01 or higher or Internet Explorer 3.01 or higher are recommended for use as browsers for the Cisco Web Management Interface.
When using the serial port as your terminal connection, large amounts of serial data may overflow the serial buffer. This results in ASCII garbage appearing to the screen but does not affect performance or operation in any way. To avoid this issue, use Telnet to manage both the Cisco 675e and Cisco 7200.
RADIUS passwords must be less than or equal to 16 characters in length. RADIUS user names may be up to 255 characters in length.
Computers running Linux without the term/termcap database installed will have trouble connecting to Cisco equipment. The message BAD ADDRESS is sometimes displayed as an error message. Install the term/termcap database from the Linux installation media.
If you update IP addresses on many Cisco 675e modems in rapid succession using a Windows 95 PC, the PCs ARP cache may not clear right away. This causes communication problems with subsequent Cisco 675e modems in the line. To clear the PC cache, use the following command at the MS-DOS prompt on your PC:
c:\> arp -d 192.168.0.100
This deletes the MAC address and causes IP to ARP again at IP address 192.168.0.100. The ARP utility comes with Windows 95 and WindowsNT, so if you don't have it in your current installation, you can install it from your original Win95 or WinNT install disks/CD.
On a busy network with many RIP broadcasts and requests, RIP traffic alone can cause the Cisco 675e to remain sufficiently active to not trigger the idle timeout. It is recommended that RIP be disabled if Cisco 675e idle timeouts are used.
The set interface wan0 command supports several other parameters having to do with line rates and training, as shown below.
This section describes BERT tests using a Cisco 6100, Cisco 675e units, and an optional HP Broadband test set.
All tests are based on the single cell version of S-PRBS9. This is the only PRBS pattern that is supported by the HP for generating multiple channels of cell load. All cells will have the same data, therefore it is necessary to have a cell sequence number to verify cell loss. This is done using AAL1.
Cells are generated by the HP and terminated by the Cisco 675e modems in the downstream direction, and vice versa for the upstream direction. The HP can only check BERT data on one channel at a time. It is therefore necessary to manually walk through every channel to verify data integrity. The BERT test can be performed without the HP test set if the Cisco 6100 NIU is physically looped back at the OC3 port.
The following are the procedures for transmitting BERT data. Note that all pertinent tests will be initiated from the Optical Line Interface Card, and not a Cell Processor.
Once the Cisco 675e has been BERT-enabled, it sends S-PRBS9 BERT data to the Cisco 6100. The HP can verify the BERT data once channel at a time. The following are the procedures for receiving BERT data. Note you must use the ViewRunner to set up all connections to the HP (see above).
This will give you the statistics for the cell that is currently selected in the receive filter. Repeat the above procedure to check other channels. The Cell Protocol Processors can be used to view incoming cells if desired.
See the following procedures for configuring the Cisco 675e:
1. Login to the Cisco 675e via Ethernet or serial port.
2. Give access to the BERT commands: cbos> enable debug commands <Enter>
3. Keep the Cisco 675e from trying to re-train even though it does not recognize a Cisco 7200 on the other end of the network connection: cbos# ifconfig wan0 stay <Enter>
4. Initiate the BERT test: cbos# debug bert on <Enter>
5. Set the header bits of the outgoing cells and qualify the incoming cells.
6. Then do: cbos# debug bert header 00100010 <Enter>
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|
|
| GFC |
|
|
| VPI |
|
|
| VPI |
|
|
| VCI |
|
|
| VCI |
|
|
| VCI |
|
|
| VCI |
|
| PTI |
| CLP |
7. Display a count of the BERT errors and cell loss since the previous query:cbos# debug bert count <Enter>
1. If the WAN LNK LED blinks continuously and never stays solid on, the Cisco 675e never trains with the Cisco 6100 series. There are a number of reasons why this would occur:
2. If the Cisco 675e trains up and the WAN LNK LED turns off after approximately 1:45 (105 seconds) when the Cisco 675e is in routing mode, this means that the Cisco 675e is not getting the PPP requests answered by the router on the service provider's network, such as the Cisco 7200. It takes 105 seconds for three PPP requests to be sent from the Cisco 675e, and if they are not answered by the Cisco 7200, the Cisco 675e stops sending them and the WAN LNK LED turns off. There are a number of possibilities why this would happen:
3. If the WAN LNK LED turns off after the Cisco 675e has successfully been transferring data end-to-end for some time, this means that the Cisco 675e or the Cisco 7200 might have a timeout set. There are 2 timeouts that could affect the WAN LNK LED:
4. If the WAN LNK LED goes solid for approximately four seconds and then turns off, this primarily points to a RADIUS problem. After the Cisco 675e trains and the Cisco 7200 that is being used to authenticate its PPP session is using RADIUS, then this could point to a failed RADIUS authentication. Possible reasons for a failed RADIUS authentication:
Posted: Thu May 27 13:14:40 PDT 1999
Copyright 1989-1999©Cisco Systems Inc.