Terminal access FAQs

This chapter identifies and explains certain common problems that may occur, and how to solve them.

If an FEP is connected to too many terminals, you must modify the Unix kernel of the FEP to increase stream resources to avoid insufficient stream resources during operation.

You can view system resources utilization by using the ttyd administration program or the following command:

# netstat -m
streams allocation:
            config    alloc     free      total     max    fail
stream          4096     134     3962     10692    135       0
queues          566      271      295     21387    273       0
mblks          2319     445    1874     761868     2149     1
buffer headers  2746   1279    1467      52307     2654     0
class  1,   64 bytes    192    9    183   240804   172      0
class  2,   128 bytes   192    0    192   234865   168      0
class  3,   256 bytes   304    9    295    96179    292     0
class  4,   512 bytes   32    0     32     26368     32     0
class  5,   1024 bytes   32    0     32    2734     29      0
class  6,   2048 bytes   274   182    92     6460   273     0
class  7,   4096 bytes   171    170     1     185   171     0
class  8,   8192 bytes    5     0     5     70      5       0
class  9,  16384 bytes    2      0    2     3     2     0
class 10,  32768 bytes    0     0     0     0      0    0
class 11,  65536 bytes    0      0    0     0      0    0
class 12, 131072 bytes    0     0     0     0      0    0
class 13, 262144 bytes    0     0     0     0      0    0
class 14, 524288 bytes    0     0     0     0      0    0
total configured streams memory: 8000.00KB
streams memory in use: 1103.09KB
maximum streams memory used: 1569.64KB

A value of 1 for the fail column means the system stream resources are insufficient and you must increase stream resources by modifying the Unix server kernel.

You can follow these steps to modify system stream resources (taking SCO OpenServer Unix 5.0x as an example):

1. Log in to the Unix server as a superuser.

2. Enter scoadmin to run SCO OpenServer Unix administration program.

3. Select [Hardware/Kernel Manager] from the main interface to enter the level 2 interface.

4. Select [Tune Parameters…] to enter the level 3 interface.

5. Under the [Configuration tunables] item, Select [12 Streams] to enter the level 4 interface.

6. Set the [NSTRPAGES] field to 2000 (the default is 500).

7. Exit to the level 2 interface and select [Relink Kernel] to recompile the kernel.

8. Exit scoadmin and reboot the Unix server.

After reboot, the change takes effect. You can use the netstat -m command to view current system stream resources. The third line from the bottom of the command output will show that the total configured streams memory has been changed from 2048 KB to 8000 KB.

By default, the name of a pseudo terminal consists of six characters, for example, ttyp50. But some banking services do not support pseudo terminal names containing six or more characters. Therefore, you must modify the names to 5-character long names. The following example shows the steps:

1. Kill all the current main and child ttyd processes.

2. Modify pseudo terminal names in configuration file ttyd.conf, for example:

   Original: ttyp30 10.110.96.11 0

   Modified: ttya0 10.110.96.11 0

3. Modify 6-character pseudo terminal names to 5-character ones with the following commands:

   # mv /dev/ttyp30 /dev/ttya0
   # mv /dev/ptyp30 /dev/ptya0
   

4. Modify pseudo terminals attributes with the following commands:

   # chmod 666 /dev/ttya0
   # chmod 666 /dev/ptya0
   

5. Synchronize with the following command:

   # sync
   

6. For active terminals, add corresponding pseudo terminal configuration in system file inittab by using the following command:

   a0:234:respawn:/etc/getty ttya0 m
   

7. Add configuration entry for pseudo terminal ttya0 in the banking service configuration file.

8. Restart the ttyd program.

When the program restarts, 6-character VTY names have been changed to 5-character names.

A terminal does not display the login interface in the following cases:

• Sometimes, when you kill the main ttyd process, some banking service process may remain. In this case, when you restart ttyd, the terminal cannot be opened.

• The terminal has baud rates different from those of the asynchronous interface.

• The corresponding device is not configured in the inittab file.

• The router and the Unix server use different application modes. For example, the Unix server may use the many-to-one mode and the router may use the TTY one-to-one mode. The router only supports TTY one-to-one mode.

Solution:

• For the first case, you may check the UNIX server log for a message similar to "open ptyp10 failed: I/O error." If you find a message like this, execute the following command on the Unix server:

  # ps -ef | grep ttyp10

Then kill all the displayed processes associated with ttyp10.

• For the second case, you must reconfigure the baud rates to be consistent.

• For the third case, you must configure the corresponding device in the inittab file.

• For the fourth case, you must configure the router and the Unix server to use the same application mode.

Use the ttyd administration program to check the system resource occupation rate of the Unix server. If the rate is relatively high, locate which service process is abnormal and, if necessary, kill the process.

If the rate is not high, open the ttyd configuration file to examine whether the sendsize and readsize options are properly configured. For low speed WAN links (at 9600 bps for example), the two options must be modified accordingly.

In addition, for higher terminal echoing speed, TTY one-to-one mode is recommended.

Some banking services require certain types of terminal emulation. Terminal emulation type is configured for each pseudo terminal in system file /etc/ttytype on the Unix server. When upgrading network devices, if you modify pseudo terminal numbers, you must edit the system file to add terminal emulation types for the new pseudo terminals. Taking ttyp50 as an example, you must add the following line to the file /etc/ttytype:

    vt100  ttyp50

If a pseudo terminal is configured with no terminal emulation type in file /etc/ttytype on the Unix server, the pseudo terminal uses the default emulation type unknown, and the prompt message at login displays "TERM = (unknown)".

After ttyd is started, if the log does not prompt that a terminal is open, the terminal is not open. Check the configuration file to see whether the terminal has a valid name.

If other configurations are all correct but the log shows that some pseudo terminals cannot be opened, check whether the terminals are under directory /dev. If not, try to use another existing pseudo terminal or create the pseudo terminal. If yes, check whether a process is using the pseudo terminal.

If a terminal is correctly connected to the router, its status should be OK when you use the display rta command. If its status is UP, terminal access has not been started, and you must use the rta server enable command in system view on the router to enable terminal access.

• Verify that the same application mode (TTY many-to-one or TTY one-to-one) is configured on both the router and the Unix server.

• Verify that the router and Unix server are configured consistently and that the configurations comply with the parameter configuration conventions. Most mistakes result from inconsistent configurations.

• Check whether source address binding is configured. With source address binding configured, the router IP address configured on the Unix server must be the bound IP address.

• Verify that correct routes are configured on both the router and Unix server.

Check whether test, redrawing, switching hotkeys and the like are configured. Hotkey values may conflict with data. You can change the hotkey values.

Check whether the application mode is many-to-one, which may cause data for terminals to fall into confusion. Upgrade to a router version supporting TTY one-to-one mode and switch to TTY one-to-one application mode.

When a terminal is listing directories or outputting data, pressing the menu switching hotkey does not bring up the menu. Perform VTY switching when the terminal is idle.

• Check whether the asynchronous interface is configured with the undo modem command.

• Verify that the terminal cable is OK.

• Verify that the converter connecting the terminal and the router is wired correctly.

Check whether the listening ports configured in the configuration files are in conflict.

Examine the configuration file to see whether the same application mode is configured on the router and the Unix server. This problem occurs if the Unix server uses the many-to-one mode and the router uses TTY one-to-one mode.

View the hardware versions of the interface modules by using the display version command.

Confirm that the correct hardware versions of the interface modules are being used. 8AS modules have two hardware versions: 1.x and 2.x. 8AS modules with a hardware version of 1.x do not support card swiping. Those with a hardware version of 2.x support it. No such problems happen to any other interface modules.

Some terminals undergo a slow initialization process after power-on, so they may drop the menu interface sent by the router and display a blank screen. Press the menu hotkey or any non-function key to bring up the menu interface.