NTX_CHADDR(1) — USER COMMANDS

NAME

ntx_chaddr − change the address and call-type for a channel

SYNOPSIS

ntx_chaddr [ −d device ] [ −c service ] [ −p port ] [ (−i address) | default ] channel

DESCRIPTION

Ntx_chaddr changes the Internet address, protocol port, and call-type associated with an MVME339 channel. This command allows the system administrator to configure groups of channels as call-out to specific destinations or as call-in to accept connections to a specific address or port. The channel is the MVME339 channel index. A channel that has not been configured cannot be accessed.

The channel argument is either a tty device file name (e.g., /dev/hty0) or an NTX channel ID for the board device. Note that the channel IDs start at zero for each board; therefore, the channel IDs do not necessarily correspond to the system’s minor device numbers. The channel is first parsed as a decimal number and if successful is used as a channel ID; otherwise, the channel is used as a tty device file name.

If the −c, −i, −p, and default options are not selected, the current settings for the channel are displayed.

If the −c option is not specified, the channel is configured as call-in. When the host opens a call-in channel,the MVME339 will only accept a connection to the assigned address and port. The service that a call-in channel will use is determined by the port of the connection request. The ports are assigned services with ntx_pserv(1) and the service assigned to the port must be a known terminal service for a connection to be accepted. Assigning a call-in channel to port 0 has the special meaning of accepting a connection to any port which has a known terminal service assigned. The following are the known terminal services: telnet, rlogin, or nop. If the port or address is not specified, the previous value is retained. The keyword default can be used to set the address back to the system default (ntx_ifcfg(1)). The MVME339 will automatically configure itself when a new local Internet address is specified.

If the −c option is specified, the channel is configured as call-out. The service must be one of the known terminal services. When the host opens a call-out channel, the MVME339 will attempt to establish a connection to the assigned address and port. The service that a call-out channel will use is the assigned service and is not determined by the assigned port. If the −p option is not selected for a call-out channel the host database (typically /etc/services) will be searched for the the port assigned to the service, and if not found, an error is returned. If address is not specified, the previous value is retained.

Ntx_chaddr updates one channel at a time and must be issued multiple times to configure more than one channel. An error is returned if the default Internet address has not been configured (ntx_ifcfg(1)).

OPTIONS

−dSets the MVME339 raw device file name. This option will override the default MVME339 device name of /dev/xedt/mvme338_c0. If the channel argument is a channel ID, this option specifies the board for the channel ID. If the channel is a tty device file name, this option can specify any valid MVME338 raw device file name.

−cEnables the channel as call-out. A call-out channel will attempt to establish a connection to the address and port specified with the selected service when the host opens the channel. Valid services are: telnet, rlogin, and nop.

−pSpecifies the local protocol port for call-in channels or the remote port for call-out channels (see −c). A local port of 0 has a special meaning that allows a call-in channel to accept connections to any port with a known terminal service (ntx_pserv(1)).

−iSpecifies the local Internet address of the MVME339 board for call-in channels or the remote address for call-out channels (see −c). Use the keyword default (without the −i) to set the address back to the system default (ntx_ifcfg(1)). The default keyword is not allowed if the −c option is also selected.

FILES

/dev/xedt/mvme338_c0
~/include/ntx/net.h