Configuring rotaries includes the following options:
• Defining multiple rotaries with one file entry.
• Assigning rotaries auxiliary Internet addresses.
• Using the DNS server to define multiple rotaries.
• Assigning rotaries TCP port numbers.
• Configuring visibility.
• Configuring camp-on.
• Configuring the protocol.
• Assigning phone numbers to rotaries
• Configuring port selection.
Defining Multiple Rotaries with One Entry
You can include more than one Remote Annex in a single file entry in the rotary section of the Remote Annex configuration file by separating the ports@locations field with semicolons. The following entry defines a rotary named modems that resides on two different Remote Annexes. The rotary on annex01 has seven ports; the rotary on the Remote Annex with the Internet address 132.245.6.15 has one port.
modems: 1,4,7,13-16@annex01; 10@132.245.6.15
When the user accesses annex01 using a telnet command, the port server displays:
% telnet annex01 Trying...
Connected to annex01.
Rotaries Defined:
modems 1,4,7,13–16 cli
Enter Annex port name or number:
When the user accesses the Remote Annex at 132.245.6.15, the port server displays:
% telnet 132.245.6.15 Trying...
Connected to 132.245.6.15.
Escape character is "^]".
Rotaries Defined:
modems 10 cli
-Enter Annex port name or number:
Assigning Auxiliary Rotaries Internet Addresses
An auxiliary address allows you to assign an Internet address that allows a connection directly to the rotary. The user can access the rotary by entering the unique auxiliary address using the telnet or rlogin commands. The auxiliary address must adhere to the standard network addressing conventions of your network.
Using auxiliary addresses to access a rotary changes the behavior of the port server. The port server does not display rotary names; instead, the port server attaches to the first available port in the rotary.
Using telnet, the command line looks like this:
modems: 1,4,6-9@annex01+132.245.6.80
Using rlogin, the command line looks like this:
modems: 1,4,6-9@annex01+132.245.6.80/513
modems: protocol=rlogin 1,4,6-9@annex01+132.245.6.80
Users can issue the following command to access the first available port in the rotary:
% telnet 132.245.6.80 Trying...
Connected to 132.245.6.80.
Escape character is "^]".
Attached to port 4.
You can also add the rotary name and the auxiliary address to /etc/hosts or to the host name database so users can access the rotary directly by name:
132.245.6.80 modems
Users can use the name modems and access the first available port in the rotary:
% telnet modems Trying...
Connected to 132.245.6.80.
Escape character is "^]".
Attached to port 7.
Using the DNS Server to Define Multiple Rotaries
If you are using a Domain Name Service (DNS) server on the network, you can create an entry with multiple rotaries as described above, assign Internet addresses to these rotaries, and create entries in the name servers database for the names of the rotaries. This allows users to request a rotary name using the telnet command.
With the DNS server, the Telnet request attempts to connect to the first IP address returned by the name server. If that connection is unsuccessful, it moves on to the next connection, and so on until a connection is available. Using the following example, one entry defines rotaries on two Remote Annexes:
modems:direct_camp_on=never\
1,3,8,11@annex01+132.245.6.90;\
6-8@annex05+132.245.6.91
In the DNS server’s database, create two entries for the name modems with two different Internet addresses. For example, using a BIND name server:
modems IN A 132.245.6.90 IN A 132.245.6.91
When the user issues a telnet command to modems, Telnet tries to locate an available port. First, it tries port 1 on annex01, next port 3, followed by port 8, and so on until an available port is located (assuming camp-on is set to direct_camp_on=never):
% telnet modems Trying...
Connected to 132.245.6.80.
Escape character is "^]".
Attached to port 6.
When creating multiple rotaries under one name, always disable camp-on so that Telnet tries the next available port if the first connection fails.
Since a modem was not available on the first Remote Annex, telnet automatically crossed over to the second Remote Annex, annex05.
Assigning Rotaries TCP Port Numbers
TCP port numbers in the 6000 range allow you to assign a TCP port number to a rotary that the user can enter with the telnet or rlogin commands. The last three digits of the port number are arbitrary; but the TCP port numbers must be unique for each Remote Annex.
A special version of rlogin, one that accepts TCP port numbers, is needed to use TCP port numbers with rlogin.
When users include a TCP port number in the 6000 range with the telnet or rlogin commands, they are attached to the first available port in the rotary. Defining TCP ports for rotaries allows the users to avoid having to select a particular serial port, especially if auxiliary Internet addresses cannot be used. The following example is an entry in which a TCP port
Users can issue the following command to access the first available port in the rotary:
% telnet annex01 6080 Trying...
Connected to annex01.
Escape character is "^]".
Attached to port 9.
Configuring Visibility
Configure visibility for rotaries using the keyword ps= along with the arguments visible and invisible. The port server displays a visible rotary’s name when users telnet or rlogin to the Remote Annex’s primary Internet address. An invisible rotary prevents users from seeing the name if they use telnet or rlogin to connect to the Remote Annex and further hides details of the connection.
Only rotaries that can be accessed via an auxiliary Internet address or a TCP port in the 6000 range can be defined as invisible. Rotaries without auxiliary Internet addresses or TCP ports in the 6000 range are always visible. Following is an example of an entry that makes the HostC rotary invisible:
HostC: ps=invisible 1,4,6-9@annex01+132.245.6.80
Users that use telnet or rlogin to connect to annex01 do not see the name;
users that use telnet or rlogin to connect to HostC see the sequence illustrated inAssigning Auxiliary Rotaries Internet Addresses on page 4-84.
Configuring Camp-on
Camp-on applies to rotaries with an auxiliary Internet address or auxiliary TCP port. It is the process of waiting for the next free port in the rotary if all of its ports are busy when a connection is attempted. Configure camp-on using the keyword direct_camp_on= along with the arguments ask, always, and never.
The ask argument indicates that the port server asks the user to camp-on;
always causes the port server to camp-on automatically; never causes the port server to refuse the telnet or rlogin connection if the rotary is full (raw rotaries default to never). The default is ask.
You must define the alternate IP address or TCP port for the rotary.
Camp-on applies when using telnet or rlogin to access this alternate address or TCP port.
Configuring the Protocol
Define the protocol between the port and the device using the keyword protocol= along with the arguments telnet, rlogin, tstty, raw, and binary.
protocol=telnet The setting protocol=telnet configures telnet as the protocol between the port and the device. This is the default setting.
protocol=rlogin The setting protocol=rlogin configures rlogin as the protocol between the port and the device. Another way to configure rlogin as the protocol is by specifying TCP port 513 in the rotary section of the configuration file.
protocol=raw The setting protocol=raw configures a raw rotary. A raw rotary passes data directly to and from the serial device -- no data processing occurs.
Raw rotaries are invisible. Generally, raw rotaries are accessed by programs that use the system network facilities, such as the socket interface in BSD systems, to open a connection and to perform whatever functions are required for the device.
The setting direct_camp_on=never is the default for raw rotaries; ask cannot be used. Following is an example of a raw rotary consisting of ports 1, 2, 3, and 8 on a Remote Annex whose Internet address is 132.245.6.32. The rotary is accessed through TCP port 6300:
strip-record: protocol=raw direct_camp_on=always\
1-3,8@132.245.6.32/6300
protocol=binary The setting protocol=binary configures a binary rotary. In this configuration, the Remote Annex negotiates with the host to operate in telnet binary mode in both directions:
strip-record: protocol=binary direct_camp_on=never 1-3,12@132.245.6.30
Assigning a Phone Number to a Rotary
The keyword phone= defines a phone number that the Remote Annex dials automatically when a user connects to the rotary to which the number has been assigned.
Configuring Port Selection
The keyword select= defines the order in which the rotary selects ports.
If select=first, the rotary selects the first available port in the port_set;
select=next directs the rotary to keep track of the last port that was selected, and to start its search from that point.
In the following example, the user connects to the rotary modems and is attached to port 1; after disconnecting and then re-connecting to modems, the user is attached to port 2:
modems: select=next 1-5@annex01
% telnet modems Trying...
Connected to annex01.
Escape character is "^]".
Attached to port 1.
^]
telnet> quit
% telnet modems Trying...
Connected to annex01.
Escape character is "^]".
Attached to port 2.