The services file (SystemFolder\drivers\etc\services) describes port numbers and associated protocols. For each port used by Operations Sentinel, you must specify the port number and protocol in this file on the Operations Sentinel server. You must log on as the administrator to update this file. The format of each line of the file is
service-name port/protocol communications-parameters # commentwhere:
service-name
Specify names with the prefix spo_ as service names of managed systems that you define using Operations Sentinel Console. Specify names with the prefix eai_ as service names in action templates of alert policies.
port
is the logical number (also called service tag) of a network port or a physical serial port on the Operations Sentinel server or on the port of a system to be used as a connection. The port numbers are listed in the following “Port Numbers” subsection.
protocol
name for the Operations Sentinel. It can be one of the following:
| spo_serial | Direct connection through serial port. |
| spo_ats | ATS or NAS connection. |
| spo_telnet | TELNET or terminal/communications server connection. |
| eai_ats | ATS or NAS connection for modems or serial devices. |
| spo_ssh | Secure Shell. Dynamically determines most secure versions possible. |
| spo_ssh1 | Secure Shell version 1. |
| spo_ssh2 | Secure Shell version 2. |
A protocol of spo_serial identifies a serial port on the Operations Sentinel server. Serial ports on a Windows server are named COM1, COM2, and so on. So the port specification is COM1, COM2, and so on. If expansion ports are added, they are identified by incrementing the number after COM. Normally, COM3 would be the first expansion port. See port settings of your server under the Device Manager for the explicit values.
A protocol of spo_ats or eai_ats identifies an ATS or NAS port number.
A protocol of spo_telnet identifies a port number on a managed system on which its TELNET server is listening (default port number is 23). The spo_telnet service specification can be used by more than one connection.
A protocol of spo_ssh, spo_ssh1, or spo_ssh2 identifies a port number on a managed system on which its Secure Shell server is listening (default port number is 22). The spo_ssh, spo_ssh1, or spo_ssh2 service specification can be used by more than one connection.
communications-parameters
are for external alert notification modems and serial devices only.
comment
is any optional descriptive information about this entry. Comments must follow the # character.
Operations Sentinel assumes the port specifications "spo_telnet 23/spo_telnet" unless it is overridden by another specification in file SystemFolder\drivers\etc\services on the Operations Sentinel server.
Operations Sentinel assumes the port specifications “spo_ssh 22/spo_ssh”, “spo_ssh1 22/spo_ssh1”, and “spo_ssh2 22/spo_ssh2” unless they are overridden by other specifications in file SystemFolder\drivers\etc\services on the Operations Sentinel server.
Port Numbers
The following table lists the port numbers.
| System | Physical Port Label Range | Logical Port Label Range |
| Cisco 2500 Series Access Servers | 1–16 | 2001–2016 |
| Unisys 8- to 64-port ATS or NAS | 1–64 | 1–64 |
Note: Operations Sentinel uses TELNET protocol to communicate to terminal/communications servers to manage a connected system. To indicate the use of TELNET protocol to the Cisco servers on a specific port, Operations Sentinel must connect using the physical port number offset by 2000 (for example, physical port 1 is accessed by 2001, while port 16 is accessed by 2016). Therefore, when using these servers, you must specify spo_telnet as the type of service with a port number in the range 2001–2016.
Offsetting the Physical Port Number
Operations Sentinel uses TELNET protocol to communicate with terminal/communication servers (including the Unisys ATS/NAS devices). This type of interface is usually available on other servers as well. These devices would normally provide the facility for a TELNET server on each physical serial port. This type of TELNET server is designed so that the establishment and negotiation of the protocol does not affect the data traffic flow from the serial port to Operations Sentinel.
In the case of the Unisys ATS/NAS devices, this configuration is established by specifying the spo_ats service in the file SystemFolder\drivers\etc\services. Operations Sentinel accepts the specification of the port number on the spo_ats line and offsets it with 5000 to gain access to the TELNET server for that physical port.
For other terminal/communication servers, this offset is probably different, requiring a different specification in the file SystemFolder\drivers\etc\services. For example, the Cisco 2500 Series Access Servers provide this facility by offsetting the port number with 2000. To properly configure Operations Sentinel to access a port on the Cisco server, you must specify TELNET protocol and the TCP/IP port that the TELNET server on the terminal/communication server is using.
Examples of the Port Offset Specification
The following examples illustrate the port offset specification further.
The following specification in the file SystemFolder\drivers\etc\services defines a spo_ats connection using a Unisys ATS/NAS device.
systemA 05/spo_ats
The TCP/IP port to which Operations Sentinel connects is 5005. The spo_ats protocol indicates that the connection is being made to a Unisys ATS/NAS. Because of this, Operations Sentinel connects to the TELNET server for physical port 5 by offsetting the value by 5000, giving a port number of 5005.
The same connection could be configured by using the following specification in the services file. The spo_telnet specification indicates that the connection is TELNET and the TELNET server is listening on TCP/IP port 5005.
systemA 5005/spo_telnet
Use the following specification in the services file to define a managing connection through a Cisco model 2509 server, which has the system you wish to manage connected on its serial port 3.
systemB 2003/spo_telnet
If you are using a terminal/communications server other than the Unisys ATS/NAS or Cisco 2500 Series Access Servers, the specification for the port offset for the TELNET server is probably different. Refer to your server documentation for the proper value.
Examples
To connect a system with a service name of puma to port 8 on an 8-port PCI expansion controller, where the 8 ports of the expansion are assigned to COM3-COM10, corresponding to port 1- port 8, enter the following line in the services file (SystemFolder\drivers\etc\services):
puma COM10/spo_serial
To connect a managed system with a service name of jaguar through ATS or NAS port 3, enter the following line in the services file:
jaguar 03/spo_ats
To connect to a managed system through a common TELNET service name of spotelnet, enter the following line in the services file:
spotelnet 23/spo_telnet
To connect to a managed system through a Cisco 2509 Access Server on port 5, enter the following line in the services file:
aix3 2005/spo_telnet
To connect a modem with a service name of remote-alert-modem through ATS or NAS port 3, enter the following line in the services file:
remote-alert-modem 03/eai_ats
To connect to a managed system with a service name of alert-modem through a Cisco 2500 Access Server on port 4, enter the following in the services file:
alert-modem 04/eai_ats OFFSET 4000