Server Tuning Guide – Telnet Source Address and per_source

StayLinked is different from other Telnet Clients in that it is designed to host multiple connections from a single process. This means that all telnet connections initiated by StayLinked will appear to the telnet server as connections from a single source.

Many telnet servers include a limit on the number of telnet connections from a single source IP. This system value typically affects Linux and Unix systems, but can be a parameter of any Telnet server. If the telnet server reaches this limit, it may automatically terminate further connection requests until the number of connections is reduced. Platforms like Red Hat Enterprise Linux may store this value in the /etc/xinetd.conf file. This file can contain a wide range of settings, including limitations and redirections for incoming connections.

Limitations imposed by the telnet host for source addresses can be specific to address but are not specific to the type of telnet client. This means it is easy to replicate this limit using other telnet clients from the same source address. For example, opening multiple PuTTy sessions from the same PC would have the same limitations. Testing additional connections from other machines or devices would not be able to replicate this issue unless the host has a limit on the total number of connections instead of a per-address limitation.

The StayLinked Server cannot spoof or fake the connection source from another IP. Source limitations imposed by the hosted application would have the exact same issue if connections were coming from a network using NAT, PC users wanted to have more than one connection open at a time, or customers using shared machines or terminal services.

Most hosted applications have a configuration option to use some configurable value to identify unique connections, such as; a workstation ID/name/number, answerback message, or user profile. Many applications use a startup script to identify and direct incoming connections. These startup scripts can be modified to use any StayLinked variable or Host API to return a unique identifier. StayLinked offers several variables that can be used in StayLinked startup scripting, such as; [deviceip], [deviceid], and [devicemac].