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DNS resolver package for IOS Tcl

I've ported the dns package of the Tcl standard library to Cisco IOS. You can download it from my web site and install it on your router in just a few steps:

  1. Extract all the files from the ZIP archive and copy the Tcl files into a subdirectory on your router's flash (I would recommend you use flash:tcllib/dns).
  2. Configure the package initialization script with the scripting tcl init flash:tcllib/dns/pkgIndex.tcl global configuration command
To test the successful installation, start the Tcl shell from the command prompt and try to load the DNS package:
router(tcl)#package require dns


  1. Hi, any plans on making UDP support available?

  2. Can't do it, Tcl has no built-in UDP support and all Tcl UDP packages rely on an underlying native C library. Since you cannot write an executable library for IOS (yet?), there's nothing you can do.


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