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Tclsh is broken in 12.4T

As Roddie pointed out in his comment, in some cases tclsh writes its output to the first line (usually console), not to the current line as expected. This “feature” has been introduced in IOS release 12.4(6)T1 (12.4(6)T is still OK) and fixed sometime before IOS release 12.4(11)T; 12.4(9)T is still broken (and I haven't tried all the other interim rebuilds ... or shall I call them rebreaks?).


  1. Ivan,

    In my case, the router is running 12.4(12).

    The Cisco Bug ID is CSCsf07232.

    Looks like it's present (and fixed) in a good number of versions.

    Fixed in:
    12.4(11.1)T, 12.2(32.08.29)SRB, 12.4(10.8)T01, 12.2(32.08.11)SX19, 12.2(18.06.05)SXF, 12.2(18)SXF07, 12.4(13.3), 12.4(13.5)T, 12.2(33)SRA04

  2. Thanks a lot for figuring this out for the rest of us. I sort-of gave up on the bug navigator; a lot of the interesting bugs are hidden or have no description :)


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Ivan Pepelnjak, CCIE#1354 Emeritus, is an independent network architect. He has been designing and implementing large-scale data communications networks as well as teaching and writing books about advanced technologies since 1990. See his full profile, contact him or follow @ioshints on Twitter.