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How can I disable security alerts like "The server's host key is not cached in registry, bla-bla-bla", "host identity is changed, there is man-in-the middle", etc

They are needless in cloud hosting environment, where a lot of new server instances appear. And also, it is quite normal if there eventually will be a new server on the same IP.

In linux ssh client I have done it with the following lines in my .bashrc:

alias ssh='ssh -o "StrictHostKeyChecking no" -o "UserKnownHostsFile=/dev/null" -o "CheckHostIP=no"'
alias scp='scp -o "StrictHostKeyChecking no" -o "UserKnownHostsFile=/dev/null" -o "CheckHostIP=no"'
But how to do it in putty?

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migrated from Feb 12 '10 at 21:53

This question came from our site for professional and enthusiast programmers.

There doesn't seem to be any hope:

No, there isn't. And there won't be. Even if you write it yourself and send us the patch, we won't accept it.

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Hm. Maybe a 3rd party launcher... – Anonymous Feb 12 '10 at 21:31

I use AutoHotkey to create a script that runs in the background and scans for any particular warning popups that I don't care about, closing them automatically.

    SetTimer, ClosePopups, 100  ; Check every 1/10 of a second

    ; Putty popup definition
    IfWinExist, PuTTY Security Alert
        WinActivate PuTTY Security Alert
        Send !y ; Press Alt+Y

    ; Here's another example of a popup definition, for reference
    IfWinExist, Cisco AnyConnect Secure Mobility Client
        WinGetText, output, Cisco AnyConnect Secure Mobility Client
        if output contains Connecting to this server may result in a severe security compromise
            WinActivate Cisco AnyConnect Secure Mobility Client
            Send {Tab}{Space}

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After much searching, found the answer here:

echo y | ssh -pw yourpassword

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That link is now unavailable, and there is no program named ssh in PuTTY, but there is a program plink which does fix the cache with those arguments and input, although for me it (in 0.64) it doesn't exit properly unless I add -m NUL. – dave_thompson_085 Jun 22 at 1:10

You could try the following option:

putty settings

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They should defiantly add a feature to disable this popup. We have thousands of wireless CPEs that we'd like to be able to script batch settings changes via SSH. The settings we want to change are not available for batch processing in the platform management software offered by the manufacturer, however, it can be done via SSH and scripts... These devices come with SSL certs and SSH enabled from the manufacturer for remote diagnostics but they are obviously self signed and the IPs change.

The comment that, "No, there isn't. And there won't be. Even if you write it yourself and send us the patch, we won't accept it." is pretty narrow minded, its of concern if your talking about paid public certs assigned to a public server or something. It's completely useless and annoying to people working heavily with run of the mill network attached devices that you need to remote into and would never need to buy a cert for.

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The only certificates SSH ever uses are OpenSSH's custom ones, which never cost anything and don't work with PuTTY anyway. You appear to be thinking of SSL/TLS which IS NOT SSH. – dave_thompson_085 Jun 22 at 1:13
The site's Q&A format reserves answers for solutions to the question. This post is really a comment rather than an answer. You can always comment on your own posts, and once you have sufficient reputation you will be able to comment on any post. Non-answers tend to attract downvotes and are subject to deletion. – fixer1234 Jun 22 at 3:56

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