still seeking, is anyone have a shell server I can use for a test?

Tue Aug 7 23:07:09 UTC 2018

Hi,

To me this subject starts sounding more like debugging communications problems than providing simple shell access using ssh.

First of all if something doesn't work it would be good if you draw a picture of the communications path. You need to know what devices there are and which protocols and ports are allowed on the path. Is there address translation used (NAT) on that path? If there is NAT where and how is it used?

Now the thing is that ISPs usually restrict traffic. Quite often they use NAT if they provide the router for you. Specially so if the connection is for household use. The same applies for most connections that I know for SMB use. Even enterprise connections may filter ports and protocols. This could also be done at the ISP end.

If you try making a connection to an arbitrary port it might very well be that it is your ISP banning the traffic. Even well known ports might get blocked. It could also be your firewall or router restricting the permitted ports and protocols. It could be your host routing table. It could be your host firewall. It could be your code which doesn't work as expected. It could be something else which didn't come to my mind.

If you want to be scientific you need to be systematic. Try these steps:
a) Check your host routing table
b) Check your host firewall
c) Use a traffic analyzer on your host (tcpdump would do)
d) Use a traffic analyzer on all the links and devices between the communications endpoints
e) Document all the steps, changes, everything you do.

Please remember to repeat the same code and arguments when checking the next segment. Don't change anything (code, parameters, ports, etc) without documenting first! There must be a sound reason for every change. Don't assume, analyze.

All this could be called systematic fault finding. Don't worry, even professional sysadmins are not always familiar with doing things systematically. This needs to be taught, learned and practised.

My two cents,
Birdie

On August 7, 2018 6:10:31 PM UTC, Linux for blind general discussion <blinux-list at redhat.com> wrote:
>Just so.  no exchange took place whatsoever.
>While I am certain Janina's structure works for others, it is not
>suitable 
>for the small tests  we wish to perform, generating atypical errors
>from 
>the  ones we even expected laughs.
>We are moving on making her comments unimportant to our goals.
>
>Karen
>
>
>
>On Tue, 7 Aug 2018, Linux for blind general discussion wrote:
>
>> Since Karen mentions me by name, let me simply note there's no
>evidence
>> in my logs that she ever reached my machine.
>>
>> I also provided ssh over a high port that she also never reached.
>>
>>
>> Best,
>>
>> Janina
>>
>> Linux for blind general discussion writes:
>>> Hi folks,
>>> I am still seeking a simple, based on the testing needs  of the
>engineers
>>> working with me here  server if possible.
>>> Granted I have already tested a couple of examples, but suppose I
>desire
>>> being a touch more scientific.
>>> So, again if anyone has or can suggest a server using alternative
>port
>>> settings than 22 for ssh, let  me know off list.
>>> Janina's server times out according to -v information.
>>> Our agency is pressed for time to find a solution, which may end up
>being
>>> hostgator for our accounts  in the end.
>>> Thanks,
>>> Karen
>>>
>>>
>>>
>>> _______________________________________________
>>> Blinux-list mailing list
>>> Blinux-list at redhat.com
>>> https://www.redhat.com/mailman/listinfo/blinux-list
>>
>> -- 
>>
>> Janina Sajka
>>
>> Linux Foundation Fellow
>> Executive Chair, Accessibility Workgroup:	http://a11y.org
>>
>> The World Wide Web Consortium (W3C), Web Accessibility Initiative
>(WAI)
>> Chair, Accessible Platform Architectures	http://www.w3.org/wai/apa
>>
>> _______________________________________________
>> Blinux-list mailing list
>> Blinux-list at redhat.com
>> https://www.redhat.com/mailman/listinfo/blinux-list
>>
>>
>
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