I tried to reach my machine through public ip  $ ssh me@23.100.101.9 me@23.100.101.9: Permission denied (publickey).   the authorized_keys  gaowei@alpha:~:  me@host:~/.ssh: $ cat .ssh/authorized_keys ecdsa-sha2-nistp521 AAAAE2VjZHNhLXNoYTItbmlzdHA1MjEAAAAIbmlzdHA1MjEAAACFBAHuttEBp2wI31Ip4R9dLImfw+B1IiRApWM7RSb2ko2Z51O5kXEvLMhlr3pwszZ9yUZkfv3yqHpweqNjDbKUyDMmxABcbfBVz+JfTS+o3Dta6qenAIykepiuZu3LHZUpjx/A7HVkVnI9wnc2GN6iWkZYQvJa6sMC9dxE5rjFFu5K7E9ztw== me@host.local   Why it not working?  The updated authorized keys  Connet to local from it's public ip address.  $ cat .ssh/authorized_keys ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDBj3chjFnpxtHfeSUJVFv6fIN4CPZmIlBzuhMOOJNpovQqBc5JAhrz9uRiQIMHPD2vW+QJYiK08+6pCHthQSFrSLokLXTJfqEvb+frNEc6HvPPglGY3//97lbxR+CQYTjB/XgvnrP8sWKRt4VLfCwtCE6TqdVMx1y9SUmf7FghbHWhUioezdJaFJmfR+WVtELrUSwsc5eXcF+RS74eXEys2/v7LJF2JNYZxu0+Et7EwgxliA/5bOo6jTKBSZttBZPlsn2N7/GXnDilfAy06Iuc8MzMFCrAajQx8Nd4DG5Y33YyNVfU7eat9btUqNhpKGC+b5FGY4mkIPA2tammnjkx ssh-rsa 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****@live.com ssh-rsa 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 ****@gmail.com ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDBj3chjFnpxtHfeSUJVFv6fIN4CPZmIlBzuhMOOJNpovQqBc5JAhrz9uRiQIMHPD2vW+QJYiK08+6pCHthQSFrSLokLXTJfqEvb+frNEc6HvPPglGY3//97lbxR+CQYTjB/XgvnrP8sWKRt4VLfCwtCE6TqdVMx1y9SUmf7FghbHWhUioezdJaFJmfR+WVtELrUSwsc5eXcF+RS74eXEys2/v7LJF2JNYZxu0+Et7EwgxliA/5bOo6jTKBSZttBZPlsn2N7/GXnDilfAy06Iuc8MzMFCrAajQx8Nd4DG5Y33YyNVfU7eat9btUqNhpKGC+b5FGY4mkIPA2tammnjkx
I am trying to connect to a Linode (running Ubuntu 12.04 LTS) from my local machine (also running Ubuntu 12.04 LTS)  I have created a private and public key on my local machine and copied my public key to my Linode's authorized_keys file.  However, whenever I try to ssh to my Linode I get the error message Permission denied (publickey).    It's not a problem with how ssh is set up on my Linode because I can ssh to it from my Windows machine using key authentication.    In my .ssh directory on my local Ubuntu machine, I have my id_rsa and id_rsa.pub files.  Do I need to create an authorized_keys file on my local machine?    EDIT:  This is what I get when I run ssh -vvv -i id_rsa [youruser]@[yourLinode]:  debug3: authmethod_lookup publickey debug3: remaining preferred: keyboard-interactive,password debug3: authmethod_is_enabled publickey debug1: Next authentication method: publickey debug1: Offering RSA public key: id_rsa debug3: send_pubkey_test debug2: we sent a publickey packet, wait for reply debug1: Authentications that can continue: publickey debug2: we did not send a packet, disable method debug1: No more authentication methods to try. Permission denied (publickey).
What is the possibility of a railgun assisted orbital launch? Basic facts: The  is 2.4 miles deep.  Railguns  of a projectile on the order of 7.5 km/s.  The Earth's  is 11.2 km/s.  It seems to me that a railgun style launch device built into a deep shaft such as an abandoned mine could reasonably launch a vehicle into space.  I have not run the calculations and I wouldn't doubt that there might be issues with high G's that limit the potential for astronauts on such a vehicle, but even still it seems like it would be cheaper to build such a launch device and place a powerplant nearby to run it than it is to build and fuel single-use rockets.  So, what is the possibility of a railgun assisted orbital launch?   What am I missing here?  Why hasn't this concept received more attention? How to make X.org listen to remote connections on port 6000? This is on Ubuntu 10.10 (Maverick Meerkat) 64-bit desktop.  I want to make my X server listen to remote connections from clients in other machines on the local network. I know about ssh -X and that is not what I want. I vaguely remember changing something like TCPListen from no to yes, but I don't remember where this change should be applied.  I'm interested in either a GUI method or a CLI one.  PS editing /etc/X11/xinit/xserverrc to remove the -nolisten tcp option and rebooting does not work. E:Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages Does Google penalize daily updated  tags in sitemaps if the data is not daily updated? If $x+{1\over x} = r $ then what is $x^3+{1\over x^3}$? If $$x+{1\over x} = r $$ then what is $$x^3+{1\over x^3}$$  Options: $(a) 3,$ $(b) 3r,$ $(c)r,$ $(d) 0$ How to return a part of an array in Ruby? Google crawlers screen size Imagine a I have two types of images (A and AAA(heavier)) for the same website: depending on the size of the screen it will show one image or other.   Now I'm wondering what images (A or AAA) loads the Google crawler when it visits my site.   In other words: has the Google crawlers any "screen size"?  I suppose, in case the it loads the A images, the page-speed puntuation will be better than if it loads the images AAA. Is sudo required for installing VMware Tools? I'm trying to install VMware Tools in Ubuntu 16.04. Should I do this by using sudo? Why? Finding places to play Magic the Gathering games A friend of mine recently got MTG for the XBox and is talking us into getting real cards.  I'm all up for starting but I dread the idea of playing the same two people over and over with no change epically since one of them is over competitive and exploits every loophole he can to win.  Does anyone know of any a reliable (not just google it) way to find places where people play MTG? Suppose $m_1, m_2, m_3,\ldots, m_k &gt; 1$ and not necessarily pairwise relatively prime. Also $a_1, a_2,\ldots, a_k\in\Bbb Z$. What can we say about the solutions of the following congruence equations: $\begin{align*} x&amp;=a_1\mod m_1\\ x&amp;=a_2\mod m_2\\  &amp;\phantom{1}\vdots\\ x&amp;=a_k\mod m_k \end{align*}$ Remove specific duplicates (all but latest) When removing duplicate rows, using the below query from  tutorial, how would I go about forcing which of the found duplicates to remove?  DELETE FROM dbo.ATTENDANCE      WHERE AUTOID NOT IN (SELECT MIN(AUTOID) _ FROM dbo.ATTENDANCE      GROUP BY EMPLOYEE_ID,ATTENDANCE_DATE)    And this works great. The reason why I am using this one is because the only unique id available is one in the IDENTITY column. And to determine if there are duplicate rows I have to look at a combination of multiple columns.    But if I have a set of duplicate rows how do I / how does SQL Server decide which to remove? And how would I force it to remove all but the one with the highest IDENTITY value?  EMPLOYEE_ID     ATTENDANCE_DATE     AUTOID A001            2011-01-01          1 A001            2011-01-01          2   If I would run the query now it happens to remove the second one, with AUTOID 2. But I am trying to remove all but this one (because this is the one latest added). Ubuntu 14.04 System Logging I've set up an Ubuntu 14.04 Server (from an Ubuntu 12.04 Server) but today I wanted to look in the auth.log but this file is not used. It seems that ´syslog´ was deleted.  How does Ubuntu 14.04 log? I need this for a server.  Thank you. Just a quick question from an Objective-C beginner: what does the asterisk in the parenthesis mean in the following sample code? Is it a pointer? Thanks in advance.  #import &lt;Foundation/Foundation.h&gt;  @interface Tire : NSObject @end @implementation Tire  - (NSString *) description {    return (@"I am a tire."); }  @end Closed form for the sequence defined by $a_0=1$ and $a_{n+1} = a_n + a_n^{-1}$ What is the difference between g++ and gcc? Unitarily evolving a separable state into an entangled one How do I rename a domain and preserve SEO? Evaluating $\int_{-\infty}^{\infty}\frac{1}{(x^2+b^2)^2}dx$ Equation left margin Yesterday, Asaf Karagila's  sparked an extensive discussion on ways of proving that all countable ordinals are embeddable in $\Bbb Q$, and whether particular solutions to this use the Axiom of Choice.  Since the arguments used to prove this can be shady on their use of Choice when formulated tersely, fully fleshed out answers are appreciated.  To be concrete, this question asks for proofs of the following fact:     All countable ordinals $\alpha &lt; \omega_1$ are order-embeddable in the rationals $\Bbb Q$.   Especially answers avoiding the Axiom of Choice are appreciated.    Of relevance and related interest is  (but it's not a duplicate, since that question asks for explicit embeddings).