# Error in deploy:setup concerning arcfour **URL:** \ **Category:** Deployment\ **Created:** [June 2, 2008, 12:12am UTC](https://www.ruby-forum.com/t/error-in-deploy-setup-concerning-arcfour/139217 "2008-06-02T00:12:30Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![ssmile](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/d6d6ee/32.png) [@ssmile](https://www.ruby-forum.com/u/ssmile)\ **Post date:** [June 2, 2008, 12:12am UTC](https://www.ruby-forum.com/t/error-in-deploy-setup-concerning-arcfour/139217/1 "2008-06-02T00:12:30Z")
Hi! I’m new to cap. When I execute cap deploy:setup, i am seeing arcfour error as: [root]# cap deploy:setup [DEPRECATION] Capistrano.configuration is deprecated. Use Capistrano::Configuration.instance instead - executing `deploy:setup’ - executing “umask 02 && mkdir -p /u/apps/ /u/apps// releases /u/apps//shared /u/apps//shared/system /u/apps/ /shared/log /u/apps//shared/pids” servers: [“localhost”] connection failed for: localhost (NotImplementedError: unsupported encryption algorithm: `arcfour’) And deploy.rb has role :web, “localhost” role :app, “localhost” role :db, “localhost”, :primary =\> true It is a linux system. Any suggesstion? Thanks! ---
**Author:** ![ssmile](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/d6d6ee/32.png) [@ssmile](https://www.ruby-forum.com/u/ssmile)\ **Post date:** [June 2, 2008, 8:19am UTC](https://www.ruby-forum.com/t/error-in-deploy-setup-concerning-arcfour/139217/2 "2008-06-02T08:19:12Z")
More information - when cap is attempting to connect net-ssh used is different for local and remote (wierd since both local and remote are the same system). Here it is: [root]# cap deploy:setup [DEPRECATION] Capistrano.configuration is deprecated. Use Capistrano::Configuration.instance instead - executing `deploy:setup’ - executing "umask 02 && mkdir - servers: [“uhostname”] D, [2008-06-01T23:12:12.009131 #17527] DEBUG – net.ssh.transport.session[…fdbfb7c00]: establishing connection to uhostname:22 D, [2008-06-01T23:12:12.024022 #17527] DEBUG – net.ssh.transport.session[…fdbfb7c00]: connection established I, [2008-06-01T23:12:12.024328 #17527] INFO – net.ssh.transport.server\_version[…fdbf3b1b0]: negotiating protocol version D, [2008-06-01T23:12:12.024466 #17527] DEBUG – net.ssh.transport.server\_version[…fdbf3b1b0]: remote is SSH-2.0- OpenSSH\_3.9p1 D, [2008-06-01T23:12:12.024543 #17527] DEBUG – net.ssh.transport.server\_version[…fdbf3b1b0]: local is SSH-2.0-Ruby/ Net::SSH\_2.0.2 i386-linux connection failed for: uhostname(NotImplementedError: unsupported encryption algorithm: `arcfour’) Why is the net.ssh.transport server\_version different for local and remote although both remote and local are the same system? How can I ensure that the remote system also uses the same net-ssh (both local and remote are physically the same box) Thanks! ---
**Author:** ![ssmile](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/d6d6ee/32.png) [@ssmile](https://www.ruby-forum.com/u/ssmile)\ **Post date:** [August 3, 2008, 4:46pm UTC](https://www.ruby-forum.com/t/error-in-deploy-setup-concerning-arcfour/139217/3 "2008-08-03T16:46:32Z")
> > - executing “umask 02 && mkdir -p /u/apps/ /u/apps// > > releases /u/apps//shared /u/apps//shared/system /u/apps/ > > /shared/log /u/apps//shared/pids” > > servers: [“localhost”] > > connection failed for: localhost (NotImplementedError: unsupported > > encryption algorithm: `arcfour’) Hey ssmile73, I had the same problem on my “CentOS release 5 (Final)” using ruby 1.8.6 and net-ssh 2.0.3 The problem is in net-ssh 2: irb(main):001:0\> require ‘rubygems’ ==\> true irb(main):002:0\> require ‘net/ssh’ ==\> true irb(main):003:0\> Net::SSH.start(‘[host.example.com](http://host.example.com)’, ‘user’) do | ssh | irb(main):004:1\* output = ssh.exec!(“hostname”) end NotImplementedError: unsupported encryption algorithm: `arcfour' from /usr/local/lib/ruby/gems/1.8/gems/net-ssh-2.0.3/lib/net/ ssh/transport/algorithms.rb:192:in `prepare\_preferred\_algorithms!’ from /usr/local/lib/ruby/gems/1.8/gems/net-ssh-2.0.3/lib/net/ ssh/transport/algorithms.rb:185:in `each' from /usr/local/lib/ruby/gems/1.8/gems/net-ssh-2.0.3/lib/net/ ssh/transport/algorithms.rb:185:in `prepare\_preferred\_algorithms!’ from /usr/local/lib/ruby/gems/1.8/gems/net-ssh-2.0.3/lib/net/ ssh/transport/algorithms.rb:96:in `initialize' from /usr/local/lib/ruby/gems/1.8/gems/net-ssh-2.0.3/lib/net/ ssh/transport/session.rb:77:in `new’ from /usr/local/lib/ruby/gems/1.8/gems/net-ssh-2.0.3/lib/net/ ssh/transport/session.rb:77:in `initialize' from /usr/local/lib/ruby/gems/1.8/gems/net-ssh-2.0.3/lib/net/ ssh.rb:182:in `new’ from /usr/local/lib/ruby/gems/1.8/gems/net-ssh-2.0.3/lib/net/ ssh.rb:182:in `start’ from (irb):3 When you look at line 192 in the algorithms.rb, it becomes clear that net-ssh is raising an error because the options it’s pulling out of your default config files (~/.ssh/config, /etc/ssh\_config, or /etc/ssh/ ssh\_config) don’t match what it expects. Specifically, one of your config files has a line “Ciphers” which has ‘arcfour’ listed amongst the available ciphers. The quickest way to get this working is to comment ‘#’ out the “Ciphers” line, or to remove the reference to ‘arcfour’ in it. I’m still looking at the code, but I think if the developers of net- ssh changed the line to skip if it can’t understand the option instead of raising an exception, that the module would still work, and you could specify whatever ciphers you wanted for your command-line ssh program without messing up your ruby net-ssh. I hope you haven’t been stuck on this for 2 months ☹ ## HTH donkeyfruit