最近突然一下想研究（折腾）一下freebsd，于是在vbox里装了一个freebsd，没有图形界面的操作系统总是吃很少的资源。但是
- 字符界面的颜色不好看
- 切换虚拟机不方便
于是我自然想到用自己的终端通过ssh连接到虚拟机，总有一些想尝试linux的同学，徘徊在双系统和虚拟机中。我的建议是，装服务器版的Linux发行版到虚拟机中，然后通过xshell登陆到自己的虚拟机，这才是最专业的做法 :)。
首先装机,一般服务器版都是没有图形界面的，分配128m内存足够了，我给我的分配了512m的内存（因为我有的时候利用ports直接源码安装，即使是这样也足够了）。
首先在虚拟机中ping一下看连上网没有，如果没有连上网，ssh无法访问：）
vbox创建时的网络选取的是NAT连接（网络地址转换），所以我们只需要改变端口就可以了，我们可以将自己主机的端口映射到22端口上（ssh默认22端口），这样我们可以访问localhost就能连上虚拟机了。
如果你的2222端口没有被占用的化，这样就设置好了。
然后设置服务器的sshd服务，一般都会自带，如果没有的话可以用包管理器安装 然后启动的服务
/etc/init.d/sshd start
下面是我的sshd_config的配置，可以进行适当修改
# $OpenBSD: sshd_config,v 1.98 2016/02/17 05:29:04 djm Exp $
# $FreeBSD: releng/10.3/crypto/openssh/sshd_config 296853 2016-03-14 13:05:13Z des $
# This is the sshd server system-wide configuration file. See
# sshd_config(5) for more information.
# This sshd was compiled with PATH=/usr/bin:/bin:/usr/sbin:/sbin
# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented. Uncommented options override the
# default value.
# Note that some of FreeBSD's defaults differ from OpenBSD's, and
# FreeBSD has a few additional options.
#Port 22
#AddressFamily any
#ListenAddress 0.0.0.0
#ListenAddress ::
# The default requires explicit activation of protocol 1
#Protocol 2
# HostKey for protocol version 1
#HostKey /etc/ssh/ssh_host_key
# HostKeys for protocol version 2
#HostKey /etc/ssh/ssh_host_rsa_key
#HostKey /etc/ssh/ssh_host_dsa_key
#HostKey /etc/ssh/ssh_host_ecdsa_key
#HostKey /etc/ssh/ssh_host_ed25519_key
# Lifetime and size of ephemeral version 1 server key
#KeyRegenerationInterval 1h
#ServerKeyBits 1024
# Ciphers and keying
#RekeyLimit default none
# Logging
# obsoletes QuietMode and FascistLogging
#SyslogFacility AUTH
#LogLevel INFO
# Authentication:
#LoginGraceTime 2m
PermitRootLogin no
StrictModes no
#MaxAuthTries 6
#MaxSessions 10
RSAAuthentication yes
#PubkeyAuthentication yes
# The default is to check both .ssh/authorized_keys and .ssh/authorized_keys2
#AuthorizedKeysFile .ssh/authorized_keys .ssh/authorized_keys2
#AuthorizedPrincipalsFile none
#AuthorizedKeysCommand none
#AuthorizedKeysCommandUser nobody
# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
#RhostsRSAAuthentication no
# similar for protocol version 2
#HostbasedAuthentication no
# Change to yes if you don't trust ~/.ssh/known_hosts for
# RhostsRSAAuthentication and HostbasedAuthentication
IgnoreUserKnownHosts yes
# Don't read the user's ~/.rhosts and ~/.shosts files
IgnoreRhosts yes
# Change to yes to enable built-in password authentication.
PasswordAuthentication yes
PermitEmptyPasswords no
# Change to no to disable PAM authentication
#ChallengeResponseAuthentication yes
# Kerberos options
#KerberosAuthentication no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes
#KerberosGetAFSToken no
# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes
# Set this to 'no' to disable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the ChallengeResponseAuthentication and
# PasswordAuthentication. Depending on your PAM configuration,
# PAM authentication via ChallengeResponseAuthentication may bypass
# the setting of "PermitRootLogin without-password".
# If you just want the PAM account and session checks to run without
# PAM authentication, then enable this but set PasswordAuthentication
# and ChallengeResponseAuthentication to 'no'.
#UsePAM yes
#AllowAgentForwarding yes
#AllowTcpForwarding yes
#GatewayPorts no
#X11Forwarding yes
#X11DisplayOffset 10
#X11UseLocalhost yes
#PermitTTY yes
PrintMotd yes
#PrintLastLog yes
#TCPKeepAlive yes
#UseLogin no
#UsePrivilegeSeparation sandbox
#PermitUserEnvironment no
#Compression delayed
#ClientAliveInterval 0
#ClientAliveCountMax 3
#UseDNS yes
#PidFile /var/run/sshd.pid
#MaxStartups 10:30:100
#PermitTunnel no
#ChrootDirectory none
#VersionAddendum FreeBSD-20160310
# no default banner path
#Banner none
# override default of no subsystems
Subsystem sftp /usr/libexec/sftp-server
# Example of overriding settings on a per-user basis
#Match User anoncvs
# X11Forwarding no
# AllowTcpForwarding no
# PermitTTY no
# ForceCommand cvs server
然后输入ssh -p 2222 YOURNAME@127.0.0.1
YOURNAME 指的是你自己的用户名，这样就可以登陆上去了cheers～
