在Ubuntu上慢速连接上ssh

我最近在桌面上安装了Ubuntu 10.10作为第二个操作系统，但是我遇到一个奇怪的问题：通过ssh连接到其他Linux机器需要几十秒的时间。 在Windows上，我没有这样的问题，它立即连接。

所以，这不是一个主机有问题（即高负载），没有连接问题（即高延迟，丢包等）。 这个问题当然与客户及其连接时所采取的行动有关。

我怀疑这是与DNS /反向DNS相关的东西。 就像在等待我的IP上反向DNS获得连接之前，我不知道..

有谁知道如何解决这一问题？ 谢谢。

• 后缀和客户端IP反向DNS
• DNS推荐/授权：哪个DNS负责; 如何委托正确的方式？
• 电子邮件地址的语法是什么？ 在DNS区域文件中，SOA rr
• 通过一个固定的地址（例如IPv6）实现一个可以通过一个可变的IPv4地址连接的服务器？
• 你用什么服务来pipe理DNS？

稍后编辑：正如Jannebuild议的那样，我使用-vvv参数运行了命令。 输出是：

ssh -p 6969 -vvv [email protected] OpenSSH_5.5p1 Debian-4ubuntu4, OpenSSL 0.9.8o 01 Jun 2010 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug2: ssh_connect: needpriv 0 debug1: Connecting to myserver.mydomain.com [178.21.120.198] port 6969. debug1: Connection established. debug1: identity file /home/sorin/.ssh/id_rsa type -1 debug1: identity file /home/sorin/.ssh/id_rsa-cert type -1 debug1: identity file /home/sorin/.ssh/id_dsa type -1 debug1: identity file /home/sorin/.ssh/id_dsa-cert type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3 debug1: match: OpenSSH_4.3 pat OpenSSH_4* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.5p1 Debian-4ubuntu4 debug2: fd 3 setting O_NONBLOCK debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: [email protected],[email protected],ssh-rsa,ssh-dss debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected] debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected] debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,[email protected],zlib debug2: kex_parse_kexinit: none,[email protected],zlib debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: first_kex_follows 0 debug2: kex_parse_kexinit: reserved 0 debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 debug2: kex_parse_kexinit: ssh-rsa,ssh-dss debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,[email protected],aes128-ctr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,[email protected],aes128-ctr,aes192-ctr,aes256-ctr debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96 debug2: kex_parse_kexinit: none,[email protected] debug2: kex_parse_kexinit: none,[email protected] debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: debug2: kex_parse_kexinit: first_kex_follows 0 debug2: kex_parse_kexinit: reserved 0 debug2: mac_setup: found hmac-md5 debug1: kex: server->client aes128-ctr hmac-md5 none debug2: mac_setup: found hmac-md5 debug1: kex: client->server aes128-ctr hmac-md5 none debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP debug2: dh_gen_key: priv key bits set: 111/256 debug2: bits set: 534/1024 debug1: SSH2_MSG_KEX_DH_GEX_INIT sent debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY debug3: put_host_port: [178.21.120.198]:6969 debug3: put_host_port: [myserver.mydomain.com]:6969 debug3: check_host_in_hostfile: host [myserver.mydomain.com]:6969 filename /home/sorin/.ssh/known_hosts debug3: check_host_in_hostfile: host [myserver.mydomain.com]:6969 filename /home/sorin/.ssh/known_hosts debug3: check_host_in_hostfile: match line 1 debug3: check_host_in_hostfile: host [178.21.120.198]:6969 filename /home/sorin/.ssh/known_hosts debug3: check_host_in_hostfile: host [178.21.120.198]:6969 filename /home/sorin/.ssh/known_hosts debug3: check_host_in_hostfile: match line 2 debug1: Host '[myserver.mydomain.com]:6969' is known and matches the RSA host key. debug1: Found key in /home/sorin/.ssh/known_hosts:1 debug2: bits set: 491/1024 debug1: ssh_rsa_verify: signature correct debug2: kex_derive_keys debug2: set_newkeys: mode 1 debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug2: set_newkeys: mode 0 debug1: SSH2_MSG_NEWKEYS received debug1: Roaming not allowed by server debug1: SSH2_MSG_SERVICE_REQUEST sent debug2: service_accept: ssh-userauth debug1: SSH2_MSG_SERVICE_ACCEPT received debug2: key: /home/sorin/.ssh/id_rsa ((nil)) debug2: key: /home/sorin/.ssh/id_dsa ((nil)) debug1: Authentications that can continue: publickey,gssapi-with-mic,password debug3: start over, passed a different list publickey,gssapi-with-mic,password debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive,password debug3: authmethod_lookup gssapi-with-mic debug3: remaining preferred: publickey,keyboard-interactive,password debug3: authmethod_is_enabled gssapi-with-mic debug1: Next authentication method: gssapi-with-mic debug1: Unspecified GSS failure. Minor code may provide more information Credentials cache file '/tmp/krb5cc_1000' not found debug1: Unspecified GSS failure. Minor code may provide more information Credentials cache file '/tmp/krb5cc_1000' not found debug1: Unspecified GSS failure. Minor code may provide more information debug2: we did not send a packet, disable method debug3: authmethod_lookup publickey debug3: remaining preferred: keyboard-interactive,password debug3: authmethod_is_enabled publickey debug1: Next authentication method: publickey debug1: Trying private key: /home/sorin/.ssh/id_rsa debug3: no such identity: /home/sorin/.ssh/id_rsa debug1: Trying private key: /home/sorin/.ssh/id_dsa debug3: no such identity: /home/sorin/.ssh/id_dsa debug2: we did not send a packet, disable method debug3: authmethod_lookup password debug3: remaining preferred: ,password debug3: authmethod_is_enabled password debug1: Next authentication method: password [email protected]'s password: 

出于安全原因，我用myserver和myserver.mydomain.comreplace了用户名。

 ssh -vvv user@host 2> >(ts) 

 -o PreferredAuthentications=hostbased,publickey,keyboard-interactive,password