build立
我们在办公室有一个DMZ和局域网，通过以下设置连接到外部：
+------+ | |------> LAN (normal office router) |Modem | | |------> DMZ (a single machine) +------+ 我们的互联网账号是Comcast，我们有5个状态IP，其中一个指向DMZ中的单机。
问题
ssh连接发起任何地方除了办公室局域网真的很快 。 但是，从局域网来看，大约有5秒钟的延迟。 WTF？
额外的信息
DMZ机是debian 5。
执行wget到DMZ没有滞后。
当执行以下任何操作时， HERE IS WHERE THE LAG IS INCURRED所有内容都是立即执行的。
ssh -vvvv [email protected] ... debug2: set_newkeys: mode 1 debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug3: Wrote 16 bytes for a total of 1015 debug2: set_newkeys: mode 0 debug1: SSH2_MSG_NEWKEYS received debug1: SSH2_MSG_SERVICE_REQUEST sent debug3: Wrote 48 bytes for a total of 1063 debug2: service_accept: ssh-userauth debug1: SSH2_MSG_SERVICE_ACCEPT received debug2: key: /home/shopkins/.ssh/id_rsa (0x22440830) debug2: key: /home/shopkins/.ssh/identity ((nil)) debug2: key: /home/shopkins/.ssh/id_dsa ((nil)) debug3: Wrote 64 bytes for a total of 1127` HERE IS WHERE THE LAG IS INCURRED debug1: Authentications that can continue: publickey,password debug3: start over, passed a different list publickey,password debug3: preferred gssapi-keyex,gssapi-with-mic,gssapi,publickey,keyboard-interactive,password debug3: authmethod_lookup publickey debug3: remaining preferred: keyboard-interactive,password debug3: authmethod_is_enabled publickey debug1: Next authentication method: publickey debug1: Offering public key: /home/shopkins/.ssh/id_rsa debug3: send_pubkey_test debug2: we sent a publickey packet, wait for reply debug3: Wrote 368 bytes for a total of 1495 debug1: Authentications that can continue: publickey,password debug1: Trying private key: /home/shopkins/.ssh/identity debug3: no such identity: /home/shopkins/.ssh/identity debug1: Trying private key: /home/shopkins/.ssh/id_dsa debug3: no such identity: /home/shopkins/.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:
最有可能不得不等待反向DNS查询超时/失败。
尝试在/ etc / ssh / sshd_config中设置 （假设你使用的是openssh的默认安装），看看是否解决了你的问题。
UseDNS no
您必须将"UseDNS no"添加到您尝试连接的目标主机上的/ etc / ssh / sshd_config文件中。
注意sshd_config和ssh_config之间的区别。
您必须重新启动目标主机上的ssh守护进程：
（对于FreeBSD）
/etc/rc.d/sshd restart