我在本地网络上使用 ssh 时遇到以下问题。
我使用 MAAS 设置了一个小型 Xeon 机器集群。我在所有机器上安装了 Ubuntu Server 12.04，并配置了本地网络 192.168.100.0/24。机器通过 TpLink TL-SG-1024 交换机连接。这些 Xeon 之间的 ssh 运行良好。
我已经将一些运行 Ubuntu 13.04 的 ARM 主板连接到此集群，但没有将它们添加到 MAAS。但是，我手动配置了 /etc/maas/dhcpd.conf，以便这些主板在同一本地网络 192.168.100.0/24 中获得固定 IP（v4）地址。主板获得相应的 IP，并且它们与每台 Xeon 机器之间的 ping 都有效。但是，ssh 不起作用 - 它挂起了。以下是ssh -vvv ubuntu@octa02（来自其中一台 Xeon 机器）的输出
OpenSSH_5.9p1 Debian-5ubuntu1.1, OpenSSL 1.0.1 14 Mar 2012
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to octa02 [192.168.100.82] port 22.
debug1: Connection established.
debug3: Incorrect RSA1 identifier
debug3: Could not load "/home/ubuntu/.ssh/id_rsa" as a RSA1 public key
debug1: identity file /home/ubuntu/.ssh/id_rsa type 1
debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048
debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048
debug1: identity file /home/ubuntu/.ssh/id_rsa-cert type -1
debug1: identity file /home/ubuntu/.ssh/id_dsa type -1
debug1: identity file /home/ubuntu/.ssh/id_dsa-cert type -1
debug1: identity file /home/ubuntu/.ssh/id_ecdsa type -1
debug1: identity file /home/ubuntu/.ssh/id_ecdsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.1p1 Debian-4
debug1: match: OpenSSH_6.1p1 Debian-4 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.9p1 Debian-5ubuntu1.1
debug2: fd 3 setting O_NONBLOCK
debug3: load_hostkeys: loading entries for host "octa02" from file "/home/ubuntu/.ssh/known_hosts"
debug3: load_hostkeys: found key type ECDSA in file /home/ubuntu/.ssh/known_hosts:15
debug3: load_hostkeys: loaded 1 keys
debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug1: SSH2_MSG_KEXINIT sent
当我尝试从 ARM 主板到 Xeon 主板的 ssh 时，也发生了同样的事情。唯一的区别是 ARM 主板上的 ssh 版本是：
OpenSSH_6.1p1 Debian-4, OpenSSL 1.0.1c 10 May 2012
因此，我在 ARM 上编译了 5.9 版本，结果是一样的。我也在 Xeon 上编译了 6.1 版本，它也挂了：
ssh -vvv ubuntu@octa02
OpenSSH_6.1p1, OpenSSL 1.0.1 14 Mar 2012
debug2: ssh_connect: needpriv 0
debug1: Connecting to 192.168.100.82 [192.168.100.82] port 22.
debug1: Connection established.
debug3: Incorrect RSA1 identifier
debug3: Could not load "/home/ubuntu/.ssh/id_rsa" as a RSA1 public key
debug1: identity file /home/ubuntu/.ssh/id_rsa type 1
debug1: identity file /home/ubuntu/.ssh/id_rsa-cert type -1
debug1: identity file /home/ubuntu/.ssh/id_dsa type -1
debug1: identity file /home/ubuntu/.ssh/id_dsa-cert type -1
debug1: identity file /home/ubuntu/.ssh/id_ecdsa type -1
debug1: identity file /home/ubuntu/.ssh/id_ecdsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_6.1p1 Debian-4
debug1: match: OpenSSH_6.1p1 Debian-4 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.1
debug2: fd 3 setting O_NONBLOCK
debug3: load_hostkeys: loading entries for host "192.168.100.82" from file "/home/ubuntu/.ssh/known_hosts"
debug3: load_hostkeys: loaded 0 keys
debug1: SSH2_MSG_KEXINIT sent
此外，ARM 主板之间的 ssh 6.1 可以正常工作。但是 ssh 6.1 到 ssh 5.9 不起作用。
最奇怪的是：我已将小板连接到外部网络。Xeon 集群主控也连接到此网络。主控和 ARM 板之间的 ssh 通过此网络工作（并且 ssh 有不同版本：Xeon 上的 5.9 和 ARM 上的 6.1）。
感谢您阅读这篇长文。您有什么建议吗？