Solve the problem that BT5 cannot use putty to connect

Root @ bt:/etc/ssh # sshd-generate
Generating public/private rsa1 key pair.
/Etc/ssh/ssh_host_key already exists.
Overwrite (y/n )? Y
Your identification has been saved in/etc/ssh/ssh_host_key.
Your public key has been saved in/etc/ssh/ssh_host_key.pub.
The key fingerprint is:
31: ce: fd: 3f: a9: 5e: f5: b0: c0: 88: 99: 3c: a7: 06: 31: 5c root @ bt
The keys randomart image is:
+ -- [RSA1 2048] ---- +
| E |
|... |
| + O |
| * B o |
|. S + o... |
|. +... +. |
| O. o .. |
|. Oo |
|. O... |
+ ----------------- +
Generating public/private rsa key pair.
/Etc/ssh/ssh_host_rsa_key already exists.
Overwrite (y/n )? Y
Your identification has been saved in/etc/ssh/ssh_host_rsa_key.
Your public key has been saved in/etc/ssh/ssh_host_rsa_key.pub.
The key fingerprint is:
B4: 09: bd: 9d: 1c: 20: 8e: 45: f1: 25: 32: cb: 69: 95: fe: 2e root @ bt
The keys randomart image is:
+ -- [RSA 2048] ---- +
|. B. +... |
| = X. + |
|. B. +. |
|. O. * o |
| S. + |
|. |
|. |
| E. |
|. |
+ ----------------- +
Generating public/private dsa key pair.
/Etc/ssh/ssh_host_dsa_key already exists.
Overwrite (y/n )? Y
Your identification has been saved in/etc/ssh/ssh_host_dsa_key.
Your public key has been saved in/etc/ssh/ssh_host_dsa_key.pub.
The key fingerprint is:
C8: 8e: b6: 24: c3: a1: e2: 65: fa: b0: c4: 45: 27: ba: ef: c6 root @ bt
The keys randomart image is:
+ -- [DSA 1024] ---- +
|
|
| O. |
| O .. |
|... O S |
|. Oo. o |
| O = o +. |
| + BE. |
| ++. |
+ ----------------- +
Root @ bt:/etc/ssh #/etc/init. d/ssh start
* Starting OpenBSD Secure Shell server sshd [OK]