1、现象： 使用crt连接服务器的速度很慢， 使用putty连接的速度却很快
2、解决思路：
打开securecrt的file--->trace options，点选后， 直接连接服务器，查看输出的trace信息，
可以看到如下信息：
[PRINTER] : Printer initialization succeeded [LOCAL] : SSH2Core version 8.5.0.1867 [LOCAL] : Connecting to 192.168.18.131:22 ... [LOCAL] : Changing state from STATE_NOT_CONNECTED to STATE_EXPECT_KEX_INIT [LOCAL] : Using protocol SSH2 [LOCAL] : RECV : Remote Identifier = 'SSH-2.0-OpenSSH_6.6.1' [LOCAL] : CAP : Remote can re-key [LOCAL] : CAP : Remote sends language in password change requests [LOCAL] : CAP : Remote sends algorithm name in PK_OK packets [LOCAL] : CAP : Remote sends algorithm name in public key packets [LOCAL] : CAP : Remote sends algorithm name in signatures [LOCAL] : CAP : Remote sends error text in open failure packets [LOCAL] : CAP : Remote sends name in service accept packets [LOCAL] : CAP : Remote includes port number in x11 open packets [LOCAL] : CAP : Remote uses 160 bit keys for SHA1 MAC [LOCAL] : CAP : Remote supports new diffie-hellman group exchange messages [LOCAL] : CAP : Remote correctly handles unknown SFTP extensions [LOCAL] : CAP : Remote correctly encodes OID for gssapi [LOCAL] : CAP : Remote correctly uses connected addresses in forwarded-tcpip requests [LOCAL] : CAP : Remote can do SFTP version 4 [LOCAL] : CAP : Remote uses SHA1 hash in RSA signatures for x.509v3 [LOCAL] : CAP : Remote x.509v3 uses ASN.1 encoding for DSA signatures [LOCAL] : CAP : Remote correctly handles zlib@openssh.com [LOCAL] : SEND : KEXINIT [LOCAL] : RECV : Read kexinit [LOCAL] : Available Remote Kex Methods = curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1 [LOCAL] : Selected Kex Method = curve25519-sha256@libssh.org [LOCAL] : Available Remote Host Key Algos = ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519 [LOCAL] : Selected Host Key Algo = ssh-rsa [LOCAL] : Available Remote Send Ciphers = aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se [LOCAL] : Selected Send Cipher = aes256-ctr [LOCAL] : Available Remote Recv Ciphers = aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-gcm@openssh.com,aes256-gcm@openssh.com,chacha20-poly1305@openssh.com,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se [LOCAL] : Selected Recv Cipher = aes256-ctr [LOCAL] : Available Remote Send Macs = hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96 [LOCAL] : Selected Send Mac = hmac-sha2-512 [LOCAL] : Available Remote Recv Macs = hmac-md5-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-md5,hmac-sha1,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96 [LOCAL] : Selected Recv Mac = hmac-sha2-512 [LOCAL] : Available Remote Compressors = none,zlib@openssh.com [LOCAL] : Selected Compressor = none [LOCAL] : Available Remote Decompressors = none,zlib@openssh.com [LOCAL] : Selected Decompressor = none [LOCAL] : Changing state from STATE_EXPECT_KEX_INIT to STATE_KEY_EXCHANGE [LOCAL] : SEND : SSH_MSG_KEX_ECDH_INIT [LOCAL] : RECV : SSH_MSG_KEX_ECDH_REPLY [LOCAL] : Changing state from STATE_KEY_EXCHANGE to STATE_READY_FOR_NEW_KEYS [LOCAL] : RECV: Remote Hostkey (SHA-2 hash hex): a6:3b:be:e3:1a:41:d0:65:77:af:0b:5a:c8:75:8c:03:19:e7:ad:4d:d1:e7:a1:d7:9b:43:8e:ac:f4:70:e1:3e [LOCAL] : RECV: Remote Hostkey (SHA-2 hash base64): pju+4xpB0GV3rwtayHWMAxnnrU3R56HXm0OOrPRw4T4 [LOCAL] : RECV: Remote Hostkey (SHA-1 hash): f1:e2:35:d1:22:a5:7f:87:fb:4e:05:cc:35:10:d2:63:93:6d:84:49 [LOCAL] : RECV: Remote Hostkey (MD5 hash): fd:6a:16:b3:66:39:eb:97:26:c0:34:b5:de:56:1e:3e [LOCAL] : SEND : NEWKEYS [LOCAL] : Changing state from STATE_READY_FOR_NEW_KEYS to STATE_EXPECT_NEWKEYS [LOCAL] : RECV : NEWKEYS [LOCAL] : Changing state from STATE_EXPECT_NEWKEYS to STATE_CONNECTION [LOCAL] : SEND: SERVICE_REQUEST[ssh-userauth] [LOCAL] : RECV: SERVICE_ACCEPT[ssh-userauth] -- OK [LOCAL] : SENT : USERAUTH_REQUEST [none] [LOCAL] : Authenticating as user rhce [LOCAL] : RECV : USERAUTH_FAILURE, continuations [publickey,gssapi-keyex,gssapi-with-mic,password] [LOCAL] : SENT : USERAUTH_REQUEST [password] [LOCAL] : RECV : AUTH_SUCCESS [LOCAL] : SEND[0]: SSH_MSG_CHANNEL_OPEN('session') SecureCRT - Version 8.5.3 (x64 build 1867) [LOCAL] : SEND[0]: Pty Request (rows: 30, cols: 105) [LOCAL] : RECV[0]: pty request succeeded [LOCAL] : SEND[0]: shell request [LOCAL] : RECV[0]: shell request succeeded
3、分析
可以看到有很多的 key exchange method是不支持的， 所以要尽快的连接，需要将不支持的选项禁用（此处没有过多的深入研究，如何支持这些报错的 key exchange method），如下图：
全局（all sessions）后重启crt，即可以实现快速连接。问题得到解决。
有时间的朋友可以去研究下如何支持报错的key change method
