: 시큐어 쉘로 접속하면 잘 되다가도
: 갑자기 다음과 같은 에러가 나타나면서 끊기곤 해요
:
: Hm, dispatch protocol error: type 20 plen 136
:
: 이게 무슨 의미고, 어떻게 의미를 해석해야 하죠?
:
: 꼭 좀 알려주세요
 www.openssh.com 의 FAQ에 보면 이 문제에 대해 나와있습니다:
 2.3 - Why does SSH 2.3 have problems interoperating with OpenSSH 2.1.1?
 SSH 2.3 and earlier versions contain a flaw in their HMAC implementation. Their code was not supplying the full data bl
ock output from the digest, and instead always provided 128 bits. For longer digests, this caused SSH 2.3 to not interop
erate with OpenSSH. OpenSSH 2.2.0 detects that SSH 2.3 has this flaw. Future versions of SSH will have this bug fixed. O
r you can add the following to ssh 2.3's /etc/sshd_config.  Mac hmac-md5   In addition to the flawed HMAC implementatio
n, problems in interoperation have been seen due to OpenSSH not yet supporting the option of rekeying. However SSH 2.3 t
ries to negotiate this feature, and you might experience connection freezes or see the error message "Dispatch protocol 
error: type 20". To solve this problem, either upgrade to SSH 2.4 or disable rekeying by adding the following to your co
mmercial SSH 2.3's sshd_config.  RekeyIntervalSeconds 0----;