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7. Message Numbers

  1. Message Numbers

SSH packets have message numbers in the range 1 to 255. These numbers have been allocated as follows:

Transport layer protocol:

1 to 19 Transport layer generic (e.g., disconnect, ignore, debug, etc.) 20 to 29 Algorithm negotiation 30 to 49 Key exchange method specific (numbers can be reused for different authentication methods)

User authentication protocol:

50 to 59 User authentication generic 60 to 79 User authentication method specific (numbers can be reused for different authentication methods)

RFC 4251 SSH Protocol Architecture January 2006

Connection protocol:

80 to 89 Connection protocol generic 90 to 127 Channel related messages

Reserved for client protocols:

128 to 191 Reserved

Local extensions:

192 to 255 Local extensions

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