Re: Quick SNMP Payload Structure Question

From: Eric Brandwine (ericbat_private)
Date: Wed Feb 27 2002 - 21:46:09 PST

  • Next message: BORBELY Zoltan: "Re: Quick SNMP Payload Structure Question"

    >>>>> "jk" == Jim Kovalchuk <raxorat_private> writes:
    
    jk> So you see most (valid) SNMP messages look something like: 
    jk> 30 2a 02 01 00 04 06 70 75 62 6c 69 63 . . . 
    
    jk> First byte is the tag byte, 30h stands for a sequence. 
    jk> Second byte is the length byte of the entire message.
    
    This is only true for messages that have a total length less than 128
    bytes.  Lengths longer than 128 bytes have to use the BER multibyte
    length encoding.  Most of the packets in the Oulu toolkit that have
    unfortunate effects on devices are much longer than 128 bytes.
    
    This is a well documented (if somewhat dense) standard.  Go to the
    official docs, rather than trying to reverse engineer it.  I've read
    the docs, and you'll never figure it out.  There's some odd stuff in
    BER.  That's why so many vendors have so much trouble decoding it
    safely.
    
    Don't waste your time picking the lock when someone hands you the key.
    
    ericb
    -- 
    Eric Brandwine     |  The difference between genius and stupidity is that
    UUNetwork Security |  genius has its limits. When you want to test the depths
    ericbat_private       |  of a stream, don't use both feet.
    +1 703 886 6038    |      - Chinese Proverb
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