SPAP decode help - PPP

This is a discussion on SPAP decode help - PPP ; Could anybody offer some advice on decoding the following PPP SPAP Auth message sequence (i've skipped the surrounding info that's in the LCP messages): LCP Conf Request: Authentication protocol SPAP (0xC027), Data (8 bytes) 01 00 00 03 00 00 ...

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Thread: SPAP decode help

  1. SPAP decode help

    Could anybody offer some advice on decoding the following PPP SPAP Auth
    message sequence (i've skipped the surrounding info that's in the LCP
    messages):

    LCP Conf Request: Authentication protocol SPAP (0xC027), Data (8 bytes) 01
    00 00 03 00 00 00 0E
    LCP NAK: Authentication Protocol SPAP (0xC027), data (4 bytes) 01 00 00 01
    LCP Conf Request: Authentication Protocol SPAP (0xC027), data (4 bytes) 01
    00 00 01
    LCP Conf Ack: Authentication Protocol SPAP (0xC027), data (4 bytes) 01 00
    00 01

    The above sequence clearly negotiates the SPAP data to 01 00 00 01.
    However, could somebody tell me the format/meaning of the data field for
    SPAP. This connection sequence succesfully negotiates a connection from Win
    2000 to shiva server.

    I have a another dial up client which is using SPAP that is refusing to
    negotiate to 01 00 00 01 and hence is failing to connect using the servers
    offered data of 01 00 00 03 00 00 00 0E. This client is actually a Shiva
    and the server is a Shiva so this is the config that should be easy to make
    work ! However, I have no knowledge of how the server is set up so I'm
    trying to deduce the settings I need to make on the Shiva client by
    analysing the working connection as shown in the trace above.

    Anybody point me to SPAP option definition ?

    Thanks,

    jed

  2. Re: SPAP decode help

    Jed wrote:
    > Could anybody offer some advice on decoding the following PPP SPAP Auth
    > message sequence (i've skipped the surrounding info that's in the LCP
    > messages):


    > LCP Conf Request: Authentication protocol SPAP (0xC027), Data (8 bytes) 01
    > 00 00 03 00 00 00 0E
    > LCP NAK: Authentication Protocol SPAP (0xC027), data (4 bytes) 01 00 00 01
    > LCP Conf Request: Authentication Protocol SPAP (0xC027), data (4 bytes) 01
    > 00 00 01
    > LCP Conf Ack: Authentication Protocol SPAP (0xC027), data (4 bytes) 01 00
    > 00 01


    > The above sequence clearly negotiates the SPAP data to 01 00 00 01.
    > However, could somebody tell me the format/meaning of the data
    > field for SPAP. This connection sequence succesfully negotiates a
    > connection from Win 2000 to shiva server.


    SPAP is not published by Shiva, so it's likely that only a Shiva PPP
    implementor could tell you - but unlikely that any would do so.

    > I have a another dial up client which is using SPAP that is refusing to
    > negotiate to 01 00 00 01 and hence is failing to connect using the servers
    > offered data of 01 00 00 03 00 00 00 0E. This client is actually a Shiva
    > and the server is a Shiva so this is the config that should be easy to make
    > work ! However, I have no knowledge of how the server is set up so I'm
    > trying to deduce the settings I need to make on the Shiva client by
    > analysing the working connection as shown in the trace above.


    The Shiva client might be using an outdated SPAP implementation relative
    to the server implementation and send a Code-Rej or Conf-Rej, either
    of which would cause negotiation failure. To the best of my (meager)
    knowledge SPAP has only 4 data octets for negotiation, but that could
    have changed. The message exchanges above suggest that it did change.

    > Anybody point me to SPAP option definition ?


    I'd think there would be documentation for configuring the client SPAP.
    If there is none then that would seem to support the conjecture that
    it's SPAP implementation is outdated.

    -- Clifford Kite mail: "echo xvgr_yvahk-ccc@ri1.arg|rot13"
    PPP-Q&A links, downloads: http://ckite.no-ip.net/
    /* Slogan appropriate for a certain well-known software company:
    FAILURE IS NOT AN OPTION - it is built into the operating system
    and comes bundled with the software. */

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