problems with huawei E3372 alias Telekom Speedstick V

Bjørn Mork bjorn at mork.no
Sun Oct 19 05:50:25 PDT 2014


Thomas Schäfer <tschaefer at t-online.de> writes:

> Am Montag, 1. September 2014, 10:59:55 schrieb Bjørn Mork:
>
>> Well, the thing I note with MBIM dissection enabled (which also does NCM
>> quite nicely) is that Windows use 32bit NCM headers while we use 16bit.
>> The 'ncmh' vs 'NCMH' signature difference you know from the last time I
>> messed up the NCM driver :-)
>
> I switched off 32-bit in windows (driver properties in device manager). It 
> still works there.
> May be there are some other things different.
>
> Attached (link) is the windows version.

I started an attempt to compare this step by step with the Linux dump
you've provided before.  Both management applications issue a number of
AT commands prior to connecting, making sure everything is set up OK
etc.  Which looks fine.  But when I got to the connect phase there is a
striking difference:  I cannot find any AT^NDISCONN or AT^NDISDUP
command at all in the Linux dump.  Why is that?  Was it sent on another
port?  I can see that "something" triggered a connection, because the
unsolicted(?) ^NDISSTATQRY goes from 0 to 1, and there is also a

 ^NDISSTAT:1,,,"IPV4"

report. But looking at the Linux dump (e3372-linux.pcapng.7z) again now
I noticed something very odd: The modem seems to send ARP requests to
the host *before* the host sends any DHCP requests.  I don't remeber if
we touched this issue the last time we discussed this modem?  In any
case, I find this odd and unexpected.  Maybe the modem believes you have
requested and got the address using some other facility (like AT^DHCP)?

Specifically, this ARP request from the modem:

Frame 1353: 
..
Mobile Broadband Interface Model
    NCM Transfer Header
        Signature: NCMH
        Header Length: 12
        Sequence Number: 0
        Block Length: 94
        NDP Index: 12
    NCM Datagram Pointer
        Signature: NCM0
        Length: 16
        Next NDP Index: 0
        Datagram Index: 30
        Datagram Length: 60
        Datagram: ffffffffffff4c549945e5d5080600010800060400014c54...
        Datagram Index: 0
        Datagram Length: 0
        [Number Of Datagrams: 1]
    [Total Number Of Datagrams: 1]
Ethernet II, Src: 4c:54:99:45:e5:d5 (4c:54:99:45:e5:d5), Dst: ff:ff:ff:ff:ff:ff (ff:ff:ff:ff:ff:ff)
    Destination: ff:ff:ff:ff:ff:ff (ff:ff:ff:ff:ff:ff)
        Address: ff:ff:ff:ff:ff:ff (ff:ff:ff:ff:ff:ff)
        .... ..1. .... .... .... .... = LG bit: Locally administered address (this is NOT the factory default)
        .... ...1 .... .... .... .... = IG bit: Group address (multicast/broadcast)
    Source: 4c:54:99:45:e5:d5 (4c:54:99:45:e5:d5)
        Address: 4c:54:99:45:e5:d5 (4c:54:99:45:e5:d5)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
    Type: ARP (0x0806)
    Trailer: 000000000000000000000000000000000000
Address Resolution Protocol (request)
    Hardware type: Ethernet (1)
    Protocol type: IP (0x0800)
    Hardware size: 6
    Protocol size: 4
    Opcode: request (1)
    Sender MAC address: 4c:54:99:45:e5:d5 (4c:54:99:45:e5:d5)
    Sender IP address: 10.76.183.166 (10.76.183.166)
    Target MAC address: 00:00:00:00:00:00 (00:00:00:00:00:00)
    Target IP address: 10.76.183.165 (10.76.183.165)

0000  c0 1a 03 31 00 88 ff ff 43 03 85 04 01 00 2d 00   ...1....C.....-.
0010  48 17 02 54 00 00 00 00 a7 6f 05 00 00 00 00 00   H..T.....o......
0020  5e 00 00 00 5e 00 00 00 00 00 00 00 00 00 00 00   ^...^...........
0030  00 00 00 00 00 00 00 00 00 02 00 00 00 00 00 00   ................
0040  4e 43 4d 48 0c 00 00 00 5e 00 0c 00 4e 43 4d 30   NCMH....^...NCM0
0050  10 00 00 00 1e 00 3c 00 00 00 00 00 00 00 ff ff   ......<.........
0060  ff ff ff ff 4c 54 99 45 e5 d5 08 06 00 01 08 00   ....LT.E........
0070  06 04 00 01 4c 54 99 45 e5 d5 0a 4c b7 a6 00 00   ....LT.E...L....
0080  00 00 00 00 0a 4c b7 a5 00 00 00 00 00 00 00 00   .....L..........
0090  00 00 00 00 00 00 00 00 00 00 00 00 00 00         ..............


before this DHCP request from the host:


Frame 1397: 
..
Mobile Broadband Interface Model
    NCM Transfer Header
        Signature: NCMH
        Header Length: 12
        Sequence Number: 3
        Block Length: 526
        NDP Index: 12
    NCM Datagram Pointer
        Signature: NCM0
        Length: 16
        Next NDP Index: 0
        Datagram Index: 184
        Datagram Length: 342
        Datagram: ffffffffffff001e101f0000080045100148000000008011...
        Datagram Index: 0
        Datagram Length: 0
        [Number Of Datagrams: 1]
    [Total Number Of Datagrams: 1]
Ethernet II, Src: 00:1e:10:1f:00:00 (00:1e:10:1f:00:00), Dst: ff:ff:ff:ff:ff:ff (ff:ff:ff:ff:ff:ff)
    Destination: ff:ff:ff:ff:ff:ff (ff:ff:ff:ff:ff:ff)
        Address: ff:ff:ff:ff:ff:ff (ff:ff:ff:ff:ff:ff)
        .... ..1. .... .... .... .... = LG bit: Locally administered address (this is NOT the factory default)
        .... ...1 .... .... .... .... = IG bit: Group address (multicast/broadcast)
    Source: 00:1e:10:1f:00:00 (00:1e:10:1f:00:00)
        Address: 00:1e:10:1f:00:00 (00:1e:10:1f:00:00)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
    Type: IP (0x0800)
Internet Protocol Version 4, Src: 0.0.0.0 (0.0.0.0), Dst: 255.255.255.255 (255.255.255.255)
    Version: 4
    Header Length: 20 bytes
    Differentiated Services Field: 0x10 (DSCP 0x04: Unknown DSCP; ECN: 0x00: Not-ECT (Not ECN-Capable Transport))
        0001 00.. = Differentiated Services Codepoint: Unknown (0x04)
        .... ..00 = Explicit Congestion Notification: Not-ECT (Not ECN-Capable Transport) (0x00)
    Total Length: 328
    Identification: 0x0000 (0)
    Flags: 0x00
        0... .... = Reserved bit: Not set
        .0.. .... = Don't fragment: Not set
        ..0. .... = More fragments: Not set
    Fragment offset: 0
    Time to live: 128
    Protocol: UDP (17)
    Header checksum: 0x3996 [validation disabled]
        [Good: False]
        [Bad: False]
    Source: 0.0.0.0 (0.0.0.0)
    Destination: 255.255.255.255 (255.255.255.255)
    [Source GeoIP: Unknown]
    [Destination GeoIP: Unknown]
User Datagram Protocol, Src Port: 68 (68), Dst Port: 67 (67)
    Source Port: 68 (68)
    Destination Port: 67 (67)
    Length: 308
    Checksum: 0x9c4a [correct]
        [Calculated Checksum: 0x9c4a]
        [Good Checksum: True]
        [Bad Checksum: False]
    [Stream index: 0]
Bootstrap Protocol (Discover)
    Message type: Boot Request (1)
    Hardware type: Ethernet (0x01)
    Hardware address length: 6
    Hops: 0
    Transaction ID: 0xe7db064a
    Seconds elapsed: 0
    Bootp flags: 0x0000 (Unicast)
        0... .... .... .... = Broadcast flag: Unicast
        .000 0000 0000 0000 = Reserved flags: 0x0000
    Client IP address: 0.0.0.0 (0.0.0.0)
    Your (client) IP address: 0.0.0.0 (0.0.0.0)
    Next server IP address: 0.0.0.0 (0.0.0.0)
    Relay agent IP address: 0.0.0.0 (0.0.0.0)
    Client MAC address: 00:1e:10:1f:00:00 (00:1e:10:1f:00:00)
    Client hardware address padding: 00000000000000000000
    Server host name not given
    Boot file name not given
    Magic cookie: DHCP
    Option: (53) DHCP Message Type (Discover)
        Length: 1
        DHCP: Discover (1)
    Option: (50) Requested IP Address
        Length: 4
        Requested IP Address: 192.168.8.101 (192.168.8.101)
    Option: (55) Parameter Request List
        Length: 19
        Parameter Request List Item: (1) Subnet Mask
        Parameter Request List Item: (28) Broadcast Address
        Parameter Request List Item: (3) Router
        Parameter Request List Item: (121) Classless Static Route
        Parameter Request List Item: (26) Interface MTU
        Parameter Request List Item: (12) Host Name
        Parameter Request List Item: (15) Domain Name
        Parameter Request List Item: (119) Domain Search
        Parameter Request List Item: (6) Domain Name Server
        Parameter Request List Item: (40) Network Information Service Domain
        Parameter Request List Item: (41) Network Information Service Servers
        Parameter Request List Item: (87) Novell Directory Services Context
        Parameter Request List Item: (85) Novell Directory Services Servers
        Parameter Request List Item: (86) Novell Directory Services Tree Name
        Parameter Request List Item: (44) NetBIOS over TCP/IP Name Server
        Parameter Request List Item: (45) NetBIOS over TCP/IP Datagram Distribution Name Server
        Parameter Request List Item: (46) NetBIOS over TCP/IP Node Type
        Parameter Request List Item: (47) NetBIOS over TCP/IP Scope
        Parameter Request List Item: (42) Network Time Protocol Servers
    Option: (255) End
        Option End: 255
    Padding

0000  00 2a a1 59 00 88 ff ff 53 03 04 04 01 00 2d 00   .*.Y....S.....-.
0010  49 17 02 54 00 00 00 00 b1 fb 05 00 8d ff ff ff   I..T............
0020  0e 02 00 00 0e 02 00 00 00 00 00 00 00 00 00 00   ................
0030  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
0040  4e 43 4d 48 0c 00 03 00 0e 02 0c 00 4e 43 4d 30   NCMH........NCM0
0050  10 00 00 00 b8 00 56 01 00 00 00 00 00 00 00 00   ......V.........
0060  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
0070  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
0080  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
0090  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
00a0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
00b0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
00c0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
00d0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
00e0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
00f0  00 00 00 00 00 00 00 00 ff ff ff ff ff ff 00 1e   ................
0100  10 1f 00 00 08 00 45 10 01 48 00 00 00 00 80 11   ......E..H......
0110  39 96 00 00 00 00 ff ff ff ff 00 44 00 43 01 34   9..........D.C.4
0120  9c 4a 01 01 06 00 e7 db 06 4a 00 00 00 00 00 00   .J.......J......
0130  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 1e   ................
0140  10 1f 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
0150  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
0160  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
0170  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
0180  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
0190  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
01a0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
01b0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
01c0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
01d0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
01e0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
01f0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
0200  00 00 00 00 00 00 00 00 00 00 00 00 00 00 63 82   ..............c.
0210  53 63 35 01 01 32 04 c0 a8 08 65 37 13 01 1c 03   Sc5..2....e7....
0220  79 1a 0c 0f 77 06 28 29 57 55 56 2c 2d 2e 2f 2a   y...w.()WUV,-./*
0230  ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
0240  00 00 00 00 00 00 00 00 00 00 00 00 00 00         ..............


is odd.  And the modem continues to send us these ARP requests.  So it
does look like it expects static addressing here?  In any case, the ARP
requests do get through just fine, with proper 16bit headers, so I don't
know what I was worrying about before.  They show clearly that we do
have ethernet frames flowing from the modem to host.  We just cannot get
IP working for some reason.  Which must then be a mere addressing thing
AFAICS.



Bjørn


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