[ubuntu] Problema XDMCP

[andrew1988]

Ho configurato il mio notebook per un login remoto via xdmcp, ma quando da un altro pc connesso in lan tento di connettermi inserisco l'IP del notebook, lo trova (dicendo anche la versione del kernel..), connetto e compare una schermata nera con una X (nera con bordo bianco) come puntatore senza chiedermi un login.... l'unico modo e' ctrl+alt+backspace x tornare al menu' d login locale.... sbaglio a settare qualcosa sul server?? come lo risolvo sto problemino stupido???

[sacarde]

riguarda la configurazione di xdmcp


...
...
Per ragioni di sicurezza, X Display Manager Control Protocol è configurato di default (come impostazione predefinita) per rifiutare le connessioni remote delle workstation. Questa è, in genere, la causa del comune problema di vedere soltanto una schermata nera con una cursore a forma di X
...
...

[andrew1988]

esatto.. infatti io in login windows preferences ho settato
--nel tab remote style: same as local;
--in security ho attivato: allow local system admin login, allow remote system admin login, enable debug...;
--nel tab users ho incluso il mio account e uno creato apposta x il remoto e in escludi ho lasciato nobody;

ho poi osservato che quella X compare anche durante una normale accensione, prima che appaia la schermata d login (welcome theme x intenderci), per circa mezzo secondo..

ho appena provato a includere la porta 177 nelle policy d allow d firestarter.. ma uguale a prima..

[andrew1988]

ho appena analizzato le connessioni XDMCP nel notebook con wireshark e si presenta la situazione del tipo... il client fa la request, server accetta, e il client va in stato di manage continuo... d seguito il codice

No.     Time        Source                Destination           Protocol Info
      3 27.491127   192.168.1.7           192.168.1.255         XDMCP    Broadcast_query

Frame 3 (60 bytes on wire, 60 bytes captured)
Ethernet II, Src: AsustekC_be:ae:ed (00:17:31:be:ae:ed), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol, Src: 192.168.1.7 (192.168.1.7), Dst: 192.168.1.255 (192.168.1.255)
User Datagram Protocol, Src Port: 53323 (53323), Dst Port: xdmcp (177)
    Source port: 53323 (53323)
    Destination port: xdmcp (177)
    Length: 16
    Checksum: 0xaa77 [correct]
        [Good Checksum: True]
        [Bad Checksum: False]
X Display Manager Control Protocol

No.     Time        Source                Destination           Protocol Info
      4 29.490667   192.168.1.7           192.168.1.255         XDMCP    Broadcast_query

Frame 4 (60 bytes on wire, 60 bytes captured)
Ethernet II, Src: AsustekC_be:ae:ed (00:17:31:be:ae:ed), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol, Src: 192.168.1.7 (192.168.1.7), Dst: 192.168.1.255 (192.168.1.255)
User Datagram Protocol, Src Port: 53323 (53323), Dst Port: xdmcp (177)
    Source port: 53323 (53323)
    Destination port: xdmcp (177)
    Length: 16
    Checksum: 0xaa77 [correct]
        [Good Checksum: True]
        [Bad Checksum: False]
X Display Manager Control Protocol

No.     Time        Source                Destination           Protocol Info
      5 31.490806   192.168.1.7           192.168.1.255         XDMCP    Broadcast_query

Frame 5 (60 bytes on wire, 60 bytes captured)
Ethernet II, Src: AsustekC_be:ae:ed (00:17:31:be:ae:ed), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol, Src: 192.168.1.7 (192.168.1.7), Dst: 192.168.1.255 (192.168.1.255)
User Datagram Protocol, Src Port: 53323 (53323), Dst Port: xdmcp (177)
    Source port: 53323 (53323)
    Destination port: xdmcp (177)
    Length: 16
    Checksum: 0xaa77 [correct]
        [Good Checksum: True]
        [Bad Checksum: False]
X Display Manager Control Protocol

No.     Time        Source                Destination           Protocol Info
      6 32.583571   192.168.1.7           192.168.1.6           XDMCP    Query

Frame 6 (60 bytes on wire, 60 bytes captured)
Ethernet II, Src: AsustekC_be:ae:ed (00:17:31:be:ae:ed), Dst: Vmware_9d:26:d4 (00:0c:29:9d:26:d4)
Internet Protocol, Src: 192.168.1.7 (192.168.1.7), Dst: 192.168.1.6 (192.168.1.6)
User Datagram Protocol, Src Port: 53323 (53323), Dst Port: xdmcp (177)
    Source port: 53323 (53323)
    Destination port: xdmcp (177)
    Length: 16
    Checksum: 0xab6f [correct]
        [Good Checksum: True]
        [Bad Checksum: False]
X Display Manager Control Protocol

No.     Time        Source                Destination           Protocol Info
      9 32.617367   192.168.1.6           192.168.1.7           XDMCP    Willing

Frame 9 (90 bytes on wire, 90 bytes captured)
Ethernet II, Src: Vmware_9d:26:d4 (00:0c:29:9d:26:d4), Dst: AsustekC_be:ae:ed (00:17:31:be:ae:ed)
Internet Protocol, Src: 192.168.1.6 (192.168.1.6), Dst: 192.168.1.7 (192.168.1.7)
User Datagram Protocol, Src Port: xdmcp (177), Dst Port: 53323 (53323)
    Source port: xdmcp (177)
    Destination port: 53323 (53323)
    Length: 56
    Checksum: 0x83a7 [incorrect, should be 0xb559 (maybe caused by "UDP checksum offload"?)]
        [Good Checksum: False]
        [Bad Checksum: True]
X Display Manager Control Protocol

No.     Time        Source                Destination           Protocol Info
    124 169.596461  192.168.1.7           192.168.1.6           XDMCP    Query

Frame 124 (60 bytes on wire, 60 bytes captured)
Ethernet II, Src: AsustekC_be:ae:ed (00:17:31:be:ae:ed), Dst: Vmware_9d:26:d4 (00:0c:29:9d:26:d4)
Internet Protocol, Src: 192.168.1.7 (192.168.1.7), Dst: 192.168.1.6 (192.168.1.6)
User Datagram Protocol, Src Port: 60172 (60172), Dst Port: xdmcp (177)
    Source port: 60172 (60172)
    Destination port: xdmcp (177)
    Length: 15
    Checksum: 0x90b0 [correct]
        [Good Checksum: True]
        [Bad Checksum: False]
X Display Manager Control Protocol

No.     Time        Source                Destination           Protocol Info
    127 169.630098  192.168.1.6           192.168.1.7           XDMCP    Willing

Frame 127 (90 bytes on wire, 90 bytes captured)
Ethernet II, Src: Vmware_9d:26:d4 (00:0c:29:9d:26:d4), Dst: AsustekC_be:ae:ed (00:17:31:be:ae:ed)
Internet Protocol, Src: 192.168.1.6 (192.168.1.6), Dst: 192.168.1.7 (192.168.1.7)
User Datagram Protocol, Src Port: xdmcp (177), Dst Port: 60172 (60172)
    Source port: xdmcp (177)
    Destination port: 60172 (60172)
    Length: 56
    Checksum: 0x83a7 [incorrect, should be 0x9a98 (maybe caused by "UDP checksum offload"?)]
        [Good Checksum: False]
        [Bad Checksum: True]
X Display Manager Control Protocol

No.     Time        Source                Destination           Protocol Info
    128 170.003618  192.168.1.7           192.168.1.6           XDMCP    Request

Frame 128 (139 bytes on wire, 139 bytes captured)
Ethernet II, Src: AsustekC_be:ae:ed (00:17:31:be:ae:ed), Dst: Vmware_9d:26:d4 (00:0c:29:9d:26:d4)
Internet Protocol, Src: 192.168.1.7 (192.168.1.7), Dst: 192.168.1.6 (192.168.1.6)
User Datagram Protocol, Src Port: 60172 (60172), Dst Port: xdmcp (177)
    Source port: 60172 (60172)
    Destination port: xdmcp (177)
    Length: 105
    Checksum: 0x8735 [correct]
        [Good Checksum: True]
        [Bad Checksum: False]
X Display Manager Control Protocol

No.     Time        Source                Destination           Protocol Info
    129 170.010948  192.168.1.6           192.168.1.7           XDMCP    Accept 

Frame 129 (94 bytes on wire, 94 bytes captured)
Ethernet II, Src: Vmware_9d:26:d4 (00:0c:29:9d:26:d4), Dst: AsustekC_be:ae:ed (00:17:31:be:ae:ed)
Internet Protocol, Src: 192.168.1.6 (192.168.1.6), Dst: 192.168.1.7 (192.168.1.7)
User Datagram Protocol, Src Port: xdmcp (177), Dst Port: 60172 (60172)
    Source port: xdmcp (177)
    Destination port: 60172 (60172)
    Length: 60
    Checksum: 0x83ab [incorrect, should be 0x0631 (maybe caused by "UDP checksum offload"?)]
        [Good Checksum: False]
        [Bad Checksum: True]
X Display Manager Control Protocol

No.     Time        Source                Destination           Protocol Info
    130 170.540819  192.168.1.7           192.168.1.6           XDMCP    Manage

Frame 130 (71 bytes on wire, 71 bytes captured)
Ethernet II, Src: AsustekC_be:ae:ed (00:17:31:be:ae:ed), Dst: Vmware_9d:26:d4 (00:0c:29:9d:26:d4)
Internet Protocol, Src: 192.168.1.7 (192.168.1.7), Dst: 192.168.1.6 (192.168.1.6)
User Datagram Protocol, Src Port: 60172 (60172), Dst Port: xdmcp (177)
    Source port: 60172 (60172)
    Destination port: xdmcp (177)
    Length: 37
    Checksum: 0x75e8 [correct]
        [Good Checksum: True]
        [Bad Checksum: False]
X Display Manager Control Protocol

No.     Time        Source                Destination           Protocol Info
    132 172.544165  192.168.1.7           192.168.1.6           XDMCP    Manage

Frame 132 (71 bytes on wire, 71 bytes captured)
Ethernet II, Src: AsustekC_be:ae:ed (00:17:31:be:ae:ed), Dst: Vmware_9d:26:d4 (00:0c:29:9d:26:d4)
Internet Protocol, Src: 192.168.1.7 (192.168.1.7), Dst: 192.168.1.6 (192.168.1.6)
User Datagram Protocol, Src Port: 60172 (60172), Dst Port: xdmcp (177)
    Source port: 60172 (60172)
    Destination port: xdmcp (177)
    Length: 37
    Checksum: 0x75e8 [correct]
        [Good Checksum: True]
        [Bad Checksum: False]
X Display Manager Control Protocol

No.     Time        Source                Destination           Protocol Info
    137 176.547241  192.168.1.7           192.168.1.6           XDMCP    Manage

Frame 137 (71 bytes on wire, 71 bytes captured)
Ethernet II, Src: AsustekC_be:ae:ed (00:17:31:be:ae:ed), Dst: Vmware_9d:26:d4 (00:0c:29:9d:26:d4)
Internet Protocol, Src: 192.168.1.7 (192.168.1.7), Dst: 192.168.1.6 (192.168.1.6)
User Datagram Protocol, Src Port: 60172 (60172), Dst Port: xdmcp (177)
    Source port: 60172 (60172)
    Destination port: xdmcp (177)
    Length: 37
    Checksum: 0x75e8 [correct]
        [Good Checksum: True]
        [Bad Checksum: False]
X Display Manager Control Protocol

No.     Time        Source                Destination           Protocol Info
    139 184.551232  192.168.1.7           192.168.1.6           XDMCP    Manage

Frame 139 (71 bytes on wire, 71 bytes captured)
Ethernet II, Src: AsustekC_be:ae:ed (00:17:31:be:ae:ed), Dst: Vmware_9d:26:d4 (00:0c:29:9d:26:d4)
Internet Protocol, Src: 192.168.1.7 (192.168.1.7), Dst: 192.168.1.6 (192.168.1.6)
User Datagram Protocol, Src Port: 60172 (60172), Dst Port: xdmcp (177)
    Source port: 60172 (60172)
    Destination port: xdmcp (177)
    Length: 37
    Checksum: 0x75e8 [correct]
        [Good Checksum: True]
        [Bad Checksum: False]
X Display Manager Control Protocol

No.     Time        Source                Destination           Protocol Info
    411 200.556585  192.168.1.7           192.168.1.6           XDMCP    Manage

Frame 411 (71 bytes on wire, 71 bytes captured)
Ethernet II, Src: AsustekC_be:ae:ed (00:17:31:be:ae:ed), Dst: Vmware_9d:26:d4 (00:0c:29:9d:26:d4)
Internet Protocol, Src: 192.168.1.7 (192.168.1.7), Dst: 192.168.1.6 (192.168.1.6)
User Datagram Protocol, Src Port: 60172 (60172), Dst Port: xdmcp (177)
    Source port: 60172 (60172)
    Destination port: xdmcp (177)
    Length: 37
    Checksum: 0x75e8 [correct]
        [Good Checksum: True]
        [Bad Checksum: False]
X Display Manager Control Protocol

tutto ok tranne quel cheksum errato.. ma che cmq sembra che nn serva a nulla x nn accettare la connessione...
xo' se notate nelle varie request d manage l'intervallo d tempo che le separa l'una dall'altra e' a crescita esponenziale.. (2-4-8-16) che se nn ricordo male serve per inviare delle richieste in modo tale da nn accavallare dei segnali in caso d due connessioni contemporanee.. o una roba simile.. correggetemi se sbaglio.

[sacarde]

che sistemi e che DE usi?

[andrew1988]

in entrambi ubuntu 8.10 GNOME, nel notebook sn in virtual machine su vmware e il fisso e' installato sul fisico

[sacarde]

in
/etc/gdm/custom.conf

hai:

[xdmcp]
Enable=true


p.s.
potrebbe essere un problema della virtualizzazione?
prova con un livecd

[andrew1988]

il file in questione da me e' gdm.conf-costum ed e' il seguente:

[daemon]

TimedLoginEnable=true
RemoteGreeter=/usr/lib/gdm/gdmgreeter

[security]

AllowRemoteRoot=true
AllowRoot=true
CheckDirOwner=false

[xdmcp]

Enable=true

[gui]

[greeter]

Use24Clock=true
UseInvisibleInEntry=true
IncludeAll=false
Include=remote,andrea

[chooser]

[debug]

Enable=true

[servers]

dunque nn e' quello il problema...
x la virtualizzazione nn penso manco quello.. la connessione e' bridged x cui come ip ho uno della stessa subnet.. cioe'.. nn e' che questa sia una cosa che m serva.. ma m scoccia nn riuscire in un'operazione apparentemente facile come un login remoto..

[sacarde]

io e' nelle difficolta' che imparo qualcosa

[andrew1988]

...aiuto...

[sacarde]

http://ubuntrucchi.wordpress.com/200...sistema-linux/

[andrew1988]

gia... seguito il tutorial pari pari ma il problema persevera...

[sacarde]

qualche connessione funziona?

- ssh (con forward X11)
- vnc

?

[andrew1988]

funziona??
vnc si funziona
samba si
ftp si
ssh.... nn saprei neanche come testarla

che hai in mente x farmi tale domanda???

[sacarde]

i log controllati?


p.s.
non mi ricordo se sul server , X deve stare attivo o no

[andrew1988]

nn capisco il motivo.. ma ho provato a condividere ora una cartella ul pc e cercare d accedervi dal notebook con smb... ma nn trova gli host...e cio succede in entrambe le direzioni...........................
ma si pingano!!!

[andrew1988]

sacarde!!... ho scoperto quel'e' il problema.. e' il pc!!! con un altro si connette senza problemi in xdmcp..................................................................................



detto cio moderatori chiudete pure questo topic inutile..!!

e grazie della pazienza.... :inchino: