[Samba] remote subnet browsing

[Lukasz Stelmach]

Greetings.

I try to set up cross subnet browsing but I've encountered some
difficulties. Let me introduce my situation

10.1.2.0                  10.1.1.0
A_N1 -+                   +- A_N1
      |                   |
B_N1 -+--[R1]=======[R2]--+- B_N2
.     |   VPN accross     |    .
.     |   the Internet    |    .
Z_N1 -+                   +- Z_N

A_N1 is 10.1.2.4, PDC
A_N2 is 10.1.1.1, BDC

the vpn makes everything look as if there was only one router
between two networks (except of course of ping times). Please
also note that I am aware of the difference between browsing
and name resolution.

In both networks there is the same DOMAIN. A_N[12] act as PDC and
BDC, respectively. There is however a detail that makes the situation
a little bit different than the one in the Samba3-HOWTO (ch.9).
Both A_N1 and A_N2 run wins server, that's because I don't full
trust the vpn. This forses using "remote announce" and "remote
browse sync" 

There is something wierd, however, I can't find (smbclient -L A_N2 -N)
any machines from N1 on the BDC. Instead i get messages like these on A_N2

process_host_announce: from A_N1<00> IP 10.1.2.4 to DOMAIN<1d> for server A_N1.
write_browse_list: Wrote browse list into file /var/cache/samba/browse.dat
process_master_browser_announce: Local master announce from A_N1 IP 10.1.2.4.
process_master_browser_announce: Not configured as domain master - ignoring master announce.

which seem to be triggered by these packets

11:55:36.244688 IP (tos 0x0, ttl  64, id 68, offset 0, flags [DF], proto: UDP (17), length: 242) 10.1.2.4.138 > 10.1.1.1.138: [bad udp cksum 7635!] 
>>> NBT UDP PACKET(138) Res=0x110A ID=0x7F01 IP=10 (0xa).1 (0x1).2 (0x2).4 (0x4) Port=138 (0x8a) Length=200 (0xc8) Res2=0x0
SourceName=A_N1           NameType=0x00 (Workstation)
DestName=DOMAIN         NameType=0x1D (Master Browser)

SMB PACKET: SMBtrans (REQUEST)
SMB Command   =  0x25
Error class   =  0x0
Error code    =  0 (0x0)
Flags1        =  0x0
Flags2        =  0x0
Tree ID       =  0 (0x0)
Proc ID       =  0 (0x0)
UID           =  0 (0x0)
MID           =  0 (0x0)
Word Count    =  17 (0x11)
TotParamCnt=0 (0x0) 
TotDataCnt=46 (0x2e) 
MaxParmCnt=0 (0x0) 
MaxDataCnt=0 (0x0)
MaxSCnt=0 (0x0) 
TransFlags=0x0 
Res1=0x0 
Res2=0x0 
Res3=0x0
ParamCnt=0 (0x0) 
ParamOff=0 (0x0) 
DataCnt=46 (0x2e) 
DataOff=86 (0x56) 
SUCnt=3 (0x3)
Data: (6 bytes)
[000] 01 00 01 00 02 00                                 \001\000\001\000\002\000 
smb_bcc=63
Name=\MAILSLOT\BROWSE
BROWSE PACKET
BROWSE PACKET:
Type=0x1 (HostAnnouncement)
UpdateCount=0x2056
Res1=0xBF
AnnounceInterval=2 (0x2)
Name=A_N1           NameType=0x00 (Workstation)
MajorVersion=0x4
MinorVersion=0x9
ServerType=0x9A2B
ElectionVersion=0x10F
BrowserConstant=0xAA55
Data: (14 bytes)
[000] 53 65 72 77 65 72 20 70  6C 69 6B A2 77 00        Serwer p lik\242w\000



11:55:36.246539 IP (tos 0x0, ttl  64, id 69, offset 0, flags [DF], proto: UDP (17), length: 203) 10.1.2.4.138 > 10.1.1.1.138: [bad udp cksum a4ee!] 
>>> NBT UDP PACKET(138) Res=0x100A ID=0x7F02 IP=10 (0xa).1 (0x1).2 (0x2).4 (0x4) Port=138 (0x8a) Length=161 (0xa1) Res2=0x0
SourceName=A_N1           NameType=0x00 (Workstation)
DestName=*               NameType=0x00 (Workstation)

SMB PACKET: SMBtrans (REQUEST)
SMB Command   =  0x25
Error class   =  0x0
Error code    =  0 (0x0)
Flags1        =  0x0
Flags2        =  0x0
Tree ID       =  0 (0x0)
Proc ID       =  0 (0x0)
UID           =  0 (0x0)
MID           =  0 (0x0)
Word Count    =  17 (0x11)
TotParamCnt=0 (0x0) 
TotDataCnt=7 (0x7) 
MaxParmCnt=0 (0x0) 
MaxDataCnt=0 (0x0)
MaxSCnt=0 (0x0) 
TransFlags=0x0 
Res1=0x0 
Res2=0x0 
Res3=0x0
ParamCnt=0 (0x0) 
ParamOff=0 (0x0) 
DataCnt=7 (0x7) 
DataOff=86 (0x56) 
SUCnt=3 (0x3)
Data: (6 bytes)
[000] 01 00 01 00 02 00                                 \001\000\001\000\002\000 
smb_bcc=24
Name=\MAILSLOT\BROWSE
BROWSE PACKET
BROWSE PACKET:
Type=0xD (MasterAnnouncement)
MasterName=A_N1

>From time to time I also get:

find_domain_master_name_query_fail:
Unable to find the Domain Master Browser name DOMAIN<1b> for the workgroup DOMAIN.
Unable to sync browse lists in this workgroup.

I am quite confused with all this because that is not what I'd expect
when I use remote browse sync.

Best regards.
PS. please CC answers
-- 
Miłego dnia
>Łukasz<