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Configuring and Troubleshooting MS DFS links in an HP 
CIFS Server (Samba) Environment  

 

 

Executive summary............................................................................................................................... 2

 

What IS MS DFS? ............................................................................................................................ 2

 

Configuring MS DFS on HP CIFS Server ................................................................................................. 2

 

Test environment .............................................................................................................................. 2

 

Configuration details ........................................................................................................................ 3

 

Modifying the smb.conf file: .......................................................................................................... 3

 

Creating the MS DFS links: ............................................................................................................ 4

 

New to SAMBA 3.x:..................................................................................................................... 5

 

Testing our MS DFS environment........................................................................................................ 6

 

How it works ................................................................................................................................... 9

 

Redundant MS DFS links ................................................................................................................. 11

 

Troubleshooting MS DFS on HP CIFS Server.......................................................................................... 13

 

Problem 1: The network path was not found...................................................................................... 13

 

Problem 2: Logon failure: unknown username or password. ................................................................ 18

 

Summary .......................................................................................................................................... 19

 

For more information.......................................................................................................................... 19

 

Summary of Contents for Rp7410 - Server - 0 MB RAM

Page 1: ...environment 2 Configuration details 3 Modifying the smb conf file 3 Creating the MS DFS links 4 New to SAMBA 3 x 5 Testing our MS DFS environment 6 How it works 9 Redundant MS DFS links 11 Troubleshooting MS DFS on HP CIFS Server 13 Problem 1 The network path was not found 13 Problem 2 Logon failure unknown username or password 18 Summary 19 For more information 19 ...

Page 2: ...ble from http software hp com with a single share with files and directories LOCAL to the server as well as MS DFS links to shares on a WIN2k and WIN2k3 server All of the information contained in this paper is equally applicable to HP CIFS Server revisions based on 2 2 x OR 3 x versions of Samba unless otherwise specified This information should also be applicable to these versions of Samba runnin...

Page 3: ... in the HP UX file system directory that is hosting the MS DFS root Notice that ALL of the modifications are done on the HP CIFS Server the windows servers that contain the actual shares being linked to require no special attention Modifying the smb conf file global workgroup DON1 NetBIOS name RKM NT server string Samba Server security DOMAIN encrypt passwords Yes Server rkm nt Dfsroot linkb linka...

Page 4: ...a single share with this property called dfsroot It points to the HP UX directory dfsroot Creating the MS DFS links cd dfsroot ln s msdfs ceres shared_stuff linka ln s msdfs mccall shared_stuff linkb ll total 0 lrwxrwxrwx 1 root sys 23 Nov 2 12 35 linka msdfs ceres shared_stuff lrwxrwxrwx 1 root sys 25 Nov 2 12 35 linkb msdfs mccall shared_stuff NOTE Compare the format of the ll output to the ln s...

Page 5: ...other server For instance consider the following share definition in the smb conf file dfsproxy msdfs root yes msdfs proxy ceres alf cpqcorp net shared_stuff When a user connects to THIS share he will get an MS DFS referral to the share named shared_stuff on the server ceres alf cpqcorp net This is in contrast to having a share that points to a local directory which has MS DFS LINKS defined IN the...

Page 6: ...Server to offer a couple of MS DFS links let s see it in action For this purpose we have created a single file on each of the linked shares ceres shared_stuff filename ceres_test txt mccall shared_stuff filename mccall_test txt Figure 2 Shares and files on CERES and MCCALL ...

Page 7: ...dows XP client mccallevo to connect to these shares THROUGH the MS DFS links we have set up on the share rkm nt dfsroot Figure 3 MS DFS links linka linkb Notice from Figure 3 that these links show up as standard folders ...

Page 8: ... we can see in Figure 4 that indeed the file we put on the mccall shared_stuff directory DOES show up So the redirection through the MS DFS link was successful We clicked on a directory in our rkm nt dfsroot share and ended up on the shared_stuff share on the ceres server ...

Page 9: ...ROR to the client The error that is returned is NT_STATUS_PATH_NOT_COVERED An MS DFS aware client such as Windows XP recognizes this special error code as a signal that the resource is a MS DFS link This triggers the client to send an NT_TRANSACT2 request for a MS DFS referral HP CIFS Server responds to this NT_TRANSACT2 request with a MS DFS referral which contains the server and share name the c...

Page 10: ...Figure 6 Highlighted line shows client request for info on linka the MS DFS link Note the response immediately after with the Error STATUS_PATH_NOT_COVERED ...

Page 11: ...ncing two or more server share referrals with the same link If the FIRST link is unavailable the client will then attempt to connect to the SECOND link and so forth Of course for this to be effective you must have some method of keeping the shares in sync in terms of the data stored on each The syntax for this is as follows ln s msdfs server1 share1 server2 share2 linkname For example if we set up...

Page 12: ...sting the MS DFS root do some form of caching in regards to links that have been followed Because of this if you change a share such that it no longer hosts MS DFS links or visa versa you may have to reboot your clients that have accessed this share It is also recommended that you restart samba after changing a share to from a MS DFS root Terpstra and Kalele in Chapter 16 of The Official Samba 3 H...

Page 13: ...nd my users can connect to the SHARE but when they click on the MS DFS link they get the following error Figure 9 Client Error returned when referral fails One way to troubleshoot this would be with a network trace using Ethereal an Open source software network sniffer You can download this excellent utility from http www ethereal com The following screenshot shows a partial trace of the network a...

Page 14: ... find the server we referred it to but is unsuccessful From the trace it clearly cannot find the server named ceres Why First let s check to make sure that the server and share we are setting the link up to is correct On the HP CIFS Server rkm nt we will do this using the smbclient utility opt samba bin smbclient ceres shared_stuff U FreddieTheFish added interface ip 16 113 9 137 bcast 16 113 63 2...

Page 15: ...ng the NetBIOS server name not found but the server proven available from at least one other source are typically indicative of a name resolution issue Let s take a look at the server again and see if we can figure out where this server is We ll use the HP UX utility nslookup nslookup ceres Name Server fwd2 cca mycompany net Address 55 155 155 55 Trying DNS Non authoritative answer Name ceres alf ...

Page 16: ...ile on the client Choice 3 is the simplest from a testing standpoint So we add the following line to the windows system32 drivers etc lmhosts file on the client 16 113 9 139 ceres PRE and reload the remote cache name table on the client from the command prompt c nbtstat R ...

Page 17: ...lient needing to follow this link But this simple method is very useful for troubleshooting NOTE Since it is the client s responsibility to directly connect to the node server and share name that the MS DFS referral response returns it is entirely possible to create MS DFS links on your HP CIFS Server share that the server itself is unable to resolve or connect to so long as the CLIENT can resolve...

Page 18: ...ntee that that same user will have access to the server that the MS DFS link will refer him to And in fact the following screen shot of a partial Ethereal trace of the network traffic involved clearly shows the authentication failure not at the HP CIFS Server rkm nt but when trying to set up a session to the referred server mccall Figure 14 Trace showing the result of a MS DFS referral to a link w...

Page 19: ...e able both to resolve the server name provided in the MS DFS referral and possess the appropriate credentials username password to connect to the share on the referred server If your clients have difficulties following a MS DFS link you have set up oftentimes a network trace of the attempt will be helpful in determining the reason for the failure MS DFS also provides some possibility of redundanc...

Page 20: ...ticles available from Microsoft on MS DFS While these are not specifically applicable to MS DFS on Samba they do give useful background and implementation information Some useful articles in this category Distributed File System DFS Best Practices and Troubleshooting Guide 812487 Overview of DFS in Windows 2000 Distributed File System Frequently Asked Questions Distributed File System White paper ...

Page 21: ...in the express warranty statements accompanying such products and services Nothing herein should be construed as constituting an additional warranty HP shall not be liable for technical or editorial errors or omissions contained herein Itanium is a trademark or registered trademark of Intel Corporation in the U S and other countries and is used under license XXXX XXXXEN 3 2005 ...

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