We have started having problems with a remote system connecting to an ftp server. The client system is Windows 2003. The server is Solaris running ProFTPD.
What should I look for to determine what caused the RST. Also, why is it sending out the NBSTAT queries. This system seems to be seeing a large number of checksums, but I'm not sure that this isn't a configuration issue.
15 1.930266 server client FTP Response: 230 User ftplslg logged in
16 2.103640 client server TCP 1300 > ftp [ACK] Seq=29 Ack=113 Win=65423 [TCP CHECKSUM INCORRECT] Len=0
17 2.928823 client server FTP Request: CWD inbound
18 3.016973 server client FTP Response: 250 CWD command successful
19 3.021788 client server FTP Request: PWD
20 3.114201 server client FTP Response: 257 "/inbound" is the current directory
21 3.410262 client server TCP 1300 > ftp [ACK] Seq=47 Ack=182 Win=65354 [TCP CHECKSUM INCORRECT] Len=0
22 3.883197 client server FTP Request: TYPE I
23 4.000257 server client FTP Response: 200 Type set to I
24 4.007553 client server FTP Request: PASV
25 4.095494 server client FTP Response: 227 Entering Passive Mode (192,250,23,244,201,231)
27 4.214908 client server TCP 1300 > ftp [ACK] Seq=61 Ack=253 Win=65283 [TCP CHECKSUM INCORRECT] Len=0
44 15.302055 client server NBNS Name query NBSTAT *<00><00><00><00><00><00><00><00><00><00><00><00><00><00><00>
45 16.801399 client server NBNS Name query NBSTAT *<00><00><00><00><00><00><00><00><00><00><00><00><00><00><00>
46 18.301354 client server NBNS Name query NBSTAT *<00><00><00><00><00><00><00><00><00><00><00><00><00><00><00>
47 19.804387 client server TCP 1301 > 51687 [SYN] Seq=0 Len=0 MSS=1460
48 19.890076 server client TCP 51687 > 1301 [RST, ACK] Seq=0 Ack=1 Win=0 Len=0
53 20.303322 client server TCP 1301 > 51687 [SYN] Seq=0 Len=0 MSS=1460
57 26.338282 client server TCP 1301 > 51687 [SYN] Seq=0 Len=0 MSS=1460
73 40.535942 client server FTP Request: QUIT
74 40.636636 server client FTP Response: 221 Goodbye.
75 40.637330 server client TCP ftp > 1300 [FIN, ACK] Seq=267 Ack=67 Win=49400 Len=0
76 40.637446 client server TCP 1300 > ftp [ACK] Seq=67 Ack=268 Win=65269 [TCP CHECKSUM INCORRECT] Len=0
77 40.639656 client server TCP 1300 > ftp [FIN, ACK] Seq=67 Ack=268 Win=65269 [TCP CHECKSUM INCORRECT] Len=0
