Client Gets Error 53 or 3779 Before NBSESSIONS is Maxed (105205)
The information in this article applies to:
This article was previously published under Q105205
PROBLEM ID: LANMAN23.1786
SYMPTOMS
LAN Manager enhanced TCP/IP clients receive Error 53 or Error 3779
(depending on which method they use to access a LAN Manager 2.2
TCP/IP server) although the server has not reached the connection
limit set in NBSESSIONS. Once this error is returned, you can log
one client on only by logging another off. Clients already logged on to
another server that attempt to NET USE to the problem server receive
an Error 53, and clients attempting a NET LOGON to the problem server
receive an Error 3779.
CAUSE
A NET USE was not returning a transport control block (TCB), causing
the server's session count to incorrectly indicate that all sessions
were utilized.
One TCB is used per connection to maintain information for the TCP
state machine. This problem was caused by a client machine being
disconnected (turned off) from the network before the client TCP could
acknowledge the server's finish signal. Normally, the server
acknowledges the client's finish, then sends its own finish which
the client acknowledges, allowing the TCP session TCBs to time out.
When the client is disconnected from the net before the final
acknowledgment, the TCBs do not time out and the server's count
becomes incorrect.
RESOLUTION
Server time-out code was inserted to reclaim TCBs waiting for the
client to acknowledge the server side of a disconnect.
STATUS
Resolved, contact Microsoft Product Services Support for further
information.
| Modification Type: | Major | Last Reviewed: | 11/5/1999 |
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| Keywords: | KB105205 |
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