12-20-2017
The scanner is not in the server but somewhere on your network, internal I hope, or it may be an attack as mentionned... so in internal it seems there is something looking like a such device at the IP I pointed out - Check!
Years ago I had many HP-UX crashes once a month till I decided to write at the direction saying those "non-intrusive" devices were all but that and crashing HP servers or some mainframe devices, mostly the ones trusted and having/using NFS, the reason is mainly it opens so many connections id doesnt care for itself (MS.. OS?) but on a UNIX server the timeouts are regularly over 5 minutes so a opened port cannot be used till it is cleaned and so in such cases quickly you run out and then no one can connect, not even root and you are doomed... Once I proved where it came from the HP servers were listed out the scanning process... and now they changed system, but I have no more HP either... If you have NFS mounted on that server and the scan manages to make it unreadable then your system depending what is running will try to read desperatly and it s load will go beyond control till the system crashes...
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nfs(7) Miscellaneous Information Manual nfs(7)
NAME
nfs, NFS - network file system
DESCRIPTION
The Network File System (NFS) allows a client node to perform transparent file access over the network. By using NFS, a client node oper-
ates on files residing on a variety of servers and server architectures, and across a variety of operating systems. File access calls on
the client (such as read requests) are converted to NFS protocol requests and sent to the server system over the network. The server
receives the request, performs the actual file system operation, and sends a response back to the client.
NFS operates in a stateless manner using remote procedure calls (RPC) built on top of an external data representation (XDR) protocol. The
RPC protocol enables version and authentication parameters to be exchanged for security over the network.
A server grants access to a specific file system to clients by adding an entry for that file system to the server's file.
A client gains access to that file system using the command to request a file handle for the file system (see mount(1M)). (A file handle
is the means by which NFS identifies remote files.) Once a client mounts the file system, the server issues a file handle to the client
for each file (or directory) the client accesses. If the file is removed on the server side, the file handle becomes stale (dissociated
with a known file), and the server returns an error with set to
A server can also be a client with respect to file systems it has mounted over the network; however, its clients cannot directly access
those file systems. If a client attempts to mount a file system for which the server is an NFS client, the server returns with set to The
client must mount the file system directly from the server on which the file system resides.
The user ID and group ID mappings must be the same between client and server. However, the server maps UID 0 (the superuser) to UID -2
before performing access checks for a client. This process prevents gaining superuser privileges on remote file systems.
RETURN VALUE
Generally, physical disk I/O errors detected at the server are returned to the client for action. If the server is down or inaccessible,
the client receives the message:
where is the hostname of the NFS server. The client continues resending the request until it receives an acknowledgement from the server.
Therefore, the server can crash or power down, and come back up without any special action required by the client. The client process
requesting the I/O will block, but remains sensitive to signals (unless mounted with the option) until the server recovers. However, if
mounted with the option, the client process returns an error instead of waiting indefinitely.
AUTHOR
was developed by Sun Microsystems, Inc.
SEE ALSO
exportfs(1M), share(1M), mount(1M), mount_nfs(1M), nfsd(1M), mount(2), fstab(4), dfstab(4).
nfs(7)