For reasons which I shall not bother you with, decided to try changing to
using TCP when NFS mounting a file system on an Alpha running DU 4.0b. The
file system is exported from a SUN running Solaris 2.5. Days later the SUN
got very upset, the problem appeared to be a large number of packets from the
Alpha (rate approx. 1.7k per second). I captured some packets and then
reverted to the default mounting - which gives NFS V3 over UPD.
A sample packet is shown below, as captured by snoop on the SUN. It will
have been captured long after the problem started.
The packets are very short TCP. They are all NFS (from the port numbers),
all have very large TCP sequence numbers with Ack number set to zero. The
server was not seen to reply.
So, has anyone seen this before? Any idea who's problem it may be SUN
or Digital ?
Thanks
Alan Lotts
-----------------------------------------------------------------------------
ETHER: ----- Ether Header -----
ETHER:
ETHER: Packet 1 arrived at 20:09:55.47
ETHER: Packet size = 62 bytes
ETHER: Destination = 8:0:20:22:e0:9, Sun
ETHER: Source = 0:0:f8:22:e5:f4,
ETHER: Ethertype = 0800 (IP)
ETHER:
IP: ----- IP Header -----
IP:
IP: Version = 4
IP: Header length = 20 bytes
IP: Type of service = 0x00
IP: xxx. .... = 0 (precedence)
IP: ...0 .... = normal delay
IP: .... 0... = normal throughput
IP: .... .0.. = normal reliability
IP: Total length = 48 bytes
IP: Identification = 28819
IP: Flags = 0x4
IP: .1.. .... = do not fragment
IP: ..0. .... = last fragment
IP: Fragment offset = 0 bytes
IP: Time to live = 60 seconds/hops
IP: Protocol = 6 (TCP)
IP: Header checksum = b7c0
IP: Source address = ( the alpha )
IP: Destination address = (the Sun)
IP: No options
IP:
TCP: ----- TCP Header -----
TCP:
TCP: Source port = 1019
TCP: Destination port = 2049
TCP: Sequence number = 4135514624
TCP: Acknowledgement number = 0
TCP: Data offset = 28 bytes
TCP: Flags = 0x02
TCP: ..0. .... = No urgent pointer
TCP: ...0 .... = No acknowledgement
TCP: .... 0... = No push
TCP: .... .0.. = No reset
TCP: .... ..1. = Syn
TCP: .... ...0 = No Fin
TCP: Window = 32768
TCP: Checksum = 0xf92e
TCP: Urgent pointer = 0
TCP: Options: (8 bytes)
TCP: - Maximum segment size = 1460 bytes
TCP: - No operation
TCP: - Option 3 (unknown - 1 bytes) 00
TCP:
Received on Sun Apr 06 1997 - 20:31:19 NZST