TCP/IP Management Programming Manual

Commands and Responses
HP NonStop TCP/IP Management Programming Manual—529636-001
6-93
STATISTICS Command
A gateway sends this message to the TCP/IP subsystem to
indicate that the gateway is receiving datagrams more quickly than
it can process them. When the TCP/IP subsystem receives this
message, it reduces the rate at which it is sending the datagrams
by implementing a slow start. To implement a slow start, the
TCP/IP subsystem first stops sending any datagrams at all and
then gradually increases the number of datagrams sent. Note that
if the TCP/IP subsystem is doing a lot of retransmissions, you
should check to see if Source Quench packets are being received.
If they are, you should reduce the number of packets being
transmitted by your applications.
Type 5 is the Redirect message.
A gateway sends this message to the TCP/IP subsystem
(functioning as a source host) to indicate that there is a shorter
path to the destination through another gateway. When the TCP/IP
subsystem receives a Redirect message, it corrects its routing
table to reflect the new route. If a host receives many Redirect
messages in a short period of time, it is usually an indication that
the host is not correcting its routing table.
Type 8 is the Echo message.
This ICMP message is sent from the source address to the
destination address. An Echo Reply message containing the same
data is expected from the destination address.
Type 11 is the Time Exceeded message.
A gateway sends this message to notify the TCP/IP subsystem
(functioning as a source host) that the time-to-live field is zero and
that the gateway discarded the datagram. A destination host
sends this message if the host cannot reassemble a fragmented
datagram within the time limit because fragments are missing. The
destination host discards the datagram. When a Time Exceeded
message is received, you should check for routing loops.
Type 12 is the Parameter Problem message.
A host or gateway sends this message to notify the TCP/IP
subsystem (functioning as a source host) that one of its datagrams
has been discarded because the header parameters are incorrect.
Type 13 is the Timestamp message.
A host or gateway sends this message to indicate the time it last
handled the message before sending it.
Type 14 is the Timestamp Reply message.
A host or a gateway sends this message in reply to a Timestamp
message.