HP 3000 Manuals HP 3000 Manuals
ICMP Type/Code Words
The following describes how to interpret the Parameter value (Parm Value)
of a logging location that uses this value as the ICMP Type/Code Word.
The Network Transport Entities PXP SIP and TCP SIP log the event that an
ICMP message was received. The Parameter value, which is shown in
hexadecimal, must be interpreted as a two byte value. The first byte
indicates the ICMP message type and the second byte indicates the code.
The second byte is only meaningful for two types of ICMP messages,
Destination Unreachable and Time Exceeded.
The Parameter Value is in the left-hand column.
300 Cause: Destination Unreachable. A gateway or
intermediate router node was unable to forward the IP
datagram that originated from the node that logs this
message. According to the gateway or router node
routing tables, the destination network is
unreachable.
Action: Verify that the routing information about the
destination node in the configuration file of the
source (local) node is correct. Verify that the
destination node is operational. If the destination
node is in a router network, verify that the routing
information to the nodes along the datagram's path is
correct and the links and NIs are started in those
nodes. If the destination node is located in a
network different than the source (local) node, verify
that the routing information at the gateways along the
datagram's path is correct and the links and NIs are
started.
301 Cause: Destination Unreachable. A gateway or
intermediate router node was unable to forward the IP
datagram that originated from the node that logs this
message. According to the gateway or router node
routing tables, the destination node is unreachable.
Action: Verify that the routing information about the
destination node in the configuration file of the
source (local) node is correct. Verify that the
destination node is operational. If the destination
node is in a router network, verify that the routing
information at the intermediate nodes along the
datagram's path is correct and the links and NIs are
started at those nodes. If the destination node is
located in a network different than the source (local)
node, verify that the routing information at the
gateways along the datagram's path is correct and the
links and NIs are started.
302 Cause: Destination Unreachable. The destination node
was unable to deliver the IP datagram that originated
from the node that logs this message. According to
the destination node, the IP module cannot deliver the
datagram because the indicated protocol (TCP or PXP)
is not active.
Action: This ICMP message should not occur in normal
network operation between HP nodes. Contact your
Hewlett-Packard representative for assistance.
303 Cause: Destination Unreachable. The destination node
was unable to deliver the IP datagram that originated
from the node that logs this message. According to
the destination node, the IP module cannot deliver the
datagram because the socket (port) is not open.
Action: This ICMP message should not occur in normal
network operation between HP nodes. Contact your
Hewlett-Packard representative for assistance.
304 Cause: Destination Unreachable. A gateway was unable
to forward the IP datagram that originated from the
node that logs this message. The datagram must be
fragmented but the Don't Fragment Flag is on.
Action: This ICMP message should not occur in normal
network operation between HP nodes. Contact your
Hewlett-Packard representative for assistance.
305 Cause: Destination Unreachable. The gateway was
unable to deliver the IP datagram that originated from
the node that logs this message. According to the
gateway, the IP module cannot deliver the datagram
because of a source route failure. Source routes are
configured in the Options field of the IP header.
Action: This ICMP message should not occur in normal
network operation between HP nodes.
C00 Cause: Parameter Problem. The destination node or
gateway was unable to deliver the IP datagram that
originated from the node that logs this message
because of problems with the header parameters. One
potential source of such a problem is incorrect
arguments in the Options field of the IP header.
Action: This ICMP message should not occur in normal
network operation between HP nodes. Contact your
Hewlett-Packard representative for assistance.
400 Cause: Source Quench. Several things can trigger
source quench messages: (1) A gateway, intermediate
router node or destination node was unable to forward
or deliver the IP datagram because of lack of
resources (Eg. buffers). (2) A gateway, intermediate
router node or destination node was unable to forward
or deliver the IP datagram because the capacity limit
of resource (Eg. buffers) is being approached. In
this case, the IP datagram is NOT discarded. On
receipt of a source quench ICMP message, the source
will cut back its rate of TCP traffic to the
destination node specified in the ICMP message.
Source quench messages are sent to the source of the
traffic and therefore logged at the source. The
source node will gradually increase the rate at which
it sends traffic to the destination.
Action: Reception of this ICMP message can occur in
normal network operation, but if this problem
persists, it may be necessary to review the resource
allocation at the node generating the ICMP message.
It may require increasing the number of store and
forward buffers configured in the IP Protocol screen
or the number of inbound buffers configured in the
appropriate network interface screen. Care should be
taken in increasing these values since this increases
the queuing at these nodes and may result in longer
delays. It is recommended that you review the traffic
patterns and perhaps alter the routing information so
that a better path is chosen.
500 Cause: Redirect. A gateway has received an IP
datagram that originated from the node (local node)
that logs this message. It indicates that the local
node's routing information is incorrect or
out-of-date. The Redirect message will cause the
local node to send its traffic for the destination
network to the gateway specified in the Redirect
message.
Action: Reception of this ICMP message can occur in
normal network operation. Depending on the cause of
the Redirect message different actions should be
taken. If the networks are operating on the gateway
that sent the Redirect then the local node's routing
information conflicts with the gateway's routing
information. The conflict occurs when the local node
thinks that the gateway sending the Redirect (G1) is
the best path to a given network (N1), whereas G1
thinks that another gateway (G2) is best. The
Redirect will dynamically alter the routing
information in the local node so that traffic for N1
will be sent to G2 instead of G1. This new routing
information will be lost when the local node's network
transport is shut. In this case reconfigure either
the local node or gateway so the routing information
to N1 is consistent. The Redirect may also be caused
by a link failure or a network that is not operational
on the gateway (G1) that sent the Redirect. In this
case, it is possible that G1 may, depending on the
topology, misroute packets through the network.
Immediate action should be taken to correct the
failure at the gateway or reconfigure the local node
to route traffic for a given network through another
gateway.
600 Cause: Time Exceeded. A gateway or intermediate
router node found that the Time-To-Live (TTL) field in
the datagram is zero. Either a link has failed, to
cause a packet to become lost in the network or the
Time-To-Live is too short.
Action: If after verifying all links are operational,
it may be necessary to increase the Reachable Hop
Count in the Static Neighbor Gateway Reachable Network
screen during configuration. If the destination node
is on a router network it may be necessary to increase
the Network Hop Count in its Router Network Interface
screen.
601 Cause: Time Exceeded. The destination node cannot
complete the reassembly of an IP datagram within its
time limit due to missing fragments. The timer is set
at 15 seconds. Missing fragments can be caused by
fragments that are lost in the network, fragments that
are delayed for a long time (perhaps by a congested
gateway), or caused by a corrupt datagram.
Action: Reception of this ICMP message can occur
occasionally in normal network operation, but if this
problem is persistent, determine the cause of the
reassembly failure at the destination node by
verifying the routing of packets from the source
(local) node. Intermediate nodes or gateways may be
heavily congested or routing may be incorrect. If the
problem still cannot be determined, then contact HP
for assistance.