ICMP Type/Code Words

CAUSE: 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.

CAUSE: 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.

CAUSE: 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.

CAUSE: 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.

CAUSE: 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.

CAUSE: 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.

CAUSE: 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.

CAUSE: 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 (e.g., 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 (e.g., 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

CAUSE: 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.

CAUSE: 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.

CAUSE: 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.