Novell Help Librarian Data File Version 1.00 COPYRIGHT (c) 1985 by Novell, Inc. All Rights Reserved. Save Changes? TRAP LOG HELP SNMP trap messages are used to report significant TCP/IP events. The SNMPLOG NLM processes trap messages sent to the local TCP/IP node and writes them to disk. This screen displays those traps, with the most recent traps listed first. Upon exit from this display, the trap log file can either be deleted or preserved. The following fields are displayed for each trap message: Trap Type Indicates the event type triggering each trap message. Six trap types are defined to report TCP/IP coldstart, warmstart, link down, link up, request authentication failure, and egp neighbor loss. A seventh trap type is used to report enterprise-specific (vendor-specific) events. Enterprise-specific event codes are displayed following the trap type indication. Page 1 of 2 TRAP LOG HELP Hostname field Indicates the hostname or IP address of the TCP/IP node which issued each trap message. Symbolic hostnames are in net\tcp\hosts file. IP addresses are displayed in dotted decimal notation. The tab key toggles between symbolic name and address display formats. Timestamp field Indicates the date and time each trap message was received and processed by the local TCP/IP node. Page 2 of 2 ADDRESS TRANSLATION HELP The address translation table contains the IP address to physical address equivalences. For each IP address, a physical address and an interface number is maintained. TCP/IP nodes uses the Address Resolution Protocol (ARP) to obtain address translation information. The and keys allow creation and deletion of table entries. The key allows modification of an existing table entry. Page 1 of 1 ICMP STATISTICS HELP This display presents the Internet Control Message Protocol (ICMP) input and output statistics. All objects in this group are read only. To obtain help for a given statistic object, position the highlight on the desired object field using the cursor keys, select the object, then press for help. Page 1 of 1 SELECT TARGET HOST HELP This display allows selection of the target TCP/IP host node. Once contacted, all network management objects maintained by the TCP/IP node are available for access. Either a hostname or IP address in dotted decimal notation may be used. Symbolic hostnames are in the net\tcp\hosts file. Page 1 of 1 IP ADDRESS TABLE HELP The IP Address table displays the local IP address(s) of the selected TCP/IP node. Each entry contains a hostname or IP address, an address mask in dotted decimal notation, the network interface number of the interface supporting the IP address, and an indication of the type of IP broadcast address supported by the node. The tab key toggles the hostname field between symbolic hostname and dotted decimal address representation. All table objects are read only. Page 1 of 3 IP ADDRESS TABLE HELP Hostname The hostname or IP address to which this entry's address information is associated. Symbolic hostnames are in the net\tcp\hosts file. Address Mask The subnet mask associated with the IP address of this entry. The value of the mask is an IP address with all network bits set to 1 and all host bits set to 0. Page 2 of 3 IP ADDRESS TABLE HELP Interface The index value which uniquely identifies the network interface to which this entry is applicable. Broadcast The value of the least-significant bit of the IP broadcast address used for sending datagrams on the specified interface. Page 3 of 3 IP ROUTING TABLE HELP The IP Routing table displays an entry for each route known to the selected TCP/IP host system. Each entry contains the destination network name or IP address, the next hop hostname or IP address, the network interface number associated with the next hop, the relative cost of the route, and the type of route. The tab key toggles between symbolic name and dotted decimal address representation of the destination and next hop fields. The and keys allow creation and deletion of routing entries. The key allows examination and modification of additional information associated with the highlighted route entry. Page 1 of 1 IP STATISTICS GROUP HELP This display presents the Internet Protocol (IP) input and output statistics. It also contains the IP Forwarding and IP Default Time To Live (TTL) parameters. All statistical objects are read only, while the Forwarding and Default TTL parameters are read write. To obtain help for a given statistical object, position the highlight on the desired object field using the cursor keys, select the object, then press for help. Page 1 of 1 TCP CONNECTION TABLE HELP The TCP Connection table displays an entry for each TCP connection maintained by the selected TCP/IP host system. Each entry contains the source hostname or IP address, source port, destination hostname or IP address, destination port, and the connection state. Symbolic hostnames are in the net\tcp\hosts file. The tab key toggles between hostname and dotted decimal address representation of the source and destination nodes. All TCP connection table fields are read only. TCP STATISTICS GROUP HELP This display presents the Transmission Control Protocol (TCP) input and output statistics. All statistical objects are read only. To obtain help for a given statistical object, position the highlight on the desired object field using the cursor keys, select the object, then press for help. Page 1 of 1 UDP STATISTICS GROUP HELP This display presents the User Datagram Protocol (UDP) input and output statistics. All statistical objects are read only. To obtain help for a given statistical object, position the highlight on the desired object field using the cursor keys, select the object, then press for help. Page 1 of 1 COMMUNITY NAME HELP Specifies the community name included in each SNMP request message. This name is used by the SNMP agent to determine the type of management object access which should be granted. The LAN WorkPlace SNMP agent community name defaults are "public" for read-only access and "disabled" for read/write access. Community names can be changed at SNMP agent load time. Other SNMP agent implementations may require different community names. The community name must match the name established for the SNMP agent at the selected target host. A community name mismatch causes the remote SNMP agent at the target to discard LWPCON request messages. When this occurs the summary display shows "unknown" for all statistic values and "HOST UNAVAILABLE" in the lower right corner. INTERFACE HELP The interface table displays the network interfaces supported by the selected TCP/IP host system. Each entry contains a textual description of the interface type, the interface number and the physical address. The key allows examination of statistics objects associated with the highlighted interface. Page 1 of 1 ifLastChange HELP The selected TCP/IP node's uptime when the interface last changed operational state. REQUEST RETRY HELP Specifies the number of consecutive unanswered requests to be issued prior to indicating that the selected TCP/IP node is unreachable. REQUEST POLL HELP Specifies the rate in seconds at which the specified TCP/IP node will be polled to update management statistics. The poll rate must be between 0 and 900 seconds. A value of zero causes continuous polling. REPLY TIMEOUT HELP Specifies the time period in seconds to wait for a response from the selected TCP/IP node prior to processing the SNMP request as unanswered. SNMP HELP Summary statistics for the selected TCP/IP node are displayed at the top of the screen. These values, which represent the most interesting information from a number of MIB statistic groups, are described below. LWPCON also displays an "Available Actions" menu in the center of the screen, which allows access to other features of the utility. These features are described following the summary statistics description. Page 1 of 5 TCP/IP SUMMARY HELP Uptime The amount of time that has elapsed since the selected TCP/IP host node was last initialized. ipReceives The number of input datagrams received from all interfaces, including those received in error. ipTransmits The number of datagrams given to IP for transmission. This statistical object does not include datagrams forwarded by this node. Page 2 of 5 TCP/IP SUMMARY HELP ipForwarding The number of IP packets forwarded from one node to another. This field displays "DISABLED" if the selected node is not configured to be an IP gateway. tcpReceives The number of TCP segments received, including those received in error. tcpTransmits The number of TCP segments sent, excluding those containing only retransmitted data. Page 3 of 5 TCP/IP SUMMARY HELP tcpConnects The number of currently established TCP connections. udpReceives The number of UDP datagrams delivered to UDP users. udpTransmits The number of UDP datagrams sent by UDP users on this node. Page 4 of 5 AVAILABLE ACTIONS HELP Options Allows access to parameters controlling LWPCON's behavior. Statistics Allows access to the four TCP/IP MIB statistic groups. Tables Allows access to the five TCP/IP MIB information tables. Page 5 of 5 OPTIONS HELP These configurable parameters control LWPCONs behavior. To obtain detailed help for a specific option highlight the parameter field press and then press for help. Community Name The community name included in each request message sent to the selected TCP/IP node. Request Retry The number of consecutive unanswered requests to be issued prior to indicating that the selected TCP/IP node is unreachable. Page 1 of 2 OPTIONS HELP Request Poll Interval The rate in seconds at which the specified TCP/IP node will be polled to update management statistics. Reply Timeout Interval The time period in seconds to wait for a response from the selected TCP/IP node prior to processing the request as unanswered. Page 2 of 2 ifDescr HELP A text string containing information about the interface. This string can include the name of the manufacturer, the product name, and the version of the hardware interface. ifType HELP The type of interface, distinguished according to the physical/link/network protocol(s) immediately "below" IP in the protocol stack. ifPhysAddress HELP The interface's address at the protocol layer immediately "below" IP in the protocol stack. Interfaces which do not have a physical address, such as serial line, display a value of zero. ifIndex HELP A unique value for each network interface. Its value ranges between one and the total number of interfaces maintained by the TCP/IP node. This value remains constant from one reinitialization of the TCP/IP node to the next. ifMtu HELP The size, in bytes, of the largest IP datagram which can be sent or received on the network interface. ifInOctets HELP The number of bytes received on the interface, including framing characters. ifInUcatsPkts HELP The number of (subnet) unicast packets delivered to a higher-level protocol. ifInNUcastPkts HELP The number of non-unicast (subnet broadcast or subnet multicast) packets delivered to a higher- level protocol. ifInDiscards HELP The number of inbound packets which were chosen to be discarded, even though no errors had been detected, to prevent their delivery to a higher- level protocol. ifInUnknownProtos HELP The number of packets received which were discarded because of an unknown or unsupported protocol. ifSpeed HELP An estimate of the interface's current bandwidth in bits per second. For interfaces which do not vary in bandwidth or for those where no accurate estimation can be made, ifSpeed reflects the nominal bandwidth. ifAdminStatus HELP The desired state of the interface. The "testing" state indicates that no operational packets will be passed. ifAdminStatus is a read/write object. The key allows modification of this object. Changing this object has no effect on the operation of LAN WorkPlace TCP/IP nodes. if OperStatus HELP The current operational state of the interface. The "testing" state indicates that no operational packets will be passed. ifOutOctets HELP The number of bytes transmitted out of the interface, including framing characters. ifOutUcastPkts HELP The number of packets that higher-level protocols requested be transmitted to a subnet-unicast address, including those that were discarded or not sent. ifOutNUcastPkts HELP The number of packets that higher-level protocols requested be transmitted to a non-unicast (subnet broadcast or subnet multicast) address, including those that were discarded or not sent. ifOutDiscards HELP The number of outbound packets which were chosen to be discarded even though no errors had been detected to prevent their transmission. One possible reason for discarding packets could be to free up buffers. ifOutErrors HELP The number of outbound packets that could not be transmitted because of errors. ifOutQLen HELP The length of the output packet queue (in packets). ifInErrors HELP The number of inbound packets that contained errors, and therefore could not delivered to a higher-level protocol. INTERFACE GROUP HELP This display presents the complete set of statistical objects for the selected interface. The ifAdminStatus object is read/write. All others are read only. To obtain help for a given statistical object, position the highlight on the desired object field using the cursor keys, select the object, then press for help. icmpInMsgs HELP The number of ICMP messages which the entity received. Note that this statistical object includes all messages reflected by icmpInErrors. icmpInErrors HELP The number of ICMP messages which the entity received but determined as having errors, such as bad ICMP checksum, bad length, etc. icmpInDestUnreachs HELP The number of ICMP Destination Unreachable messages received. icmpTimeExcds HELP The number of ICMP Time Exceeded Messages received. icmpInParmProbs HELP The number if ICMP Parameter Problem messages received. icmpInSrcQuenchs HELP The number of ICMP Source Quench messages received. icmpInRedirects HELP The number of ICMP Redirect messages received. icmpInEchos HELP The number of ICMP Echo Request messages received. icmpInEchoReps HELP The number of ICMP Echo Reply messages received. icmpInTimestamps HELP The number of ICMP Timestamp request messages received. icmpTimestampReps HELP The number of ICMP Timestamp reply messages received. icmpInAddrMasks HELP The number of ICMP Address Mask request messages received. icmpAddrMaskReps HELP The number of ICMP Address Mask reply messages received. icmpOutMsgs HELP The total number of ICMP messages this entity attempted to send. Note that this statistical object includes all messages reflected by icmpOutErrors. icmpOutErrors HELP The number of ICMP messages which this entity did not send due to problems discovered within ICMP, such as lack of buffers. icmpOutDestUnreachs HELP The number of ICMP Destination Unreachable messages sent. icmpOutTimeExcds HELP The number of ICMP Time Exceeded messages sent. icmpOutParmProbs HELP The number of ICMP Parameter Problem messages sent. icmpOutSrcQuenchs HELP The number of ICMP Source Quench messages sent. icmpOutRedirects HELP The number of ICMP Redirect messages sent. icmpOutEchos HELP The number of ICMP Echo request messages sent. icmpOutEchoReps HELP The number of ICMP Echo reply messages sent. icmpOutTimestamps HELP The number of ICMP Timestamp request messages sent. icmpOutTimestampReps HELP The number of ICMP Timestamp reply messages sent. icmpOutAddrMasks HELP The number of ICMP Address Mask request messages sent. icmpOutAddrMaskReps HELP The number of ICMP Address Mask reply messages sent. icmpOutAddrMaskReps HELP The number of ICMP Address Mask reply messages sent. IP ROUTING ENTRY HELP This display presents the complete set of routing parameters for the selected indirect route. The ipRouteProto parameter is read only. All others are read/write. To obtain help for a given route parameter, position the highlight on the desired field using the cursor keys, select the field, then press for help. Page 1 of 1 ipRouteDest HELP The destination IP network address of this indirect route. An entry with a value of 0.0.0.0 is considered a default route. This value is read-only for existing routing table entries; it must however be specified when creating a new entry. ipRouteNextHop HELP The IP address of the next hop on this indirect route. ipRouteIfIndex HELP The index value which uniquely identifies the local network interface through which the next hop of this route will be reached. The interface identified by a particular value of this index is the same interface as identified by the same value of ifIndex. ipRouteType HELP Defines the type of route in the following terms: direct A route to a directly connected (local) network or sub-network. invalid A route which has been previously invalidated. Specifying a route type of invalid causes that routing table entry to be deleted. other A route which does not conform to any of these definitions. remote A route to an indirectly connected (non-local) host, network, or subnetwork. ipRouteProto HELP The routing mechanism via which this route entry was established, as explained below: other none of the following types. local a route established via some manual non- protocol configuration method. Routes established via IPConfig show this type. netmgmt a route established vis a network management protocol. Routes established via TCPCon show this type. Page 1 of 2 ipRouteProto HELP icmp a route obtained via an ICMP redirect message. rip a route obtained via a Routing Information Protocol (RIP) message. egp a route obtained via an alternate routing ggp protocol. hello is-is es-is etc. Page 2 of 2 ipRouteAge HELP The elapsed time, in days:hours:minutes:seconds format, since this route was last updated or otherwise determined to be correct. The concept of a stale route is specific to the routing protocol used to maintain the route. ipRouteMetric1 HELP The primary routing metric (cost) for this route. The semantics for this metric are determined by the routing protocol specified by the ipRouteProto value. An unused metric contains a value of -1. ipRouteMetric HELP An alternate routing metric for this route. The semantics for this metric are determined by the routing protocol specified by the ipRouteProto value. All unused metric contain a value of -1. tcpRtoAlgorithm HELP The algorithm used to determine the timeout value used for retransmitting unacknowledged bytes. tcpRtoMin HELP The minimum value permitted by the selected TCP/IP node for the retransmission timeout, measured in milliseconds. More refined semantics for objects of this type depend upon the algorithm used to determine the retransmission timeout. tcpRtoMax HELP The maximum value permitted by the selected TCP/IP node for the retransmission timeout, measured in milliseconds. More refined semantics of this type depend upon the algorithm used to determine the retransmission timeout. tcpMaxConn HELP The maximum number of TCP connections that the selected TCP/IP node can support. Nodes where the maximum number of connections are dynamic set tcpMaxConn to -1. tcpActiveOpens HELP The number of times TCP connections have made a direct transition to the SYN-SENT state from the CLOSED state. tcpPassiveOpens HELP The number of times TCP connections have made a direct transition to the SYN-RCVD state from the LISTEN state. tcpAttemptFails HELP The number of times TCP connections have made a direct transition to the CLOSED state from either the SYN-SENT or the SYN-RCVD state, plus the number of times TCP connections have made a direct transition to the LISTEN state from the SYN-RCVD state. tcpEstabResets HELP The number of times TCP connections have made a direct transition to the CLOSED state from either the ESTABLISHED state or the CLOSE-WAIT state. tcpCurrEstab HELP The number of currently established TCP connections. tcpInSegs HELP The number of TCP segments received, including those received in error. tcpOutSegs HELP The number of TCP segments sent, excluding those containing only retransmitted bytes. tcpRetransSegs HELP The number of segments retransmitted; - that is, the number of TCP segments transmitted containing one or more previously transmitted bytes. udpInDatagrams HELP The number of UDP datagrams delivered to UDP users. udpNoPorts HELP The number of received UDP datagrams for which there was no receiving application at the destination port. udpInErrors HELP The number of received UDP datagrams that could not be delivered for reasons other than lack of a receiving application at the destination port. udpOutDatagrams HELP The number of UDP datagrams sent from the selected TCP/IP node. ipForwarding HELP This parameter controls whether the selected TCP/IP node functions as an IP gateway or as a host. Gateways forward IP packets from one interface to another when appropriate. Hosts simply discard any arriving packet not addressed to them. ipDefaultTTL HELP The default value inserted into the Time-To-Live field of the IP header of datagrams originating at this entity, whenever a TTL value is not supplied by the the transport layer protocol. The TTL value cannot be larger than 255. ipInReceives HELP The number of IP packets received from all network interfaces, including those received with errors. ipInHdrErrors HELP The number of input datagrams discarded due to errors in their IP headers, including bad checksums, version number mismatches, other format errors, Time-To-Live exceeded errors, errors discovered in processing their IP options, etc. ipInAddrErrors HELP The number of input datagrams discarded because the IP address in their header's destination field was not a valid address to be received at this entity. This count includes invalid addresses (0.0.0.0) and addresses of unsupported classes (Class E). For entities which are not IP Gateways and therefore do not forward datagrams, this statistical object includes datagrams discarded because the destination address was not a local address. ipForwDatagrams HELP The number of input datagrams for which this entity was not the final IP destination; as a result, attempts were made to find routes to forward them to their final destinations. In entities which do not act as IP gateways, this statistical object reflects only those packets which were source-routed via this entity, and for which the source-route processing option was successful. ipInUnknownProtos HELP The number of locally addressed datagrams received successfully but discarded because of an unknown or unsupported protocol. ipInDiscards HELP The number of input IP datagrams for which no problems were encountered to prevent their continued processing, but were discarded. One possible reason for discarding such packets could be to free up buffer space. This statistical object does not include any datagrams discarded while awaiting reassembly. ipInDelivers HELP The number of input datagrams successfully delivered to IP user protocols (including ICMP). ipOutRequests HELP The number of datagrams given to IP for transmission. This statistical object does not include any datagrams counted in ipForwDatagrams. ipOutDiscards HELP The number of output IP datagrams for which no problem was encountered to prevent their transmission to their destination, but which were discarded. One reason to discard such a packet would be lack of buffer space. This statistical object includes datagrams counted in ipForwDatagrams if any such packets met this discard criterion. ipOutNoRoutes HELP The number of IP datagrams discarded because no route could be found to transmit them to their destination. This statistical object includes any packets counted in ipForwDatagrams which meet this "no-route" criterion. ipReasmTimeout HELP The maximum number of seconds for which received fragments are held while they are awaiting reassembly at this entity. ipReasmReqds HELP The number of IP fragments received which needed to be reassembled at this entity. ipReasmOKs HELP The number of IP datagrams successfully reassembled. ipReasmFails HELP The number of failures detected by the IP reassembly algorithm for any reason, such as timeout, etc. ipFragOKs HELP The number of IP datagrams that have been successfully fragmented at this entity. ipFragFails HELP The number of IP datagrams that have been discarded because they needed to be fragmented at this entity but could not be because their "don't fragment" flag was set. ipFragCreats HELP The number of IP datagram fragments that have been generated as a result of fragmentation at this entity. TCP/IP STATISTICS HELP This menu allows access to each of the TCP/IP statistical object groups. Most statistics are read only, identified by a colon ":" following the field name. Read/write statistics are identified by a colon/period ":." combination. Note that write access to a statistical object may require a different SNMP community name. Refer to the Options menu for help on community names. All statistical object displays are dynamically updated at a configurable interval also specified in the Options menu. Page 1 of 1 TCP/IP TABLES HELP This menu allows access to each of the TCP/IP table groups. Tables can be scrolled with the up and down arrow keys. The last entry in each table identifies the table end. A null table contains only the table end entry. Table entries can be selected to allow a more detailed display of the desired entry. Read-only table fields are identified with a colon ":" following the field name. Read/write fields are identified with a colon/period ":." combination. Note that write access to table fields may require a different SNMP community name. Refer to the Options menu for help on community names. Page 1 of 1 ADDRESS TRANSLATION ENTRY HELP This display presents the complete set of address translation parameters for the selected entry. The atNetAddress, atPhysAddress, and atIfIndex entries are read/write. To obtain help for a given entry, position the highlight on the desired field using the cursor keys, select the field, then press for help. Page 1 of 1 atNetAddress HELP atNetAddress represents the network address (e.g., the IP address) corresponding to the media-dependent physical address. atNetAddress can be represented by the local hostname or IP address in dotted format. For example, andy or 130.57.7.77 atPhysAddress HELP atPhysAddress represents the media-dependent physical address. atPhysAddress can be represented in hex format. For example, for ethernet, 00-00-00-1B-1F-1C atIfIndex HELP atIfIndex represents a number which identifies a particular interface and has the same value as ifIndex. atIfIndex can be represented by an integer. MAIN MENU HELP This is the main menu of the DOS LAN WorkPlace TCP/IP console. The options available at this level are: Local Workstation Information/statistics about the local workstation. Remote Host Information/statistics about the remote host. Services Echo test (ping), Trace Route, Name Resolver, and other information from the Domain Name System such as canonical name, host information and well-known service. LOCAL/REMOTE WORKSTATION HELP Overview This menu selection provides information such as hostname, IP adddress, subnet mask, router, interface name, and interface address. Interfaces This menu selection provides more detailed statistics about the different interfaces on the system, provided their drivers are loaded and bound to the LSL. Protocols This menu selection displays some TCP, IP, UDP and ICMP summary statistics. Tables This menu selection allows access to the five TCP/IP MIB information tables. This menu selection allows access to all SNMP MIB-1 objects. OVERVIEW HELP This screen displays the primary hostname or IP address, an address mask and a router address associated with this IP address, a textual description of the interface type, and the physical address of the interface supporting the IP address. Interface Help This screen displays information about the interface that was selected. It contains information such as Name -- product or manufacturer name. Type -- distinguished according to the physical/link/network protocol(s) immediately below IP in the protocol stack. Physical Address -- the interface's address at the protocol layer immediately below IP in the protocol stack. Page 1 of 3 IP Address -- associated with the interface. Subnet Mask -- address mask associated with the interface. Size -- in bytes of the largest datagram which can be sent or received on the interface. Speed -- interfaces bandwidth in bits per second. Packets Received -- number of packets received by the interface, including error packets. Packets Sent -- number of packets transmitted by the interface. Page 2 of 3 Inbound Packets Discarded -- number of inbound packets that were discarded even though no errors were detected. Outbound Packets Discarded -- number of outbound packets that were discarded even though no errors were detected. Inbound Packets With Errors -- number of inbound packets that contained errors, and could therefore not be delivered to a higher-level protocol. Outbound Packets With Errors -- the number of outbound packets that could not be transmitted because of errors. Page 3 of 3 PROTOCOLS HELP This screen provides a snapshot of statistics from the different protocols. IP Packets Received -- the number of IP packets received from all network interfaces, including those received with errors. Packets Sent -- the number of datagrams given to IP for transmission. Packets Discarded -- the number of inbound and outbound packets which were discarded even though no errors had been detected. Packets With Errors -- the number of inbound packets that contained errors. Page 1 of 4 ICMP Packets Received -- the number of ICMP messages received. Packets Sent -- the total number of ICMP messages this entity attempted to send. Packets With Errors -- the total number ICMP messages with errors both inbound and outbound. Page 2 of 4 TCP Packets Received -- the number of TCP segments received, including those received in error. Packets Sent -- the number of TCP segments sent, excluding those containing only retransmitted bytes. Page 3 of 4 UDP Packets Received -- the number of UDP datagrams delivered to UDP users. Packets Sent -- the total number of UDP datagrams sent from this entity. Packets With Errors -- the number of UDP datagrams that could not be delivered, for reasons other than the lack of a receiving application at the destination port. Page 4 of 4 This screen provides additional information about the selected socket. It displays the socket identifier, number of bytes in the receive queue, and number of bytes in the send queue. This information is only available for the local workstation. Trace Route Help This attempts to trace the route an IP packet would follow to some internet host. Each row of the list displays the Time to Live value, name of the gateway (if available), IP address of the gateway and the round trip time. If there is no response within the timeout interval, "Not Available" is displayed. It will attempt to reach the specified host until an ICMP Echo Reply message is received or the Time to Live value hits a max.