RFC - 869
Robert M. Hinden
BBN Communications Corporation
December 1983
3 Relationship to Other Protocols
5 Header Formats
5.1 IP Headers
5.2 HMP Header
6 HMP Monitoring Center Message Formats
6.1 Message Type 100: Polling Message
6.2 Message Type 101: Error in Poll
6.3 Message Type 102: Control acknowledgment
A Appendix A - IMP Monitoring
A.1 Message Type 1: IMP Trap
A.2 Message Type 2: IMP status
A.3 Message Type 3: IMP Modem Throughput
A.4 Message Type 4: IMP Host Throughput
B Appendix B - TAC Monitoring
B.1 Message Type 1: TAC Trap Message
B.2 Message Type 2: TAC Status
B.3 Message Type 3: TAC Throughput
C Appendix C - Gateway Monitoring
C.1 Gateway Parameters
C.2 Message Type 1: Gateway Trap
C.3 Message Type 2: Gateway Status
C.4 Message Type 3: Gateway Throughput
C.5 Message Type 4: Gateway Host Traffic Matrix
C.6 Message Type 6: Gateway Routing
-i-
A Host Monitoring Protocol
The Host Monitoring Protocol (HMP) is used to collect
This document is organized into three parts. Section 2 and
-1-
-2-
The Host Monitoring Protocol is a transaction-oriented
- The monitored entity sometimes needs to send unsolicited
datagrams to the monitoring host. The monitoring host
should be able to tell when messages from the monitored
entity have been lost in transit, and it should be able to
determine the order in which the messages were sent, but the
application does not require that all messages be received
or that they be received strictly in the same sequence in
which they were sent.
- The monitoring host needs to gather data from the monitored
entity by using a query-response protocol at the application
level. It is important to be able to determine which query
is being answered by a particular response, and to determine
whether successive responses are duplicates of previous
ones.
- The monitoring host must be able to initiate certain control
functions in the monitored entity, possibly including the
setting of parameters in the monitored entity. The
monitoring host needs to know if the control function has
been carried out.
In addition, we assume that a given monitoring host may be
-3-
Messages from the monitoring host to the monitored entity
- The monitored entity must be able to determine that this
message is in fact a poll from a monitoring host. The
"system type," "message type," and "password" fields in the
HMP header have been defined to meet this need.
- The monitored entity may need to be able to identify the
particular process on the monitoring host that sent this
poll, so it can send its response back to the right process.
The "port number" field in the HMP header has been defined
to meet this need.
- The monitored entity must be able to indicate to the
monitoring host, in its response, precisely which query is
being answered by a particular response. The "sequence
number field" has been defined to meet this need.
- The monitored entity must be able to determine just what
kind of action the monitoring host is requesting. That is,
the HMP transport protocol must provide some way of
multiplexing and demultiplexing the various higher-level
applications which use it. The "R-message type" and "R-
subtype" fields of the polling message have been defined to
meet this need.
Messages from the monitored entity to the monitoring host
- The monitoring host must be able to route this message to
the correct process. The "port number" field meets this
need.
-4-
- The monitoring host must be able to match up received
messages with the polls, if any, that elicited them. The
"returned sequence number" field in the HMP header has been
defined to meet this need.
- The monitoring host must be able to determine which higher
level application should receive a particular message. The
"system type" and "message type" fields are used for this
purpose.
- The monitoring host must be able to determine whether some
messages of a given type were lost in transit, and whether
messages have arrived out of sequence. Although this
function, strictly speaking, belongs to the application and
not to the transport layer, the HMP header contains a
"sequence number" for this purpose.
In addition, a simple one's complement checksum is provided
-5-
The Host Monitoring Protocol is a transport protocol
+------+ +------+ +-------+ +------+
|TELNET| ...| FTP | |GATEWAY| ... | TAC | Application Layer
+------+ +------+ +-------+ +------+
| | | |
| | | |
|__________| |_____________|
| |
+------+ +-------+
| TCP | | HMP | Transport Layer
+------+ +-------+
| |
| |
+-------------------------------------+
| Internet Protocol & ICMP | Internetwork Layer
+-------------------------------------+
|
+------------------------+
| Local Network Protocol | Network Layer
+------------------------+
-6-
The HMP is built around the idea that most of the
Consequently, the HMP is based on polling hosts for
-7-
Traps report spontaneous events, as they occur, to the
Status information, the second type of data collected by the
-8-
The third type of data collected by the HMP is statistical
The collection frequency for statistics messages from a
-9-
The HMP also includes a provision to send data to and read
To send data to a host, the monitoring center sends the host
To read parameters in a host, the monitoring center will
-10-
-11-
Host Monitor Protocol messages have the following format:
+----------------+
| Local Network |
| Header(s) |
+----------------+
| IP header |
+----------------+
| HMP |
| Header |
| |
+----------------+
| D |
| A |
| T |
| A |
+----------------+
| Padding |
+----------------+
-12-
0 0 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+---------------+---------------+
0 | System Type | Message Type |
+---------------+---------------+
1 | Port Number | Control Flag |
+---------------+---------------+
2 | Sequence Number |
+---------------+---------------+
3 | Password or Returned Seq. # |
+---------------+---------------+
4 | One's Complement Checksum |
+---------------+---------------+
The combination of system type and message type determines the format of the data in the monitoring message.
The system types which have been defined are:
System Type | Meaning
----------------+-----------------
1 | Monitoring Host
2 | IMP
3 | TAC
4 | Gateway
5 | SIMP
6 | BBN VAX/C70 TCP
7 | PAD
8 | Reserved
9 | TIU
10 | FEP
11 | Cronus Host
12 | Cronus MCS
-13-
Type | Description
----------+--------------------------
|
1 | Trap
2 | Status
3 | Thruput
4 | HTM - Host Traffic Matrix
5 | Parameters
6 | Routing
7 | Call Accounting
|
100 | Poll
101 | Error
102 | Control Acknowledgment
This field can be used to multiplex similar messages to/from different processes in one host. It is currently unused.
This field is used to pass control information. Currently Bit 15 is defined as the "More bit" which is used in a message in responce to a poll to indicate that there is more data to poll for.
Every message contains a sequence number. The sequence number is incremented when each new message of that type is sent.
The Password field of a polling message from an monitoring center contains a password to verify that the monitoring center is allowed to gather information. Responses to
polling messages copy the Sequence Number from the
polling message and return it in this field for
-14-
The Checksum field is the one's complement of the one's complement sum of all the 16-bit words in the header and data area.
-15-
The monitoring center will send polls to the hosts it is monitoring to collect their monitoring data. When the host
receives a poll it will return a message of the type
requested. It will only answer a poll with the correct
system type and password and will return an error message
(Message Type 101) if it receives a poll for the wrong
system type or an unsupported message type.
The Poll message includes a facility to send data to a monitored host. The poll message to send data consists of a
poll for a Control Acknowledgment message (type 102)
followed by the data. The R-Subtype specifies the type of
the data that is being sent. When the monitored host
receives a Poll for a Control acknowledgment, it processes
the data, and then responds with an Control acknowledgment
message. If the monitored host can not process the data, it
should respond with an error message.
A poll to read parameters consists a poll for a Parameters message. The R-Subtype specifies the type of parameters being read. When the monitored host receives a poll for a Parameters message, it responds with a Parameters message containing the requested information.
A polling message has the following form:
0 0 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+---------------+---------------+
0 | R-Message Type| R-Subtype |
+---------------+---------------+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1 | Data |
+ +
2 | |
+ +
. .
. .
n | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-16-
The type of machine being polled.
Polling Message = 100
Unused
Unused
The sequence number identifies the polling request. The Monitoring Center will maintain separate sequence numbers for each host it monitors. This sequence number is returned in the response to a poll and the monitoring center will use this information to associate polls with their responses and to determine round trip times.
The monitoring password.
The message type requested.
This field is used when sending data and reading parameters and it specifies the type of the data being sent or parameters being read.
When the poll is requesting a Control Acknowledgment
message, data is included in the poll message. A poll for
any other type of message does not include any data . The
contents of the data is host specific.
-17-
This message is sent in response to a faulty poll and specifies the nature of the error.
An error message has the following form:
0 0 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+---------------+---------------+
0 | Error Type |
+---------------+---------------+
1 | R-Message Type| R-Subtype |
+---------------+---------------+
The type of machine sending message.
Error Message = 101
Unused
Unused
A 16 bit number incremented each time an error message is sent.
The Sequence Number of the polling message which caused the error.
-18-
This field specifies the nature of the error in the poll. The following error types have been defined.
1 = Reason unspecified.
2 = Bad R-Message Type.
3 = Bad R-Subtype.
4 = Unknown parameter
5 = Invalid parameter value
6 = Invalid parameter/value format
7 = Machine in Loader
These fields identify the poll request in error.
-19-
This message is sent in response to a poll for this type of message. It is used to acknowledge poll messages that are used to set parameters in the monitored host.
The Control acknowledgment has no fields other than the HMP header.
The type of the system sending the message.
Control acknowledgment = 102
Unused
Unused
A 16 bit number incremented each time a Control
acknowledgment message is sent.
The Sequence Number of the polling message which requested this message.
-20-
When a trap occurs, it is buffered in the IMP and sent as soon as possible. Trap messages are unsolicited. If traps happen in close sequence, several traps may be sent in one message.
Through the use of sequence numbers, it will be possible to
determine how many traps are being lost. If it is
discovered that many are lost, a polling scheme might be
implemented for traps.
A IMP trap message has the following form:
0 0 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+---------------+---------------+
0 | # of traps lost |
+---------------+---------------+
1 : first :
. : trap :
. : data :
. +---------------+---------------+
. : additional :
. : trap :
. : data :
+---------------+---------------+
IMP = 2
IMP Trap Message = 1
Unused
-21-
Unused
Unused
A 16 bit number incremented each time a trap message is sent so that the HM can order the received trap messages and detect missed messages.
Under certain conditions, an IMP may overflow its internal trap buffers and be unable to save traps to send. This counter keeps track of such occurrences.
There can be several blocks of trap data in each message. The format for each such block is below.
+---------------+---------------+
| Size |
+---------------+---------------+
| Time |
+---------------+---------------+
| Trap ID |
+---------------+---------------+
: Trap :
: Data :
+---------------+---------------+
Size
Size is the number of 16 bit words in the trap, not counting the size field.
Time
The time (in 640 ms. units) at which the trap occurred.
-22-
Trap ID
This is usually the program counter at the trap. The ID identifies the trap, and does not have to be a program counter, provided it uniquely identifies the trap.
Trap Data
The IMP returns data giving more information about the trap. There are usually two entries: the values in the accumulator and the index register at the occurrence of the trap.
-23-
The status message gives a quick summary of the state of the IMP. Status of the most important features of the IMP are reported as well as the current configuration of the machine.
The format of the status message is as follows:
0 0 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+---------------+---------------+
0 | Software Version Number |
+---------------+---------------+
| Last Trap Message |
+---------------+---------------+
| Max # Hosts | Max # Modems |
+---------------+---------------+
| Max # Channels| Max # IMPs |
+---------------+---------------+
| Package bits 0-15. |
+---------------+---------------+
5 | Package bits 16.-31. |
+---------------+---------------+
| |
+ Crash +
| |
+ Data +
| |
+---------------+---------------+
| Anomalies |
+---------------+---------------+
10 | Free Pool | S+F Pool |
+---------------+---------------+
|Reassembly Pool| Allocated Pool|
+---------------+---------------+
| HIHD0 | HIHD1 | HIHD2 | HIHD3 |
. +---------------+---------------+
. : HIHD4 | ............... :
. +---------------+---------------+
(cont.)
-24-
. +---------------+---------------+
. | Modem |
. + State +
. | Data |
. +---------------+---------------+
. : Modem State :
. : Data...... :
+---------------+---------------+
IMP = 2
IMP status message = 2
Unused
Unused
A 16 bit number incremented each time a status message is sent.
The password contains the sequence number of the polling message to which this message responds.
The IMP version number.
-25-
Contains the sequence number of the last trap message sent to the HM. This will allow the HM to detect how many trap messages are being lost.
The number of configured hosts in this system.
The number of configured modems in this system.
The maximum possible number of IMP-IMP channels in this system.
The maximum possible number of IMPs in this system.
This is a bit encoded word that reports the set of packages currently loaded in the system. The table below defines the bits.
-26-
Bit Package
(octal)
(1st Word)
1 VDH
2 Logical address tables
4 Mezmode
10 Cumulative Statistics
20 Trace
40 TTY
100 DDT
200 HDLC
400 HDH
1000 Cassette Writer
2000 Propagation Delay Measurement
4000 X25
10000 Profile Measurements
20000 Self Authenticating Password
40000 Host traffic Matrix
100000 Experimental/Special
(2nd Word)
1 End-to-end Statistics
2 Store and Forward statistics
Crash data reports the circumstances surrounding an
unexpected crash. The first word reports the location of
the crash and the following two are the contents of the
accumulator and index registers.
Anomalies is a collection of bit flags that indicate the state of various switches or processes in the IMP. These
are very machine dependent and only a representative
sampling of bits is listed below.
Bit Meaning
(octal)
20 Override ON
200 Trace ON
1000 Statistics ON
2000 Message Generator ON
4000 Packet Trace ON
10000 Host Data Checksum is BAD
20000 Reload Location SET
-27-
These are four bytes of counters indicating the current usage of buffers in the IMP. The four counters are: free buffers, store-and-forward buffers, reassembly buffers and allocated buffers.
Each four bit HIHD field gives the state of the
corresponding host.
Value Meaning
0 UP
1 ready line down
2 tardy
3 non-existent
Modem state data contains six fields of data distributed over four words. The first field (4 bits) indicates the line speed; the second field (4 bits) is the number of the modem that is used by the neighboring IMP on this line; the third field (8 bits) is the number of line protocol ticks covered by this report; the fourth (1 bit) indicates line down(1) or up(0); the fifth (7 bits) is the IMP number of neighbor IMP on the line; and the sixth (8 bits) is a count of missed protocol packets over the interval specified in the third field.
-28-
The modem throughput message reports traffic statistics for each modem in the system. The IMP will collect these data at regular intervals and save them awaiting a poll from the HM. If a period is missed by the HM, the new results simply overwrite the old. Two time stamps bracket the collection interval (data-time and prev-time) and are an indicator of missed reports. In addition, mess-time indicates the time at which the message was sent.
The modem throughput message will accommodate up to fourteen modems in one packet. A provision is made to split this into multiple packets by including a modem number for the first entry in the packet. This field is not immediately useful, but if machine sizes grow beyond fourteen modems or if modem statistics become more detailed and use more than three words per modem, this can be used to keep the message within a single ARPANET packet.
The format of the modem throughput message is as follows:
0 0 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+---------------+---------------+
0 | Mess-Time |
+---------------+---------------+
| Software Version Number |
+---------------+---------------+
| Data-Time |
+---------------+---------------+
| Prev-Time |
+---------------+---------------+
| Total Modems | This Modem |
+---------------+---------------+
5 | |
. + modem +
. | |
. + throughput +
. | |
. +---------------+---------------+
. : modem :
. : :
. : throughput :
+---------------+---------------+
-29-
IMP = 2
IMP Modem Throughput message = 3
Unused
Unused
A 16 bit number incremented at each collection interval (i.e. when a new throughput message is assembled). The HM will be able to detect lost or duplicate messages by checking the sequence numbers.
The password contains the sequence number of the polling message to which this message responds.
The time (in 640ms. units) at which the message was sent to the HM.
The IMP version number.
Data-time is the time (in 640ms. units) when this set of data was collected. (See Description.)
-30-
Prev-time is the time (in 640 ms. units) of the previous collection of data (and therefore, is the time when the data in this message began accumulating.)
This is the number of modems in the system.
This Modem is the number of the first modem reported in this message. Large systems that are unable to fit all their modem reports into a single packet may use this field to separate their message into smaller chunks to take advantage of single packet message efficiencies.
Modem throughput consists of three words of data
reporting packets and words output on each modem. The
first word counts packets output and the following two
count word throughput. The double precision words are
arranged high order first. (Note also that messages from
Honeywell type machines (316s, 516s and C30s) use a fifteen
bit low order word.) The first block reports output on the
modem specified by "This Modem". The following blocks
report on consecutive modems.
-31-
The host throughput message reports traffic statistics for each host in the system. The IMP will collect these data at regular intervals and save them awaiting a poll from the HM. If a period is missed by the HM, the new results simply overwrite the old. Two time stamps bracket the collection interval (data-time and prev-time) and are an indicator of missed reports. In addition, mess-time indicates the time at which the message was sent.
The host throughput format will hold only three hosts if packet boundaries are to be respected. A provision is made to split this into multiple packets by including a host number for the first entry in the packet.
The format of the host throughput message is as follows:
0 0 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+---------------+---------------+
0 | Mess-Time |
+---------------+---------------+
| Software Version Number |
+---------------+---------------+
| Data-Time |
+---------------+---------------+
| Prev-Time |
+---------------+---------------+
| Total Hosts | This Host |
+---------------+---------------+
5 : host :
. : throughput :
+---------------+---------------+
IMP = 2
IMP host Throughput message = 4
-32-
Unused
Unused
A 16 bit number incremented at each collection interval (i.e. when a new throughput message is assembled). The HM will be able to detect lost or duplicate messages by checking the sequence numbers.
The password contains the sequence number of the polling message to which this message responds.
The time (in 640ms. units) at which the message was sent to the HM.
The IMP version number.
Data-time is the time (in 640ms. units) when this set of data was collected. (See Description.)
Prev-time is the time (in 640 ms. units) of the previous collection of data (and therefore, is the time when the data in this message began accumulating.)
The total number of hosts in this system.
This host is the number of the first host reported in this
-33-
Each host throughput block consists of eight words in the following format:
+---------------+---------------+
| messages to network |
+---------------+---------------+
| messages from network |
+---------------+---------------+
| packets to net |
+---------------+---------------+
| packets from net |
+---------------+---------------+
| messages to local |
+---------------+---------------+
| messages from local |
+---------------+---------------+
| packets to local |
+---------------+---------------+
| packets from local |
+---------------+---------------+
Each host throughput message will contain several blocks of data. The first block will contain data for the host specified in First Host Number. Following blocks will contain data for consecutive hosts. All counters are single precision.
-34-
When a trap occurs, it is buffered in the TAC and sent as soon as possible. Trap messages are unsolicited. If traps happen in close sequence, several traps may be sent in one message.
Through the use of sequence numbers, it will be possible to
determine how many traps are being lost. If it is
discovered that many are lost, a polling scheme might be
implemented for traps.
A TAC trap message has the following form:
0 0 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+---------------+---------------+
0 | Version # |
+---------------+---------------+
1 : first :
. : trap :
. : data :
. +---------------+---------------+
. : additional :
. : trap :
. : data :
+---------------+---------------+
TAC = 3
TAC Trap Message = 1
Unused
-35-
Unused
Unused
A 16 bit number incremented each time a trap message is sent so that the HM can order the received trap messages and detect missed messages.
The version # of the TAC Software.
There can be several blocks of trap data in each message.
The format of the trap data is as follows:
+---------------+---------------+
| Size |
+---------------+---------------+
| Time |
+---------------+---------------+
| Trap ID |
+---------------+---------------+
: Trap :
: Data :
+---------------+---------------+
| Count |
+-------------------------------+
Size
Size is the number of 16 bit words in the trap, not counting the size field.
Time
The time (in 640ms. units) at which the trap occurred. This field is used to sequence the traps in a message and
-36-
Trap ID
This is (usually) the program counter at the trap. The ID identifies the trap, and does not have to be a program counter, provided that it uniquely identifies the trap.
Trap Data
The TAC returns data giving more information about the trap. There are usually two entries: the values in the accumulator and the index register at the occurrence of the trap.
Count
The TAC Counts repetitions of the same trap ID and reports this count here.
-37-
The status message gives a quick summary of the state of the TAC. Status of the most important features of the TAC are reported as well as the current configuration of the machine.
A TAC status message has the following form:
0 0 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
---------------+---------------+
0 | Version Number |
+---------------+---------------+
| Last Trap Message |
+---------------+---------------+
| Bit Flags |
+---------------+---------------+
| Free PDB count |
+---------------+---------------+
| Free MBLK count |
+---------------+---------------+
5 | # of TCP connections |
+---------------+---------------+
| # of NCP connections |
+---------------+---------------+
| INA A Register |
+---------------+---------------+
| INA X Register |
+---------------+---------------+
| INA B Register |
+---------------+---------------+
l0 | restart/reload |
+---------------+---------------+
| |
+ Crash +
| |
+ Data +
13 | |
+---------------+---------------+
-38-
TAC = 3
TAC Status Message = 2
Unused
Unused
A 16 bit number incremented each time a status message is sent.
Contains the sequence number from the polling message requesting this report.
The TAC's software version number.
Contains the sequence number of the last trap message sent to the HM. This will allow the HM to detect how many trap messages are being lost.
-39-
There are sixteen bit flags available for reporting the state of various switches (hardware and software) in the TAC. The bits are numbered as follows for purposes of the discussion below.
0 0 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | | | | | | | | | | | | | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The bit flags report the status of the following:
Bit Meaning
15 0 => DDT override off; 1 => override on.
11-14 0 => Sense Switch n is off; 1 => SSn on.
10 0 => Traps to remote monitor;
1 => Traps to console.
9 1 => Message generator on.
0-8 unused
The number of PDBs on the free queue.
The number of MBLKs on the free queue.
The number of open connections for each protocol.
These three fields report the values retained by an INA 1011 instruction in a C/30. This instruction returns micro- machine status and errors. In a #316, the fields are meaningless.
-40-
This word reports a restart or reload of the TAC
Value Meaning
1 restarted
2 reloaded
Crash data reports the circumstances surrounding an
unexpected crash. The first word reports the location of
the crash and the following two are the contents of the
accumulator and index registers.
-41-
The TAC throughput message reports statistics for the various modules of the TAC. The TAC will collect these data at regular intervals and save them awaiting a poll from the HM. If a period is missed by the HM, the new results simply overwrite the old. Two time stamps bracket the collection interval (data-time and prev-time) and are an indicator of missed reports. In addition, mess-time indicates the time at which the message was sent.
A TAC throughput message has the following form:
0 0 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+---------------+---------------+
0 | Mess-Time |
+---------------+---------------+
| Data-Time |
+---------------+---------------+
| Prev-Time |
+---------------+---------------+
| Version Number |
+---------------+---------------+
| Last Trap Message |
+---------------+---------------+
5 | Bit Flags |
+---------------+---------------+
| Free PDB count |
+---------------+---------------+
| Free MBLK count |
+---------------+---------------+
| # of TCP connections |
+---------------+---------------+
| # of NCP connections |
+---------------+---------------+ ----
10 | Host Input Throughput | ^
+---------------+---------------+ |
| Host Input Abort Count | |
+---------------+---------------+ |
| Host Input Garbled Count | |
+---------------+---------------+ |
| Host Output Throughput | 1822 info.
+---------------+---------------+ |
(continued)
-42-
+---------------+---------------+ |
| Host Output Abort Count | 1822 info.
+---------------+---------------+ |
15 | Host Down Count | v
+---------------+---------------+ ----
| # of datagrams sent | ^
+---------------+---------------+ |
| # of datagrams received | |
+---------------+---------------+ IP info.
| # of datagrams discarded | |
+---------------+---------------+ |
| # of fragments received | v
+---------------+---------------+ |
20 | # of fragments discarded | v
+---------------+---------------+ ----
| # of segments sent | ^
+---------------+---------------+ |
| # of segments received | |
+---------------+---------------+ |
| # of segments discarded | |
+---------------+---------------+ TCP info.
| # of octets sent | |
+---------------+---------------+ |
25 | # of octets received | |
+---------------+---------------+ |
| # of retransmissions | v
+---------------+---------------+ ----
TAC = 3
TAC Throughput Message = 3
Unused
Unused
-43-
A 16 bit number incremented at each collection interval (i.e. when a new throughput message is assembled). The HM will be able to detect lost or duplicate messages by checking the sequence numbers.
Contains the sequence number from the polling message requesting this report.
The time (in 640ms. units) at which the message was sent to the HM.
Data-time is the time (in 640ms. units) when this set of data was collected. (See Description.)
Prev-time is the time (in 640 ms. units) of the previous collection of data (and therefore, is the time when the data in this message began accumulating.)
The TAC's software version number.
Contains the sequence number of the last trap message sent to the HM. This will allow the HM to detect how many trap messages are being lost.
There are sixteen bit flags available for reporting the state of various switches (hardware and software) in the TAC. The bits are numbered as follows for purposes of the discussion below.
-44-
0 0 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | | | | | | | | | | | | | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The bit flags report the status of the following:
Bit Meaning
15 0 => DDT override off; 1 => override on.
11-14 0 => Sense Switch n is off; 1 => SSn on.
10 0 => Traps to remote monitor;
1 => Traps to console.
9 1 => Message generator on.
0-8 unused
The number of PDBs on the free queue.
The number of MBLKs on the free queue.
The number of open connections for each protocol.
These six fields report statistics which concern the
operation of the 1822 protocol module, i.e. the interface
between the TAC and its IMP.
These five fields report statistics which concern Internet Protocol in the TAC.
-45-
These six fields report statistics which concern TCP
protocol in the TAC.
-46-
The gateway supports parameters to set Throughput and Host traffic matrix measurements. The type of parameters and the parameter and data pairs are as follows:
Throughput - Type = 3
Parm. Description Control Data Word
----- ----------- -----------------
1 Start/Stop 0=Stop,1=Start
2 Collection Interval Time in 1 minute
ticks
Host Traffic Matrix - Type = 4
Parm. Description Control Data Word
----- ----------- -----------------
1 Start/Stop 0=Stop,1=Start
2 Collection Interval Time in 1 minute
ticks
3 HTM Switch Control Include Control
Protocols
-47-
When traps occur in the gateway they are buffered. At a fixed time interval (currently 10 seconds) the gateway will send any traps that are in the buffer to the monitoring center. The traps are sent as unsolicited messages.
A Gateway trap message has the following format:
0 0 0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Gateway Version # |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Size of Trap Entry | ;First Trap
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Time of Trap |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Trap ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Process ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| R0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| R1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| R2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| R3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(continued)
-48-
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| R4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| R5 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| R6 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Count of this Trap |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
.
.
.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Additional Trap reports |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Gateway = 4
Gateway Trap Message = 1
Unused
Unused
Unused
A 16 bit number incremented each time a trap message is sent so that the monitoring center can order the received trap messages and detect missed messages.
-49-
The software version number of the gateway sending the trap.
The remainder of the trap message consists of the trap reports. Each consists of the following fields:
Size of Trap Entry
The size in 16-bit words of the trap entry, not including the size field.
Time of Trap
The time in (in 1/60 sec. ticks) at which the trap occurred.
Trap ID
The number of the trap which is used to identify the trap.
Process ID
The identifier of the process that executed the trap.
R0-R6
The registers of the machine at the occurrence of the trap.
Count of this Trap
The number of times that this trap occurred.
-50-
The gateway status message gives a summary of the status of the gateway. It reports information such as version number of the gateway, buffer memory usage, interface status and neighbor gateway status.
A Gateway Status message has the following format:
-51-
0 1 1 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Patch Version Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Time Since Gateway Restart | ;in minutes
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Measurement Flags | ; Bit flags to indicate which
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ; measurements are on, 1= On
| Routing Sequence No. | ; Sequence # of last routing
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ; update sent
| Access Table Version # |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Load Sharing Table Ver. # |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Memory in Use |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Memory Idle |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Memory Free |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| # of Blks | ; Memory Allocation Info
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Size of 1st Block (in bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| # Allocated |
+-+-+-+-+-+-+-+-+
| # Idle |
+-+-+-+-+-+-+-+-+
.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Size of n'th Block (in bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| # Allocated |
+-+-+-+-+-+-+-+-+
| # Idle |
+-+-+-+-+-+-+-+-+
(continued)
-52-
+-+-+-+-+-+-+-+-+
| # of Ints. |
+-+-+-+-+-+-+-+-+
| Int 1 Flags | ;Interface 1 Status Flags
+-+-+-+-+-+-+-+-+ ; Bit 0 - 1=Up, 0=Down
; 1 - 1=Looped, 0=Not
+-+-+-+-+-+-+-+-+
| Buffers | ; # of buffers on write Queue
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Time since last Status Change | ;Time since last up/dwn change
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| # of Buffers Allocated |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Size for Interface |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface 1 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
.
.
+---------------+
| Int n Flags | ;Interface n Status Flags
+-+-+-+-+-+-+-+-+
| Buffers |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Time since last Status Change |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| # of Buffers Allocated |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Size for Interface |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface n Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| # Neighbors |
+-+-+-+-+-+-+-+-+
| UP/DN Flags | ;Bit flags for Up or Down
+-+-+-+-+-+-+-+-+ ; 0 = Dwn, 1 = Up
. ; MSB is neighbor 1
. ; (as many bytes as necessary)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Neighbor 1 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
.
.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Neighbor n Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-53-
Gateway = 4
Gateway Status Message = 2
Unused
Unused
Unused
A 16 bit number incremented each time a trap message is sent so that the monitoring center can order the received trap messages and detect missed messages.
The version number of the gateway sending the Status message.
The patch version number of the gateway.
The time in minutes since the gateway was last restarted or reloaded.
-54-
Flags that, if set, indicate which measurements are turned on. Current values are:
Bit 0 = Message Generator
1 = Throughput
2 = Host Traffic Matrix
3 = Access Control 1
4 = Access Control 2
5 = Load Sharing
6 = EGP in Gateway
The sequence number of the last routing update sent by this gateway.
The version number of the access control table.
The version number of the load sharing table.
The number of bytes of buffer memory that are currently in use.
The number of bytes of buffer memory that have been allocated but are currently idle.
The number of bytes of buffer memory that has not been allocated.
The next part of the status message contains information on
the buffer pools in the gateway. The fields are:
# of Blocks
-55-
Size of Block
The size of this block in bytes.
# Allocated
The number of blocks of this size that have been allocated.
# Idle
The number of blocks of this size that are idle.
The next part of the status message are fields that provide information about the gateway's interfaces. The fields are:
# of Interfaces
The number of network interfaces that the gateway has.
Interface Flags
Flags that indicate the status of this interface. The current values are:
Bit 0 - 1=Up/0=Down
1 - 1=Looped/0=Not Looped
Buffers
The numbers on this interfaces write queue.
Time Since Last Status Change
The time in minutes since this interface changed status (Up/Down).
# of Buffers Allocated
The number of buffers allocated for this interface.
Data Size for Interface
The buffer size required for this interface.
-56-
The Internet address of this interface.
The final part of the status message consists of information about this gateway's neighbor gateways. The fields are:
# of Neighbors
The number of gateways that are neighbor gateways to this gateway.
UP/DN Flags
Bit flags to indicate if the neighbor is up or down.
Neighbor Address
The Internet address of the neighbor gateway.
-57-
The gateway collects throughput statistics for the gateway, its interfaces, and its neighbor gateways. It collects them for regular intervals and will save them for collection via a Poll message from the Monitoring host. If they are not collected by the end of the next interval, they will be lost because another copy will be put into the saved area.
A Gateway Throughput message has the following format:
0 1 1 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Gateway Version Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Collection Time in Min |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of Interfaces |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of Neighbors |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of Host Unreachable | ; # of packets dropped because
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ; Host was Unreachable
| Number of Net Unreachable |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ; Net was Unreachable
; Interface Counters
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Packets Dropped on Input |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Count of IP Errors |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Count of Datagrams for Us |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Datagrams to be Forwarded |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Count of Datagrams Looped |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(continued)
-58-
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Count of Bytes Input |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Count of Datagrams From Us |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Count that were Forwarded |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Count of Local Net Dropped |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Count of Queue full Dropped |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Count of Bytes Output |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
.
.
.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Counters For Additional Interfaces |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
; Neighbor counters
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Neighbor Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Count of Routing Updates TO |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Count of Routing Updates FROM |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(continued)
-59-
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Pkts from US sent to/via Neig |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Pkts forwarded to/via Neighb |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Datagrams Local Net Dropped |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Datagrams Queue full Dropped |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Count of Bytes send to Neighbor |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
.
.
.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Counters for Additional Neighbor Gateways |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Gateway = 4
Gateway Throughput Message = 3
Unused
Unused
Unused
A 16 bit number incremented each time a trap message is sent so that the HM can order the received trap messages and
-60-
The software version number of the gateway sending the trap.
The time period in minutes in which the throughput data is to be collected.
The number of interfaces this gateway has.
The number of neighbor gateways this gateway has.
The number of packets dropped because the Host was
unreachable.
The number of packets dropped because the Network was unreachable.
The next part of the Throughput message contains counters
for the gateways interfaces. Each interface has the
following fields:
Interface Address
The Internet address of this interface.
Packets Dropped on Input
The number of packets on input to this interface because there were not enough buffers.
Count of IP Errors
The number of packets received with bad IP headers.
-61-
The number of datagrams received addressed to this gateway.
Datagrams to be Forwarded
The number of datagrams were not for this gateway and should be sent out another interface.
Count of Datagrams Looped
The number of datagrams that were received on and sent out of this interface.
Count of Bytes Input
The number of bytes received on this interface.
Count of Datagrams From Us
The number of datagrams that originated at this
gateway.
Count that were Forwarded
The number of datagrams that were forwarded to another gateway.
Count of Local Net Dropped
The number of packets that were dropped because of local network flow control restrictions.
Count of Queue full Dropped
The number of packets that were dropped because the output queue was full.
Count of Bytes Output
The number of bytes sent out on this interface.
-62-
The last part of the Throughput message are counts for each neighbor gateway. The fields are:
Neighbor Address
The Internet address of this neighbor gateway.
Count of Routing Updates TO
The number of routing updates sent to this neighbor gateway.
Count of Routing Updates FROM
The number of routing updates received from this neighbor gateway.
Pkts from US sent to/via Neig
The number of packets from this gateway sent to or via this neighbor gateway.
Pkts forwarded to/via Neighb
The number of packets forwarded to or via this neighbor gateway.
Datagrams Local Net Dropped
The number of datagrams dropped to this neighbor
gateway because of local network flow control
restrictions.
Datagrams Queue full Dropped
The number of datagrams dropped to this neighbor because the output queue was full.
Count of Bytes send to Neighbor
The number of bytes sent to this neighbor gateway.
-63-
The Host Traffic Matrix (HTM) message contains information about the traffic that flows through the gateway. Each entry consists of the number of datagrams sent and received for a particular source/destination pair.
A Gateway HTM message has the following format:
0 1 1 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Gateway Version Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Overflow counter |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Collection Time in Min |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of HTM entries |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP Source Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP Destination Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP Protocol | (unused) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Counter for SRC -> DST datagrams |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Counter for DST -> SRC datagrams |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
.
.
.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Additional HTM Reports |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-64-
Gateway = 4
Gateway HTM Message = 4
Unused
Unused
Unused
A 16 bit number incremented each time a trap message is sent so that the HM can order the received trap messages and detect missed messages.
The software version number of this gateway.
The number of HTM entries lost because the HTM buffer was full.
The time period in minutes in which the HTM data is being collected.
The number of HTM reports included in this message.
-65-
The remainder of the HTM message consists of the actual HTM entries. Each entry consists of the following fields:
IP Source Address
The source Internet address of the datagrams being counted.
IP Destination Address
The destination Internet address of the datagrams being counted.
IP Protocol
The protocol number of the datagrams.
Counter for SRC -> DST datagrams
The number of datagrams sent in the Source to
Destination address direction.
Counter for DST -> SRC datagrams
The number of datagrams sent in the Destination to Source address direction.
-66-
The Routing message contains information about routes the gateway has to the networks that make up the Internet. It includes information about its interfaces and its neighbor gateways.
A Gateway Routing message has the following format:
0 1 1 2 3 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| # of Ints. |
+-+-+-+-+-+-+-+-+
| UP/DN Flags | ;Bit flags for Up or Down
+-+-+-+-+-+-+-+-+ ; 0 = Dwn, 1 = Up
. ; MSB is interface 1
. ; (as many bytes as necessary)
.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface 1 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
.
.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface n Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| # Neighbors |
+-+-+-+-+-+-+-+-+
| UP/DN Flags | ;Bit flags for Up or Down
+-+-+-+-+-+-+-+-+ ; 0 = Dwn, 1 = Up
. ; MSB is neighbor 1
. ; (as many bytes as necessary)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Neighbor 1 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
.
.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Neighbor n Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(continued)
-67-
+-+-+-+-+-+-+-+-+
| # of Networks |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network 1 # | | | ; 1, 2, or 3 bytes
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Distance |
+-+-+-+-+-+-+-+-+
| Neighbor # |
+-+-+-+-+-+-+-+-+
.
.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Network n # | | | ; 1, 2, or 3 bytes
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Distance |
+-+-+-+-+-+-+-+-+
| Neighbor # |
+-+-+-+-+-+-+-+-+
Gateway = 4
Gateway Trap Message = 6
Unused
Unused
Unused
A 16 bit number incremented each time a trap message is sent so that the HM can order the received trap messages and detect missed messages.
-68-
The software version number of the gateway sending the trap.
The first part of the routing message contains information about the gateway's interfaces. There is data for each interface. The fields are:
# of Interfaces
The number of interfaces that this gateway has.
UP/DN Flags
Bit flags to indicate if the Interface is up or down.
Interface Address
The Internet address of the Interface.
The next part of the routing message contains information about this gateway's neighbor gateways. The fields are:
# of Neighbors
The number of gateways that are neighbor gateways to this gateway.
UP/DN Flags
Bit flags to indicate if the neighbor is up or down.
Neighbor Address
The Internet address of the neighbor gateway.
The last part of the routing message contains information
about this gateway's routes to other networks. This
includes the distance to each network and which neighbor
gateway is the route to the network. The fields are:
-69-
The number of networks that are reachable from this gateway.
Network #
The network number of this network. This is the network part of the Internet address and may be one, two, or three bytes in length depending on whether it is a Class A, B, or C address.
Distance
The distance in hops to this network. Zero hops means that the network is directly connected to this gateway. A negative number means that the network is currently unreachable.
Neighbor #
The neighbor gateway that is the next hop to reach this
network. This is an index into the previous
information on this gateway's neighbor gateways. This
field is only valid if the Distance is greater than
zero.
-70-