JPH02230840A - How to test network addresses - Google Patents

Abstract

PURPOSE:To facilitate the distinguishment of an active system and a standby system between plural servers having the same function by allowing each terminal station to detect uniquely the presence of terminal stations having the same address in a network. CONSTITUTION:A terminal station 3-1 includes an address (group address and function address or the like) assigned to its own station to an address test frame(ATF) 4 and broadcasts the result to the entire area in a network. A terminal station 3-2 receiving a frame checks the rationality of an address and decides the operation of its own station such as the reply of a response depending on the check result. Thus, the abnormality of address allowing duplication in the network such as a function address or a group address assigned to terminal stations 3-1 and 3-2 is detected.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for checking the rationality of addresses of network terminal stations. [Prior Art] Conventional methods include methods described in the following documents.

ANI/IEE Standard (
ANSI/IEEE Std) 802.5/1985
ISO/DP 8802/5 “Token Ring Access Methods and Physical Layer Specifications”
Access Method and Physica
According to this document, a terminal station joining a network (ring) first performs a validity check on its own address. (D A '1') and goes around the ring and returns l) This is done by checking the flag indicating the reception status of the destination party on the AT.
The AT receives an A indicating that the other station has recognized the frame.
(Address Recognized: Address Re
There is a C (copied) bit that indicates that the data has been captured. If there are multiple terminal stations with the same address in the same ring, this will be reflected in the A and C bits of IJAT. L)
The A'r source terminal station checks the A and C bits. The following document describes a communication method in a network consisting of multiple rings that can detect duplicate addresses. Draft Maddendam 2 ANI/IEE Standard (Draft Addend
um to ANSI/IHHI {Std)802.
5-1985 “Token Lying MAC & Phy Sp
ecificationEnhancament for
rMultipla-Ring Networks)
"Sept. 23, 1988 According to this document, the source terminal station obtains a communication route to the other end station by broadcasting communication to the entire network, but this is because the other party's address is connected to the network. It assumes that the address is unique.It does not mention the means to protect this condition, nor does it mention countermeasures when there are duplicate addresses in the network.As a method for detecting duplicate addresses in the network. There is a method described in the following document: “Text for IOS/DIS8
802-2.2 Logical link control (T
extfor ISO/DI8 8802-2.
2. Logical Link Control
)"180/"1'C97/SC6 N4609.1
987-10-02 According to the document, the originating station of the duplicate address test sets its own unique address (SA) in the DA, and uses XID: Exchange Identification.
n) Broadcast a test frame containing the functionality into the network. The receiving station of the frame, that is, the station having an address equal to the SA, uses the function Xll) to:
A response is returned to the station that sent the frame. The sending station of the test frame can detect an address duplication error based on the response. In this document, duplication abnormalities of addresses specific to each terminal station are detected by the above-mentioned means, but there is no mention of addresses that are allowed to be duplicated, such as functional addresses and group addresses. Any station that detects a duplication abnormality will immediately leave the network. [Problems to be Solved by the Invention] The purpose of the present invention is to detect anomalies in addresses that are allowed to overlap within the network, such as functional addresses and group addresses assigned to each terminal station. Furthermore, the purpose is to prioritize terminal stations that have the same address. In addition, the function address (Functiona
l Address) is an address set for each function of the terminal station, such as a parameter server or an error monitor, and a group address (Group Address).
address) is an address set for each group of terminal stations with the same attributes. According to the present invention, it is possible to prioritize, for example, determine the active system or backup system among multiple servers having the same function. [Means for resolving the problem] In order to achieve the above object, in the present invention, the terminal station includes the address assigned to itself (group address, functional address, etc.) in the address test frame, and Broadcast to the entire area. The terminal station that receives the frame checks the validity of the address and decides its own action, such as returning a response, based on the check results. [Operation] The source terminal station that sends out the address test frame (A 'l'F') may set its own address in the DA of the ATF, or set the DA as the broadcast address and set the information part (INFO part, described later). ) may be set to the own address. In the previous discussion, when the DA has multiple types of self-addresses (for example, both group and functional addresses), the number of ATF transmissions increases, but only the terminal station addressed to the DA, that is, the terminal station with duplicate addresses, needs to receive it. While the load on the receiving end can be reduced6, in the latter case, the ATF only needs to be sent once, but all end stations receive the ATF.

The terminal station that receives the ATF checks the validity of the address and responds with the check result to the terminal station indicated by the source address (SA) of the ATF.

When returning a response only when it is determined to be unreasonable (for example, detection of a duplicate address), the sender of the ATF will determine the rationality of its own address based on the timeout of the response. In addition to checking rationality, priority (for example, the result of competition using the size relationship of address values)
Information can also be responded to. [Examples] Examples of the present invention will be described below. Figure 1 shows an example of a network configuration to which the present invention is applied. 1 (1-1~1-
5) is a ring network, 2 (2-1 to 2-3) is an interruption device, and 3 (3-1 to 3-2) is a communication terminal station.
In this figure, terminal station 3-2 is newly connected to ring 1-5, address test frame (ATF) 4 is sent out, and
"rF4 is broadcast throughout the network." Figure 2 shows the frame structure of ATF4.11 is the start delimiter (SD).12 is the function type (FC).13
is the destination address (DA), and 14 is the source address (S
A), 15 is transfer information (INFO). 16 is the FCS check code (FCS). 17 is the end delimiter. The frame in question is ATF, that is, it can be distinguished from other communication frames by F' C 1 2. When relay device 2 receives A7rF4, it sends the A "l'F' 4 to all ring networks connected to itself.
will be relayed. After ATF4's ring trip, the ATF
' 4 from the ring, relay device 2
SAl4 of TF4 may be stored in memory. In addition, in freely connected networks, for example, in a configuration in which multiple ring networks are connected in a mesh pattern, ATF
It is also possible to include information on the maximum allowable number of relays in INFO15 of the ATF and have each relay device update and check this information so that the information does not circulate forever.

Figure 3 shows the operation of terminal stations 3-2 newly connected to rings 1-5. First, ATF is formed (100). Here, an address assigned to the own terminal station, such as a terminal station group address (Group Address) or a functional address (Functional Address), etc., is set in DAL3. Set the response monitoring timer (1
10), Send ATF (120). Wait for reception of response (130). Due to the reception timeout (1 4 0), the terminal station that has the address set in DA is determined to be the only terminal station, and steady state (normal) communication is started (1 5
0). On the other hand, if it receives a response and determines that its own address is unreasonable or has low priority, it takes measures such as leaving its own station from the network or placing it in a standby state (16
0). Figure 4 shows the operation of ATF4 during reception. Since the address assigned to the sending terminal station is set in DA13. The terminal station that receives ATF4 will be the terminal station that has a duplicate address. Check the reasonableness of the address (200)
, a response is returned to the terminal station of SA14 of A'rF4 which is judged to be unreasonable (210). There are several ways to return the response, such as returning multiple identical responses in consideration of reliability. Conceivable. The structure of the response frame may be one in which DA13 and SAl4 of ATF4 are replaced. Also, there may be overlaps. For example, for functional addresses, etc., determine the priority (for example, by comparing the size of the terminal-specific address)
The result may always be sent back as a response. If a response is always returned, use the test command ('rest Command: TEST) or exchange identification command (Exchange Identification) described in the following document.
n: X ID) may be used. ANSI/IEEE Std 802.2-198
5ISO/DIS 8802/2 “Logical Link Control (LogicalL
Ink Control)" Let us consider the case where priority control using functional addresses etc. is performed in a single ring as described in the prior art. It is possible to use the A bit. After connecting to the ring, set the functional address in DA. ATF, which has been connected to the ring first.If a terminal station with the address is connected to the ring, it will be reflected in the A bit of the ATF.Using this operation specification, for example, the terminal station that connected to the ring first When multiple rings are connected to form one ring, it is possible to perform contention control such as obtaining high priority. In this case, the priority may be reset by comparing the unique addresses of the terminal stations as described above. Figure 5 shows an example of application of the present invention to another network configuration. - It is a network and is connected to the ring network 1 via the relay device 2. A terminal station 3- that newly joins the network
4 makes DA the broadcast address and INF
The address assigned to the own terminal station is included in O and sent. A situation is shown in which the terminal station 3-1 detects an unreasonable address and sends back a response 6 to that effect. A terminal station that receives an ATF and determines that the address is unreasonable does not have to send a response. A'
It is also possible to give higher priority to the terminal station that sent l'F. Figure 6 shows the application of the present invention to a satellite communication network. 20 is a communication satellite, 21 (21-1 to 21-4
) is a ground station, 22 is an address test frame or packet containing the station address, and 23 is a response to the frame. A situation is shown in which the ground station 21-1 and the ground station 21-4 have the same address, for example, and the ground station 21-4 detects an unreasonable address and returns a response 33 to that effect. [Effects of the Invention] According to the present invention, each terminal station can independently detect the existence of a terminal station with the same address in the network.
Priority control among these terminal stations can be performed through distributed control of the terminal stations. This makes it easy to distinguish, for example, between multiple servers with the same functionality, whether they are scientific or standby. In addition, not only terminal station individual addresses but also functional addresses, group addresses, etc.
The network has a unique address system.
There is an effect that can be achieved through distributed control between each terminal station.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the network configuration of an embodiment of the present invention, and FIG. 2 is an address test frame (AT
FIG. 3 is a flowchart showing an example of address test operation of a terminal station newly connected to the network, FIG. 4 is a flowchart showing an example of ATF reception operation according to the test, and FIG. 5 is an explanatory diagram showing the configuration of F). and FIG. 6 are block diagrams and schematic diagrams showing the network configuration of another embodiment of the present invention. 4. Address test frame (ATF); 6. Address test response. Fig. Rikizu Heron ■ Tomarizu

Claims (1)

[Claims] 1. A terminal station address testing method in a communication network including a plurality of terminal stations, wherein the terminal station (test station) uses its own functional address or group address as a destination address (DA). The test station transmits a test frame set to A method for testing a network address, characterized in that the operation of its own station is determined. 2. The network according to claim 1, wherein the test station sets the DA to a broadcast address and transmits a test frame containing the address assigned to the test station. - How to test addresses. 3. A terminal station address test method in a communication network including multiple terminal stations, in which the terminal station sets its own address to D.
A network address testing method, characterized in that a test frame set to A is sent out, and a terminal station that receives the test frame determines its own operation based on the result of checking the test address.