WO2016019763A1

WO2016019763A1 - Extension method and apparatus for address resolution protocol table and storage medium

Info

Publication number: WO2016019763A1
Application number: PCT/CN2015/081700
Authority: WO
Inventors: 焦赵云
Original assignee: 中兴通讯股份有限公司
Priority date: 2014-08-05
Filing date: 2015-06-17
Publication date: 2016-02-11
Also published as: CN105323175A

Abstract

Disclosed is an extension method for an address resolution protocol (ARP) table. A CPU obtains an ARP table and provides an IP address of the ARP table in a host routing table of a switching chip; and when a hash conflict happens to the host routing table, the IP address of the ARP table having the hash conflict is provided in a sub-network routing table of the switching chip. Also disclosed at the same time are an extension apparatus for an address resolution protocol table and a storage medium.

Description

Method and device for expanding address resolution protocol table, storage medium

Technical field

The present invention relates to network routing technologies, and in particular, to an extended method and apparatus for an address resolution protocol (ARP) table, and a storage medium.

Background technique

With the rapid development of metropolitan area networks, the bandwidth of access and aggregation network equipment is increasing, and operators are demanding more and more users accessing one device. In addition to Layer 2 (L2) access, the access mode also has Layer 3 (L3) access. For the L3 access mode, access devices such as DSLAMs, PONs, and MAN switches need to use switch chips for data aggregation and L3 forwarding. Due to the increasing number of access users, the capacity of the switch chip to store ARP tables cannot meet this requirement. The current practice is generally to replace the switch chip with a larger ARP table capacity, but this method is limited by two conditions: First, whether the chip manufacturer can provide such a product in time, and second, the cost of the chip will be high.

Summary of the invention

In order to solve the existing technical problems, the present invention mainly provides an extended method and device for an address resolution protocol table, and a storage medium.

The technical solution of the present invention is implemented as follows:

The present invention provides an extended method of an ARP table, the method comprising:

The CPU obtains the ARP table, and sets the networking protocol (IP) address of the ARP table to the host routing table of the switch chip;

When a hash collision occurs in the host routing table, the CPU sets the IP address of the hash conflicting ARP table to the subnet routing table of the switching chip.

In the above solution, the obtaining the ARP table by the CPU includes: the CPU receiving the ARP packet, The ARP learning is performed. The ARP learning is to establish an ARP table by establishing a mapping relationship between the IP address, the next hop information, and the interface.

In the above solution, the method further includes: after the CPU sets the IP address of the hash conflicting ARP table to the subnet routing table of the switch chip, and further sets a fully matched subnet mask for the IP address, where the subnet The lookup table of the routing table uses a three-state content addressing memory (TCAM) lookup table.

In the above solution, the method further includes: setting, by the CPU, a threshold, when the number of IP addresses of the ARP table set to the subnet routing table reaches the threshold, the other IP addresses of the ARP table are no longer set to the subnet routing table. in.

In the above solution, the method further includes: the CPU marking the flag of the IP address of the ARP table set to the host routing table as a host; setting a flag of the IP address of the ARP table set to the subnet routing table For subnets.

In the above solution, the method further includes: when performing a host route lookup on the data packet, the switch chip preferentially searches for the IP address of the host routing table, and if found, directly forwards the data packet according to the found IP address, if If not found, the subnet routing table is matched with the longest IP mask. If it is found, the packet is directly forwarded according to the found IP address. If not found, the packet is discarded or sent to the CPU. .

In the foregoing solution, the method further includes: when the ARP entry is aged or deleted, the CPU first checks the flag of the IP address of the aging or deleted ARP entry, and if it is the host, searches for and deletes the host routing table from the switch chip. IP address entry of the IP address; if it is subnet, find and delete the IP address of the IP address from the subnet routing table of the switch chip.

The present invention provides an extension device of an address resolution protocol table, which includes: a CPU and a switch chip;

The CPU is configured to obtain an ARP table, and set an IP address of the ARP table to a host routing table of the switch chip; when a hash collision occurs in the host routing table, set an IP address of the ARP table of the hash conflict to the sub-switch of the switch chip. In the network routing table;

A switch chip configured to provide a host routing table and a subnet routing table.

In the above solution, the CPU is further configured to set a threshold. After the number of IP addresses of the ARP table set to the subnet routing table reaches the threshold, the other IP addresses of the ARP table are no longer set to the subnet route. In the table.

In the above solution, the CPU is further configured to mark the flag of the IP address of the ARP table set to the host routing table as host; and mark the IP address of the ARP table set to the subnet routing table as subnet.

A storage medium having stored therein a computer program configured to perform the aforementioned method of extending an Address Resolution Protocol (ARP) table.

The embodiment of the present invention provides an extended method and device for an address resolution protocol table, and a storage medium. The CPU obtains an ARP table, and sets an IP address of the ARP table to a host routing table of the switch chip; when the host routing table occurs When the hash conflicts, the IP address of the ARP table of the hash conflict is set to the subnet routing table of the switch chip. In this way, the capacity of the IP address of the ARP table stored in the switch chip can be greatly improved, and the problem that the network failure of the host host routing IP address hash conflict is solved.

DRAWINGS

1 is a schematic flowchart 1 of a method for implementing an address resolution protocol table according to an embodiment of the present invention;

2 is a schematic flowchart of aging or manually deleting an ARP entry according to an embodiment of the present invention;

3 is a schematic structural diagram of an apparatus for implementing an address resolution protocol table according to an embodiment of the present invention;

FIG. 4 is a second schematic flowchart of a method for implementing an address resolution protocol table according to an embodiment of the present invention.

detailed description

The switch chip generally has a host routing table and a subnet routing table. The host routing table is used to store the IP address and the next hop index of the ARP table, and the subnet routing table is used to store the subnet IP address prefix and the next hop. index. The host routing table generally uses the hash algorithm, and the subnet routing table generally uses the Ternary Content Addressable Memory (TCAM) because it needs to preferentially perform the longest route matching. The TCAM has the advantages of fast searching speed and simple operation. But at the same time it also has obvious shortcomings: high cost, high power consumption and complex routing updates. Although the host routing table in the switch chip is relatively large, it is easy to conflict by using the hash algorithm; although the subnet routing table is relatively small, the search is accurate. According to the characteristics of these two tables, an extension method and device of the address resolution protocol table are proposed.

In the embodiment of the present invention, the CPU obtains the ARP table, and sets the IP address of the ARP table to the host routing table of the switch chip. When the host routing table has a hash conflict, the IP address of the ARP table of the hash conflict is set to the exchange. The subnet routing table of the chip. In this way, the capacity of the IP address of the ARP table stored in the switch chip can be greatly increased.

The invention will be further described in detail below with reference to the drawings and specific embodiments.

An embodiment of the present invention implements an extension method of an address resolution protocol table. As shown in FIG. 1 , the method mainly includes the following steps:

Step 101: The CPU obtains an ARP table.

Step 102: The CPU sets an IP address of the ARP table to a host routing table of the switch chip.

Step 103: When a hash collision occurs in the host routing table, the CPU sets the IP address of the ARP table of the hash conflict to the subnet routing table of the switching chip.

In the above steps, the setting of the host routing table by the CPU or the setting of the subnet routing table by the CPU may be: the CPU writes the register of the host chip routing table or the subnet routing table of the switching chip through the PCI bus. operating.

In the step 101, the CPU obtains an ARP table by using an ARP protocol or a Dynamic Host Configuration Protocol (DHCP), where the ARP table includes an IP address, a next hop information, and a mapping relationship between the interfaces. In step 101, the CPU receives an ARP packet and performs ARP learning. The ARP learning is to establish an IP address and a next hop. The mapping relationship between the information and the interface forms an ARP table.

In the step 103, the CPU determines that a hash collision occurs in the host routing table according to the received setup failure message, and the setting failure message is that the number of IP addresses having the same hash index in the host routing table exceeds the hash bucket depth. When the chip feeds back the message, the hash bucket depth may generally be 8.

As an implementation manner, after the CPU sets the IP address of the hash conflicting ARP table to the subnet routing table of the switch chip, it is also required to set a fully matched subnet mask for the IP address, and the subnet mask. For 32-bit (IPV4) or 128-bit (IPV6), the look-up table of the subnet routing table adopts the TCAM lookup table.

The subnet routing table cannot be used to store the IP address of the ARP table. Therefore, you need to set a threshold. When the number of IP addresses in the ARP table of the subnet routing table reaches the threshold. The other IP addresses of the ARP table are no longer set to the subnet routing table.

As an implementation manner, for the IP address of the ARP table set to the host routing table, the CPU marks the flag of each IP address as a host; for the IP address of the ARP table set to the subnet routing table, The CPU marks the flag of each IP address as a subnet.

When performing a host route lookup on a data packet, the switch chip preferentially searches for the IP address of the host routing table. If it finds, it directly forwards the data packet according to the found IP address. If not, the subnet route is obtained. The table performs a matching lookup of the longest IP mask. If it finds, it forwards the packet directly according to the found IP address. If it is not found, the packet is discarded or sent to the CPU.

As shown in Figure 2, the steps for aging or deleting an ARP entry include:

Step 201: The ARP entry is aged or deleted.

Step 202: The CPU first checks the flag of the IP address of the aging or deleted ARP entry, and if it is the host, searches for and deletes the IP entry of the IP address from the host routing table of the switch chip, and returns a success message;

Step 203: If it is a subnet, find and delete an IP entry of the IP address from the subnet routing table of the switch chip, and return a success message;

Step 204: If both types are not, a failure message is returned.

In order to achieve the above method, the present invention further provides an apparatus for extending an address resolution protocol table. As shown in FIG. 3, the apparatus includes: a CPU 31 and a switch chip 32;

The CPU 31 is configured to obtain an ARP table, and set an IP address of the ARP table to a host routing table of the switch chip. When a hash collision occurs in the host routing table, set an IP address of the ARP table of the hash conflict to the switch chip. Subnet routing table;

The switch chip 32 is configured to provide a host routing table and a subnet routing table.

The ARP table is obtained by the CPU 31. The CPU 31 receives the ARP packet and performs ARP learning. The ARP learning is to establish an ARP table by establishing an mapping relationship between the IP address, the next hop information, and the interface.

As an implementation, the CPU 31 is further configured to set a fully matched subnet mask for the IP address set in the subnet routing table, the subnet mask being 32 bits (IPV4) or 128 bits (IPV6) The manner of checking the subnet routing table adopts the TCAM lookup table.

As an implementation manner, the CPU 31 is further configured to set a threshold. After the number of IP addresses of the ARP table set to the subnet routing table reaches the threshold, the other IP addresses of the ARP table are no longer set to the sub-address. In the network routing table.

As an implementation manner, the CPU 31 is further configured to mark the IP address of each ARP table as the IP address of the ARP table set to the host routing table, and the IP address of the ARP table set to the subnet routing table. Mark the flag of each IP address as subnet.

The switch chip 32 is further configured to perform an IP address matching search on the host routing table preferentially when performing host route lookup on the data packet. If found, the data packet is directly forwarded according to the found IP address, if not found. To, the matching lookup of the longest IP mask is performed on the subnet routing table. If found, the data packet is directly forwarded according to the found IP address, if not If found, the packet is discarded or sent to the CPU 31;

The CPU 31 is further configured to: when the ARP entry is aged or manually deleted, first check the flag of the IP address of the aging or deleted ARP entry, and if it is the host, look up and delete the packet from the host routing table of the switch chip. IP address entry of the IP address; if it is subnet, it searches for and deletes the IP address of the IP address from the subnet routing table of the switch chip; if neither type is true, it returns a failure.

FIG. 4 is a specific example of an extension method of an address resolution protocol table according to the present invention, which includes the following steps:

Step 401: The CPU receives the ARP packet, performs ARP learning, and obtains an ARP table.

Step 402: The CPU sets the IP address of the ARP table to the host routing table of the switch chip.

Step 403: The CPU determines whether the host routing table has a hash conflict, if yes, step 404 is performed, if no, step 407 is performed;

Step 404: The CPU sets the IP address of the ARP table of the hash conflict to the subnet routing table of the switch chip.

Step 405: The CPU determines whether the setting is successful. If yes, step 406 is performed, and if not, a failure message is returned;

Step 406: The CPU marks the IP address of the ARP table set to the host routing table as host, and marks the IP address of the ARP table set to the subnet routing table as subnet, and returns a success message;

Step 407: The CPU marks the IP address of the ARP table set to the host routing table as host, and returns a success message.

In the embodiment of the present invention, by setting the IP address of the ARP table to the host routing table and the subnet routing table of the switch chip, the capacity of the IP address of the ARP table stored in the switch chip is improved, and the host host routing IP address hash can be solved. The problem of network failure after the conflict.

Embodiments of the present invention also describe a storage medium in which a computer is stored A program configured to perform an extension method of an Address Resolution Protocol (ARP) table described in the foregoing embodiments.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in Within the scope of protection of the present invention.

Industrial applicability

In the present invention, the ARP table is obtained by the CPU, and the IP address of the ARP table is set in the host routing table of the switch chip; when a hash collision occurs in the host routing table, the IP address of the ARP table in which the hash conflicts is set. Set to the subnet routing table of the switch chip. In this way, the capacity of the IP address of the ARP table stored in the switch chip can be greatly improved, and the problem that the network failure of the host host routing IP address hash conflict is solved.

Claims

An extended method of an Address Resolution Protocol (ARP) table, the method comprising:

The CPU obtains the ARP table, and sets the networking protocol (IP) address of the ARP table to the host routing table of the switch chip;

When a hash collision occurs in the host routing table, the CPU sets the IP address of the hash conflicting ARP table to the subnet routing table of the switching chip.
The method of claim 1 , wherein the obtaining the ARP table by the CPU comprises: the CPU receiving an ARP packet, and performing ARP learning, where the ARP learning is to establish an IP address, a next hop information, and an interface. The mapping relationship between the two forms an ARP table.
The expansion method according to claim 1, wherein the method further comprises: after the CPU sets the IP address of the hash conflicting ARP table to the subnet routing table of the switch chip, and further sets a fully matched sub-portion to the IP address. The netmask, the lookup mode of the subnet routing table adopts a three-state content addressing memory (TCAM) lookup table.
The expansion method according to claim 1, wherein the method further comprises: the CPU setting a threshold, and after the number of IP addresses of the ARP table set to the subnet routing table reaches the threshold, the other ARP table is no longer used. The IP address is set to the subnet routing table.
The expansion method according to claim 1, wherein the method further comprises: the CPU marking a flag of an IP address set to an ARP table of the host routing table as a host; setting the packet to the subnet routing table The flag of the IP address of the ARP table is marked as a subnet.
The expansion method according to claim 1, wherein the method further comprises: when the host performs route lookup on the data packet, the switch chip preferentially searches for the IP address of the host routing table, and if found, searches according to the search result. The IP address directly forwards the data packet. If not found, the longest IP mask matching search is performed on the subnet routing table. If found, the data packet is directly forwarded according to the found IP address. If not, the packet is not directly found. Drop or send the packet to the CPU.
The expansion method according to claim 5, wherein the method further comprises: when the ARP entry is aged or deleted, the CPU first checks the flag of the IP address of the aged or deleted ARP entry, and if it is the host, the host from the switch chip The IP address of the IP address is searched for and deleted in the routing table. If it is a subnet, the IP address of the IP address is searched for and deleted from the subnet routing table of the switch chip.
An expansion device of an address resolution protocol table, the device comprising: a CPU and a switch chip; wherein

The CPU is configured to obtain an ARP table, and set an IP address of the ARP table to a host routing table of the switch chip; when a hash collision occurs in the host routing table, set an IP address of the ARP table of the hash conflict to the sub-switch of the switch chip. In the network routing table;

A switch chip configured to provide a host routing table and a subnet routing table.
The expansion device according to claim 8, wherein the CPU is further configured to set a threshold, and when the number of IP addresses of the ARP table set to the subnet routing table reaches the threshold, the ARP table is no longer The other IP addresses are set to the subnet routing table.
The expansion apparatus according to claim 8, wherein said CPU is further configured to mark a flag of an IP address of an ARP table set to a host routing table as host; an IP address of an ARP table to be set to a subnet routing table The flag is marked as subnet.
A storage medium storing a computer program configured to execute the method of extending an address resolution protocol (ARP) table according to any one of claims 1 to 7.