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CloudEngine 12800 and 12800E V200R005C10 Configuration Guide - IP Service

This document describes the configurations of IP Service, including IP address, ARP, DHCP, DNS, UDP Helper, IP performance optimization, IPv6, DHCPv6, IPv6 DNS and IPv6 Transition Technology.

Configuring the ARP Resource Allocation Mode

Configuring the ARP Resource Allocation Mode

Context

For the device, learned ARP information are saved into EEDB entries of the chip. ARP resource allocation modes are classified depending on the mode in which ARP information is stored into EEDB entries:

  • global

    In Figure 2-18, the global mode indicates that ARP information is identified based on the key composed of the IP address, logical interface index, and physical interface index. ARP information is stored on all chips based on the same resource index, that is, ARP information stored on each chip is the same.

    In this mode, the maximum number of ARP resources of the device refers to that of the chip with minimum specifications among all chips.

    Figure 2-18 global mode

  • local

    In Figure 2-19, the local mode indicates that ARP information is identified based on the key composed of the IP address, logical interface index, and physical interface index. ARP information is stored only on the chip where the outbound interface is located, that is, ARP information stored on each chip is different.

    In local mode, the maximum number of ARP resources of the device is relevant to the chip where the outbound interface is located.
    • If all outbound interfaces corresponding to ARP information are located on the same chip, the maximum number of ARP resources of the device is that of the chip.
    • If all outbound interfaces corresponding to ARP information are located on different chips, the maximum number of ARP resources of the device is the sum of ARP resources of all chips.
    Figure 2-19 local mode

  • extend

    In Figure 2-20, the extend mode indicates that ARP information is identified based on the key composed of the highest 44 bits of a MAC address. ARP information is stored on all chips based on the same resource index, that is, ARP information stored on each chip is the same. The difference between extend and global modes is that ARP information corresponding to contiguous MAC addresses is aggregated in extend mode. That is, ARP information with the same highest 44 bits of a MAC address corresponds to the same ARP resource.

    In local mode, the maximum number of ARP resources of the device depends on whether MAC addresses are contiguous.
    • If MAC addresses corresponding to ARP information is noncontiguous, the maximum number of ARP resources of the device refers to that of the chip with minimum specifications among all chips.
    • If MAC addresses corresponding to ARP information is contiguous, the maximum number of ARP resources of the device refers to that of the chip with minimum specifications among all chips multiplied by 16.
    Figure 2-20 extend mode

Procedure

  1. Run system-view

    The system view is displayed.

  2. Run arp resource-mode { global | local | extend }

    The ARP resource allocation mode is configured.

    By default, the ARP resource allocation mode is global mode and that of the CE12800E configured with ED-E, EG-E, and EGA-E series cards is extend mode.

    • The CE12800E configured with FD-X series cards does not support this command.
    • The CE12800E configured with ED-E, EG-E, and EGA-E series cards does not support the local parameter.
    • The local mode has high requirements for network deployment. Exercise caution when you use this mode. To use this mode, contact technical support personnel.

    • If the extended Layer 3 forwarding resource mode of a card on the CE12800E configured with ED-E, EG-E, and EGA-E series cards is ipv4-ipv6 or large-ipv4, the ARP resource allocation mode cannot be set to extend. If the ARP resource allocation mode is extend, the extended Layer 3 forwarding resource mode of a card on the CE12800E configured with ED-E, EG-E, and EGA-E series cards cannot be set to ipv4-ipv6 or large-ipv4.

  3. Run commit

    The configuration is committed.

    After configuring the ARP resource allocation mode, you must run the reboot command to restart the device to make the configuration take effect.