No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

Configuration Guide - IP Service

CloudEngine 8800, 7800, 6800, and 5800 V200R002C50

This document describes the configurations of IP Service, including IP address, ARP, DHCP, DNS, IP performance optimization, IPv6, DHCPv6, and IPv6 DNS.
Rate and give feedback:
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
IP Address Assignment and Renewal

IP Address Assignment and Renewal

IP Address Assignment Sequence

A DHCP server assigns an IP address to a client in the following sequence:

  • IP address that is in the database of the DHCP server and is statically bound to the MAC address of the client
  • IP address that has been assigned to the client before, that is, IP address in the Requested IP Addr Option of the DHCP Discover message sent by the client
  • IP address that is first found when the DHCP server searches the DHCP address pool for available IP addresses
  • Valid IP address among expired IP addresses and conflicting IP addresses if the DHCP address pool has no available IP address. If all the IP addresses are in use, an error is reported.

Method of Preventing Repeated IP Address Assignment

Before assigning an IP address to a client, a DHCP server needs to ping the IP address to avoid an address conflict.

Using the ping command, you can check whether a response to the ping packet is received within the specified period. If no response to the ping packet is received, the DHCP server keeps sending ping packets to the IP address to be assigned until the number of sent ping packets reaches the maximum value. If there is still no response, this IP address is not in use, and the DHCP server assigns the IP address to the client. (This is implemented based on RFC 2132.)

IP Address Reservation

DHCP supports IP address reservation for clients. The reserved IP addresses can be those in the address pool or not. If an address in the address pool is reserved, it is no longer assignable. Addresses are usually reserved for DNS servers.

Method of IP Address Releasing and Lease Renewal on a PC

A PC (DHCP client) must release the original IP address before obtaining a new IP address.

  • Releasing the original IP address

    Commands for renewing the lease time of an IP address vary depending on the operating system. You can use either of the following methods to renew the lease time of an IP address:

    • Run the ipconfig /release command on the Windows 7 operating system of the PC to release the IP address of the PC.
    • Run the winipcfg /release command in the MS-DOS of Windows 98 to release the IP address of the PC.

    The user PC needs to send a DHCP Release message to the DHCP server.

  • Renewing the IP address lease time or applying for a new IP address

    The same command is used to apply for a new IP address and renew the IP address in the same operating system. Before applying for a new IP address, the PC (DHCP client) must release the original IP address. IP address releasing is not required if you want to renew the IP address lease time.

    Different commands are used in different operating systems. You can use either of the following methods to apply for a new IP address:

    • Run the ipconfig /renew command on the Windows 7 operating system of the PC to apply for a new IP address.
    • Run the winipcfg /renew command in the MS-DOS of Windows 98 to apply for a new IP address.

    The user PC needs to send a DHCP Discover message to the DHCP server.

Translation
Download
Updated: 2019-03-21

Document ID: EDOC1000166635

Views: 130512

Downloads: 284

Average rating:
This Document Applies to these Products
Related Documents
Related Version
Share
Previous Next