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

NE20E-S2 V800R010C10SPC500 Feature Description - Network Reliability 01

This is NE20E-S2 V800R010C10SPC500 Feature Description - Network Reliability
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).
Basic VRRP Functions

Basic VRRP Functions

VRRP works in either master/backup mode or load balancing mode.

Master/Backup Mode

A VRRP backup group comprises a master router and one or more backup routers. As shown in Figure 5-9, Device A is the master router and forwards packets, and Device B and Device C are backup routers and monitor Device A's status. If Device A fails, Device B or Device C is elected as a new master router and takes over services from Device A.

Figure 5-9 Master/Backup mode
VRRP device configurations in master/backup mode are as follows:
  • Device A is the master. It supports delayed preemption and its VRRP priority is set to 120.
  • Device B is a backup. It supports immediate preemption and its VRRP priority is set to 110.
  • Device C is a backup. It supports immediate preemption and its VRRP priority is the default value 100.

VRRP in master/backup mode is implemented as follows:

  1. When Device A functions properly, user traffic travels along the path Device E -> Device A -> Device D. Device A periodically sends VRRP Advertisement packets to notify Device B and Device C of its status.

  2. If Device A fails, its VRRP functions are unavailable. Because Device B has a higher priority than Device C, Device B switches to the Master state and Device C remains in the Backup state. User traffic switches to the new path Device E -> Device B -> Device D.

  3. After Device A recovers, it enters the Backup state (its priority remains 120). After receiving a VRRP Advertisement packet from Device B, the current master, Device A finds that its priority is higher than that of Device B. Therefore, Device A preempts the Master state after the preemption delay elapses, and sends VRRP Advertisement packets and gratuitous ARP packets.

    After receiving a VRRP Advertisement packet from Device A, Device B finds that its priority is lower than that of Device A and changes from the Master state to the Backup state. User traffic then switches to the original path Device E -> Device A -> Device D.

Load Balancing Mode

VRRP backup groups work together to load-balance traffic. The implementation principles and packet negotiation mechanism of the load balancing mode are the same as those of the master/backup mode. The difference between the two modes is that in load balancing mode, two or more VRRP backup groups are established, and each VRRP backup group can contain a different master router. A VRRP device can join multiple VRRP backup groups and have a different priority in each group.

VRRP load balancing is classified into the following types:
  • Multi-gateway load balancing: Multiple VRRP backup groups with virtual IP addresses are created and specified as gateways for different users to implement load balancing.

    Figure 5-10 illustrates multi-gateway load balancing.

    Figure 5-10 Multi-gateway load balancing
    As shown in Figure 5-10, VRRP backup groups 1 and 2 are deployed on the network.
    • VRRP backup group 1: Device A is the master router, and Device B is the backup router.
    • VRRP backup group 2: Device B is the master router, and Device A is the backup router.

    VRRP backup groups 1 and 2 back up each other and serve as gateways for different users, therefore load-balancing service traffic.

  • Single-gateway load balancing: A load-balance redundancy group (LBRG) with a virtual IP address is created, and VRRP backup groups without virtual IP addresses are added to the LBRG. The LBRG is specified as a gateway to implement load balancing for all users.

    Single-gateway load balancing, an enhancement to multi-gateway load balancing, simplifies user-side configurations and facilitates network maintenance and management.

    Figure 5-11 shows single-gateway load balancing.

    Figure 5-11 Single-gateway load balancing
    As shown in Figure 5-11, VRRP backup groups 1 and 2 are deployed on the network.
    • VRRP backup group 1: an LBRG. Device A is the master router, and Device B is the backup router.
    • VRRP backup group 2: an LBRG member group. Device B is the master router, and Device A is the backup router.

    VRRP backup group 1 serves as a gateway for all users. After receiving an ARP request packet from a user, VRRP backup group 1 returns an ARP response packet and encapsulates its virtual MAC address or VRRP backup group 2's virtual MAC address in the response.

Translation
Download
Updated: 2019-01-02

Document ID: EDOC1100055473

Views: 11870

Downloads: 4

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