Illustrated network: what is gateway load balancing protocol GLBP?

Hello , This is the network technology alliance station .

Two days ago, I introduced two first hop redundancy protocols ：

• Graphic network ： What is Virtual Router Redundancy Protocol  VRRP？

• Graphic network ： What is the hot backup router protocol HSRP？

Today we bring you the third first hop Redundancy Protocol ：

GLBP

.

Let's go straight to ！

Catalog

[TOC]

What is? GLBP？

• English full name ：
  Gateway Load Balancing Protocol

• Chinese name ：
  Gateway load balancing protocol

• Cisco  proper

• from  Cisco Systems  On  2005  Created in

• Provide redundancy 、 Load balancing

• GLBP  stay  UDP（ port  
  3222
  ） Work on , That is to say
  application layer

• GLBP  It's something like  HSRP  and  VRRP Of
  Virtual gateway protocol

• And  HSRP  or  VRRP  Different , It will not increase any management burden

GLBP advantage

• Route traffic to a single gateway , Share equally among multiple routers

• Load balancing
  ： Multiple devices can share information from  LAN  Client traffic , Thus, the traffic load is more evenly distributed among available devices .

• Provide automatic rerouting in case of any failure

• Multiple virtual devices
  ：GLBP  Support at most on each physical interface of the router  1024  A virtual router （GLBP  Group ）, Each group supports up to  4  Virtual Forwarders .

• Authentication
  ：GLBP Use MD5 Algorithm to improve reliability 、 Security and attempts to cheat  GLBP  Protocol software protection .

• Allow full use of resources on all devices , Without the administrative burden of creating multiple groups

GLBP role

GLBP There are two kinds of characters ：

AVG

• English full name ：
  Active Virtual Gateway

• Chinese name ：
  Active virtual gateway

act as  GLBP  Of the group  ARP  Responder , These responses are provided by  AVG  The distribution of  GLBP  Virtual of group members  MAC  Address composition .

AVF

• English full name ：
  Active Virtual Forwarder

• Chinese name ：
  Active virtual forwarder

GLBP  A member of the group , according to  Hello  Message understanding  AVG, from  AVG  Discover its virtual  MAC  Address .

GLBP Load balancing algorithm

GLBP There are three load balancing algorithms ：

Round-Robin

AVG  Assign serial to virtual  Mac  Address , For example, the first virtual  Mac  The address is assigned to  AVF1, Then assign to  AVF2  etc. .

GLBP  The default load balancing mode in , Applicable to any number of terminal hosts .

Host-dependent

If a specific host needs a specific virtual every time  Mac  Address , be  AVG  Will be specific  AVF  Assign to host .

A given host always uses the same router .

Weighted

Allocate virtual in proportion Mac Address , You can control the flow direction by changing the weight .

for example , If there are two routers in a group , also  R1  The forwarding capability of is router  B  Twice as many , Then router  A  The weight value of should be configured as  R2  Twice as many .

If it is Round-Robin Algorithm , Then the first virtual  Mac  The address is assigned to  AVF1, Then assign to  AVF2.

If you want virtual  Mac  The address is assigned to AF2, Can be achieved by modifying the weight , Pictured ,AF1 Of weight = 10,AF2 Of weight = 20,AF2 The weight of is greater than AF1.

GLBP state

GLBP Of AVG There are six states ,AVF There are four states ：

AVG Six states

• Disabled
  ： Indicates that virtual is not configured  IP  Address

• Initial
  ： Represent virtual IP Address configured , But the virtual gateway configuration is incomplete

• Listen
  ： Indicates that the virtual gateway is receiving  hello  Data packets , And be prepared to change to... When the active or standby virtual gateway is unavailable “Speak” state .

• Speak
  ： Indicates that the virtual gateway is trying to become  AVG

• Standby
  ： Ready to be the next  AVG

• Active
  ： Indicates that this gateway is  AVG, And it is responsible for responding to virtual  IP  Address of the ARP request

AVF Four kinds of state

• Disabled
  ： Indicates that no virtual is assigned  MAC  Address

• Initial
  ： Represent virtual  MAC  The address is normal , But the virtual forwarder configuration is incomplete

• Listen
  ： Virtual forwarder is receiving  hello  Data packets , If AVF Unavailable , Is ready to change to “Active” state .

• Active
  ： Indicates that the gateway is AVF, Be responsible for forwarding to the virtual forwarder MAC Address message

GLBP timer

GLBP There are three types of timers ：

Hold timer

Used to monitor the existence of group members .

The default hold timer is  10  second

.

Redirect timer

If it's due ,AVG  Faults will no longer be considered  AVF  Of   fictitious MAC Address , Even if there are still  AVF  Forward traffic to the virtual MAC Address .

The time interval of the redirection timer is  0  To  3600  Between seconds ,

The default value is  600  second

.

Secondary hold timer

If this timer expires , all  AVF  The virtual will be discarded MAC Address , And no one is responsible for it .

The scope is  600  To  64,800  second ,

The default is  14,400  second

（4  Hours ）.

HSRP、VRRP、GLBP Comparison between the three

Shared two days ago HSRP、VRRP And today GLBP Are the first redundant protocols , So what's the difference between the three of them ？

1、 meaning

• HSRP
  ：HSRP-Hot Standby Redundancy, Gateway load balancing protocol

• VRRP
  ：Gateway Load Balancing Protocol, Virtual router redundancy protocol

• GLBP
  ：Virtual Router Redundancy Protocol, Global load balancing Protocol

2、 Range

• HSRP
  ： Cisco proprietary

• VRRP
  ：IEEE standard

• GLBP
  ： Cisco proprietary

3、 standard

• HSRP
  ：RFC2281

• VRRP
  ：RFC3768

• GLBP
  ： nothing

4、OSI  layer

• HSRP
  ： The first 3 layer

• VRRP
  ： The first 3 layer

• GLBP
  ： The first 2 layer

5、 Whether load balancing is supported

• HSRP
  ： I won't support it

• VRRP
  ： I won't support it

• GLBP
  ： Support

6、 Multicast group  IP  Address

• HSRP
  ：HSRP  edition  1  Use multicast  IP  Address  
  224.0.0.2
  , edition  2  Use  
  224.0.0.102

• VRRP
  ：
  224.0.0.18

• GLBP
  ：
  224.0.0.102

7、 Transmission port number

• HSRP
  ：UDP 
  1985

• VRRP
  ：UDP 
  112

• GLBP
  ：UDP 
  3222

8、 Whether preemption is enabled by default

• HSRP
  ： Preemption is not enabled by default

• VRRP
  ： Preemption is enabled by default

• GLBP
  ： By default ,GLBP  Preemption is disabled , however , This function can be enabled manually

9、 The election

• HSRP
  ：

• Highest priority

• The highest  IP  Address

• VRRP
  ： I won't support it

• Highest priority

• The highest  IP

• GLBP
  ： Support

• Highest priority

• The highest  IP

10、IPv6  Support

• HSRP
  ： Support

• VRRP
  ： I won't support it

• GLBP
  ： Support

11、 authentication

• HSRP
  ： Support plain text and  MD5  authentication

• VRRP
  ： Support plain text and  MD5  authentication

• GLBP
  ： Support plain text and  MD5  authentication

12、 edition

• HSRP
  ： Support two versions  HSRP： edition  1  and  2, edition  1  By default  HSRP  edition

• VRRP
  ： Default  VRRP  Version is version  2, No version  1

• GLBP
  ： nothing

13、 fictitious  MAC  Address

• HSRP
  ： Be similar to
  0000.00 07.ac02
  , The last digit indicates the group number

• VRRP
  ： Be similar to
  0000.5e00.0102
  , The last digit indicates the group number

• GLBP
  ：
  0007.b4xx.xxxx

summary

GLBP  yes  Cisco  Proprietary agreement , Is the first hop Redundancy Protocol  (FHRP)  One of , And  HSRP  and  VRRP  Different , It allows traffic to be load balanced across multiple routers .

GLBP Specify a virtual router as AVG, Responsible for traffic forwarding and load balancing , The backup virtual router is called  AVF, Passive failover acting as a virtual gateway , If  AVG  Failure or inaccessibility , be  AVF  Will take over the virtual gateway role .

This article mainly introduces ：

• What is? GLBP？

• GLBP advantage

• GLBP role

• AVG

• AVF

• GLBP Load balancing algorithm

• Round-Robin

• Host-dependent

• Weighted

• GLBP state

• AVG Six states

• AVF Four kinds of state

• GLBP timer

• Hold timer

• Redirect timer

• Secondary hold timer

• HSRP、VRRP、GLBP Comparison between the three

• 1、 meaning

• 2、 Range

• 3、 standard

• 4、OSI  layer

• 5、 Whether load balancing is supported

• 6、 Multicast group  IP  Address

• 7、 Transmission port number

• 8、 Whether preemption is enabled by default

• 9、 The election

• 10、IPv6  Support

• 11、 authentication

• 12、 edition

• 13、 fictitious  MAC  Address

• summary

Thank you for reading , If you think the article will help you , Don't forget to like 、 Collection ！ Any questions , Welcome to discuss with me in the comment area below ！！！