Cisco GLBP Load Balancing Options


Cisco Gateway Load Balancing Protocol (GLBP) is one of Cisco First Hop redundancy Protocols and it offers load balancing across multiple gateways. GLBP supports four types of load balancing options. How network hosts are assigned to each GLBP Router can be altered by using one of four load balancing options mentioned below. These options are not able to be deployed concurrently. There is a negligible CPU difference in the operation of either of these options.

There are four different types of Load balancing algorithms in GLBP:

1. None

2. Host dependent

3. Weighted

4. Round robin


If no load-balance algorithm is specified then GLBP will operate in an identical fashion to HSRP, the AVG will only respond to Address Resolution Protocol (ARP) requests with its own Virtual Forwarder (VF) MAC address, and all traffic will be directed to the AVG with no occurrence of load balancing.

Cisco-glbp_1(config-if)#glbp 1 load-balancing ?
host-dependent  Load balance equally, source MAC determines forwarder choice
round-robin     Load balance equally using each forwarder in turn
weighted        Load balance in proportion to forwarder weighting


  1. The Mac-address of the host is used to determine which AVF’s  mac is the host directed towards.
  2. A given host is guaranteed to use the same Virtual Mac as long as number of VF’s in the GLBP group are constant
  3. Host dependant GLBP is not recommended in situation where there are small number of hosts, for example, less than 20


  1. GLBP places a weight on each device to calculate the amount of load sharing that will occur through MAC assignment
  2. Each GLBP router in a group will advertise its weight and AVG will act based on that value
  3. For example  we have two routers, Router A and Router B. If router A has double the bandwidth capacity then router B. Router A will be configured with the double weighting value of router B


  1. With Round-robin VF mac-address is used sequentially in ARP replies for the virtual IP
  2. This is the default type of GLBP algorithm
  3. It is suitable for any number of hosts.






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  1. Sajith says:

    Hi Team

    I am doing my CCNP and I wd like to give this doc as ” FIVE STAR ” and its really cooool stuff on Load Balancing Options in Cisco GLBP.


  2. Sailesh says:

    Nice post about GLBP load balancing options in Cisco

  3. Anorkbere says:

    I understand load balancing options in Cisco GLBP, Thanks

  4. Wasim says:

    thanks! nice info on Cisco GLBP load balancing options

  5. Farid says:

    Nice one, You have covered all Cisco GLBP load balancing options…..

  6. Taran says:

    It completely explains all that’s available for GLBP nowadays. Great work. Keep it up.

  7. Carlee says:

    Thanks for being points on Cisco GLBP load balancing options…

  8. Vipin says:

    Thanks for sharing Cisco GLBP Load Balancing Options…

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