GLBP not working.

bsouza472 · ‎07-19-2010

Dears,

I have problems working with GLBP protocol in my network. I will try explain the scenario.

We have two data links from different ISP´s and each data link is in a router (ISP1 into 1811W and ISP2 into 1841).

I´m doing standard configurations about GLBP, but the internet traffic is instable, some services like citrix, Office Communicator and Exchange every times sign out and after few seconds sign in again.

Acctualy the principle of GLBP is working, when one link fails another get all traffic, but the services like Citrix, Exchange and Office Communicator (all servers not local. I´m in Brazil and the servers in U.S) not working well. I appreciate a lot if anyone can help me with this issue, and sorry about my english.

Bellow you can see configuration.

Thanks again.

Bruno Souza.

R1

interface fastethernet 0/1

ip address 192.168.1.2 255.255.255.0

glbp 10 ip 192.168.1.1
glbp 10 priority 250

glbp 10 preempt

glbp 10 load-balancing host-dependent

R2

interface fastethernet 0/1

ip address 192.168.1.3 255.255.255.0

glbp 10 ip 192.168.1.1
glbp 10 priority 200

glbp 10 preempt

glbp 10 load-balancing host-dependent

Reza Sharifi · ‎07-19-2010

Hi Bruno,

Are you using NAT?

Have a look at this document. You may need to change the load balacing method and test again.

HOST DEPENDENT

The MAC address of a host is used to determine which VF MAC address the host is directed towards. This ensures that a host will be guaranteed to use the same virtual MAC address as long as the number of VFs in the GLBP group is constant.

Host dependent load balancing will need to be used when using statefull Network Address Translation (NAT) because it requires each host to be returned the same virtual MAC address each time it sends an ARP request for the virtual IP address

http://cisco.biz/en/US/prod/collateral/iosswrel/ps6537/ps6554/ps6600/product_data_sheet0900aecd803a546c.html

HTH

Reza

bsouza472 · ‎07-20-2010

Hello Reza Sharifi, thanks for help.

I´m using NAT in the two routers and I have tried this three types of load balance methods. Now, this article shows more clear when is necessary to use host dependent in a load balance method.

Can I use another way that it isn´t NAT and alow hosts to have access on internet? If possible I can do a test using another load balance type, like weighted.

Thanks again.

Bruno Souza