Solved: GLBP help, MHSRP can complete the requirement

andyskyview · ‎12-17-2007

i would like to use the GLBP to do the load balance with my network. but the out come was not my expected when the wan link downed

i can use the MHSRP and two eigrp to complete the requirement. but the GLBP can not do it

requirement

1. the standby router will take all traffic when the active router its s0/0/0 interface down

2. The standby router will take all traffic when the active router opposite router ethernet down

Testing procedure

when i shutdown the s0/0/0 in the active router, the other forwarder can not take the active router traffic. the tracert from site B to site A diagram site_B_pc2_tracert1.jpg shown the destination host unreachable.

My design use two EIGRP to check the opposite ethernet network

attached show glbp, tracert files from site B to Site A

Please help me if you can

Edison Ortiz · ‎12-19-2007

I verified your configs. Please make the following changes.

SiteA Router1, remove:

glbp 10 priority 100

SiteA Router2, remove:

glbp 10 priority 95

Do the same on SiteB routers.

Unlike HSRP, priority does not decrement in GLBP, you decrement the weight.

I tested your config in a lab

________________________________

192.168.101.0/24 represents an external network on this sample:

From a device behind the GLBP

trace 192.168.101.1

Type escape sequence to abort.

Tracing the route to 192.168.101.1

1 192.168.2.102 0 msec 0 msec 0 msec

2 10.0.0.1 26 msec * 25 msec

Right now, R2 is handling the forwarding for this device.

If I go to R2 and shut down the serial interface.

sh track

Track 1

Response Time Reporter 1 reachability

Reachability is Down

10 changes, last change 00:00:20

Latest operation return code: Timeout

Tracked by:

GLBP FastEthernet0/0 10

The trace goes to R1:

trace 192.168.101.1

Type escape sequence to abort.

Tracing the route to 192.168.101.1

1 192.168.2.101 9 msec 0 msec 0 msec

2 10.0.0.1 33 msec * 26 msec

View solution in original post

Edison Ortiz · ‎12-19-2007

I verified your configs. Please make the following changes.

SiteA Router1, remove:

glbp 10 priority 100

SiteA Router2, remove:

glbp 10 priority 95

Do the same on SiteB routers.

Unlike HSRP, priority does not decrement in GLBP, you decrement the weight.

I tested your config in a lab

________________________________

192.168.101.0/24 represents an external network on this sample:

From a device behind the GLBP

trace 192.168.101.1

Type escape sequence to abort.

Tracing the route to 192.168.101.1

1 192.168.2.102 0 msec 0 msec 0 msec

2 10.0.0.1 26 msec * 25 msec

Right now, R2 is handling the forwarding for this device.

If I go to R2 and shut down the serial interface.

sh track

Track 1

Response Time Reporter 1 reachability

Reachability is Down

10 changes, last change 00:00:20

Latest operation return code: Timeout

Tracked by:

GLBP FastEthernet0/0 10

The trace goes to R1:

trace 192.168.101.1

Type escape sequence to abort.

Tracing the route to 192.168.101.1

1 192.168.2.101 9 msec 0 msec 0 msec

2 10.0.0.1 33 msec * 26 msec

andyskyview · ‎12-19-2007

Dear EdisonOrtiz

Thanks for your reply, as i know that the priority value is to determine the AVG on this group routers, do you agree ? i did the tested but the result still get the same problem when the tracked object down. fortunately, i found the other command on the

cisco and modified my config as below

glbp 10 weighting 110 lower 95 upper 105

glbp 10 weighting track 1 decrement 20

glbp 10 weighting track 2 decrement 20

i tested it ok

As i guess the problem is the weight value is not define the lower value, could you comments it?

BTW, could you tell me how to test the load balance, the tracert show alway use the same path to the destination , i need to clear the ARP in order to get the next path.

i tested the load balance option Weighted, Host dependant, Round robin, but i did not obvious the different and the effect. how to test it and monitor for each option

Thanks Again

Andy

Edison Ortiz · ‎12-19-2007

> as i know that the priority value is to determine the AVG on this group routers, do you agree ?

Yes

> As i guess the problem is the weight value is not define the lower value, could you comments it?

Funny, you mentioned that - I had that in my config (while playing around) but it wasn't in your config.

glbp 10 weighting 100 lower 95

By default, the lower weight is 1. That definitely helps on the failover.

> how to test it and monitor for each option

You need multiple devices and perform a traceroute to a destination via the GLBP

http://www.cisco.com/en/US/docs/ios/ipapp/command/reference/iap_d1.html#wp1013391