Forum Discussion

Jim_Araujo_1061's avatar
Jim_Araujo_1061
Icon for Nimbostratus rankNimbostratus
Feb 26, 2015
Solved

Standalone GTMs in different DMZ with Different ISPs

Is there a way for the GTMs to detect a unplink is down based simply on ICMP ping?. The scenario I am trying to solve is we have two GTMs in standalone mode. Both are have Listener's in different DMZ...
application delivery
availability
BIG-IP DNS
design
dns
gtm
  • TJ_Vreugdenhil_'s avatar
    TJ_Vreugdenhil_
    Feb 26, 2015

    I have ran into the exact same scenario. I'm trying to recall what I did to fix it.

    A few things: 

    1) Don't use the bigip_link monitor(I believe that is specifically for link controllers), use the gateway_icmp or if doesn't give you the option in the WebUI, add it via the CLI.  Or create a new custom monitor. (may have to configure it as a transparent). 

2) Instead of using 8.8.8.8 use the next hop HSRP address (or one more hop above that) of your provider as the uplink address, and make sure you can traceroute and reach the address from the GTM. 

3) I believe there was also an issue in 11.5.1 that may be resolved with the latest hotfix for this.

    Let us know.

    Thanks! TJ

TJ_Vreugdenhil_'s avatar
TJ_Vreugdenhil_
Icon for Altostratus rankAltostratus

I have ran into the exact same scenario. I'm trying to recall what I did to fix it.

A few things: 

1) Don't use the bigip_link monitor(I believe that is specifically for link controllers), use the gateway_icmp or if doesn't give you the option in the WebUI, add it via the CLI.  Or create a new custom monitor. (may have to configure it as a transparent). 

2) Instead of using 8.8.8.8 use the next hop HSRP address (or one more hop above that) of your provider as the uplink address, and make sure you can traceroute and reach the address from the GTM. 

3) I believe there was also an issue in 11.5.1 that may be resolved with the latest hotfix for this.

Let us know.

Thanks! TJ

Jim_Araujo_1061's avatar
Jim_Araujo_1061
Icon for Nimbostratus rankNimbostratus
Feb 27, 2015
Ah, making a Custom monitor was the missing piece. Under Monitors --> choose ICMP type --> Transparent = Yes --> Alias address = what address you want to pin. Next add it to the Link object, router should be filled with the next hop router the gtm will use to reach the device you specified on the monitor. Thanks all!