This article describes how to change configuration on the switch in case of communication loss. To complete this task, two separate events must be configured:

• One to move the static gateway from 192.10.10.1 to 10.50.8.1 during the communication loss (name "Move_To_Main_ISP")
• One to revert the changes (name "Move_To_Second_ISP")

Please note that having both events active consecutively may consume excessive CPU, so only one should be enabled at the time.

1. The first step requires to set RPM as a mechanism to detect if pings to target IP "10.50.8.1" stop working. For this, a successive probe loss count of 5 was selected, using a ICMP traffic flow as the probe type:

   set services rpm probe MainLinkDown test Check1 probe-type icmp-ping
set services rpm probe MainLinkDown test Check1 target address 10.50.8.1
set services rpm probe MainLinkDown test Check1 probe-interval 5
set services rpm probe MainLinkDown test Check1 thresholds successive-loss 5

2. The second step is to indicate how the switch will react to the ICMP loss by matching attribute " ping_test_failed " with RPM " MainLinkDown " as the test owner. 

   set event-options policy Move_To_Second_ISP events  ping_test_failed
set event-options policy Move_To_Second_ISP within 30 trigger on
set event-options policy Move_To_Second_ISP within 30 trigger 2
set event-options policy Move_To_Second_ISP attributes-match ping_test_failed.test-owner matches MainLinkDown

   You then need to indicate the configuration changes needed in case the IP is no longer reachable. It also requires to disable this policy and its related RPM probe before enabling the second policy (which will monitor if connectivity with the target IP is reestablished):

   set event-options policy Move_To_Second_ISP then change-configuration commands "set routing-options static route 0.0.0.0/0 next-hop 192.10.10.1"
set event-options policy Move_To_Second_ISP then change-configuration commands "delete routing-options static route 0.0.0.0/0 next-hop 10.50.8.1"
set event-options policy Move_To_Second_ISP then change-configuration commands " deactivate event-options policy Move_To_Second_ISP "
set event-options policy Move_To_Second_ISP then change-configuration commands " deactivate services rpm probe MainLinkDown "
set event-options policy Move_To_Second_ISP then change-configuration commands "activate event-options policy Move_To_Main_ISP"
set event-options policy Move_To_Second_ISP then change-configuration commands "activate services rpm probe MainLinkUP"

3. The third step is to track once ICMP communication with 10.50.8.1 is working again. We increased the number of probes to 10 to ensure stability:

   set services rpm probe MainLinkUP test Check2 probe-type icmp-ping
set services rpm probe MainLinkUP test Check2 target address 10.50.8.1
set services rpm probe MainLinkUP test Check2 probe-count 10
set services rpm probe MainLinkUP test Check2 probe-interval 5

4. The last step is to indicate the actions taken by the switch once the target IP is reachable again by linking the new event policy with the second RPM using attribute " ping_test_completed ". The original policy will be reactivated and the second group disable.

   set event-options policy Move_To_Main_ISP events  ping_test_completed
set event-options policy Move_To_Main_ISP within 120 trigger until
set event-options policy Move_To_Main_ISP within 120 trigger 20
set event-options policy Move_To_Main_ISP attributes-match ping_test_completed.test-owner matches MainLinkUP

set event-options policy Move_To_Main_ISP then change-configuration commands "delete routing-options static route 0.0.0.0/0 next-hop 192.10.10.1"
set event-options policy Move_To_Main_ISP then change-configuration commands "set routing-options static route 0.0.0.0/0 next-hop 10.50.8.1"
set event-options policy Move_To_Main_ISP then change-configuration commands " deactivate event-options policy Move_To_Main_ISP "
set event-options policy Move_To_Main_ISP then change-configuration commands " deactivate services rpm probe MainLinkUP "
set event-options policy Move_To_Main_ISP then change-configuration commands "activate event-options policy Move_To_Second_ISP"
set event-options policy Move_To_Main_ISP then change-configuration commands "activate services rpm probe MainLinkDown"

   To avoid high CPU, the second policy and RPM probe must be disabled since the first commit. They will be automatically enabled only if the target IP is unreachable:

   deactivate event-options policy Move_To_Main_ISP
deactivate services rpm probe MainLinkUP

Full configuration: 

Results