I adapted the solution that I found (http://www.juniper.net/us/en/community/junos/script-automation/library/event/enable-primary-nexthop/) via script. In summary, a test icmp is configured for a particular IP and if no response the default route is changed.
Address:
FW Internal IP --> 10.1.1.1/24
FW External IP --> 200.1.1.1/24
Gateway primary --> 200.1.1.254
Gateway secontary --> 10.1.1.254
Following description of the solution:
- Copy the script (change_route-default.slax) to the folder /var/db/scripts/event
- set the ip to be monitored. RPM monitor
set services rpm probe internet-test test ping-google probe-type icmp-ping
set services rpm probe internet-test test ping-google target address 8.8.8.8
set services rpm probe internet-test test ping-google test-interval 5
set services rpm probe internet-test test ping-google source-address 200.1.1.1
set services rpm probe internet-test test ping-google thresholds successive-loss 6
set services rpm probe internet-test test ping-google traps test-failure
set services rpm probe internet-test test ping-google traps probe-failure
- Configure static route to the IP that will be monitored via the primary link.
set routing-options static route 8.8.8.8/32 next-hop 200.1.1.254
- Sets policy events.
# Policy to Link Primary
set event-options policy enable_link-primario events ping_test_completed
set event-options policy enable_link-primario within 30 trigger on
set event-options policy enable_link-primario within 30 trigger 1
set event-options policy enable_link-primario within 60 events ping_test_failed
set event-options policy enable_link-primario then event-script change_route-default.slax arguments next-hop 200.1.1.254
set event-options policy enable_link-primario then event-script change_route-default.slax output-filename foo
set event-options policy enable_link-primario then event-script change_route-default.slax destination foo
# Policy to Link Backup
set event-options policy enable_link-backup events ping_test_failed
set event-options policy enable_link-backup within 5 trigger on
set event-options policy enable_link-backup within 5 trigger 1
set event-options policy enable_link-backup within 20 events ping_test_completed
set event-options policy enable_link-backup then event-script change_route-default.slax arguments next-hop 10.1.1.254
set event-options policy enable_link-backup then event-script change_route-default.slax output-filename foo
set event-options policy enable_link-backup then event-script change_route-default.slax destination foo
set event-options destinations foo archive-sites /var/tmp
- Enable script.
set event-options event-script file change_route-default.slax
TROUBLESHOOTING
run show services rpm probe-results test ping-google owner internet-test
run show route
run op url /var/db/scripts/event/change_route-default.slax