Mikrotik 7 Failover Script with ARP-PING and Source IP

Internet failover is essential to business health and resiliency. Failover prevents internet downtime that can cripple business operations.  Automatic failover techniques automatically redirects internet/data in the event of a network failure, thus keeping end-users connected and working.

Mikrotik ROS v7 brings many changes including the scripting updates, breaking older scripting functionalities. Following is customized script for ISP connectivity test, which performs following functions,

• Ping remote destination IP (intenret host or ISP Gateway) using ARP , Source IP & Interface,
  (This is useful when ISP have provided you P2P IP on your mikrotik, & this result no internet on mikrotik itself, so we can use ISP provided public ip as source NAT to faciliate ping results)
• Add timestamp into global variable,
• If PING fails to remote destination, perform required actions like change route destination or whatever you like,, or send email
• Set different variables
• After failure, if ping response comes OK , then perform actions like reverting the routes, or send email

Script: Tested with ROS 7.15.x

(I have scheduled it to run every 10 seconds, & based on threshold count, it will perform action)

# Mikrotik Failover Script for ROS 7.x
# This script is also useful if your ISP has given you P2P IP, so Mikrotik itself cannot ping any internet destination
# 1 July 2024
# aacable.wordpress.com / aacable AT Hotmail DOT com
# Define different Variables
:global ISP1LastChkTime ([ / system clock get date ] . " " . [ / system clock get time ]);
:global ISP1name
:global ISP1Health
:set ISP1name WAN1-MYISP
:local ISP1name WAN1-MYISP
# ISP-1 Interface 
:local ISP1INT WAN1
# ISP-1 Default Gateway
:local ISP1GW 103.163.254.93
# ISP-1 NATTED IP, (IP that ISP have provided for natted traffic, since we have p2p ip on Mikrotik therefore we have to use NATTED ip in order 
# to facilitate Mikrotik ping for internet
:local ISP1NatIp 103.163.254.94
# IP which Mikrotik will test for internet connectivity status, you can set it to any
:local ISP1PingTarget 8.8.8.8
:local ISP1PingCount 2
#:log warning "TESTING $ISP1GW via $ISP1INT GW $ISP1GW using $ISP1NatIp Mask IP ..."
# Please fill how many ping failures are allowed before fail-over happens
:local ISP1FailTreshold 2
# Define the distance increase of a route when it fails
:local ISP1DistanceIncrease 2
# -------------- stop editing here --------------
# Declare the global variables
:global PingFailCountISP1
# This initializes the PingFailCount variables, in case this is the 1st time the script has ran
:if ([:typeof $PingFailCountISP1] = "nothing") do={:set PingFailCountISP1 0}
# This variable will be used to keep results of individual ping attempts
:local ISP1PingResult
# Check ISP1
:set ISP1PingResult [ping $ISP1GW arp-ping=yes count=$ISP1PingCount interface=$ISP1INT]
:put $ISP1PingResult
#:log warning $ISP1PingResult
# If ping fails , result will be 0, so proceed with fail action
:if ($ISP1PingResult = 0) do={
:if ($PingFailCountISP1 < ($ISP1FailTreshold+2)) do={
:set PingFailCountISP1 ($PingFailCountISP1 + 1)
:if ($PingFailCountISP1 = $ISP1FailTreshold) do={
:log error "$ISP1name has a problem en route to $ISP1PingTarget - Performing Required Actions ..."
:log warning "Disabling $ISP1name INTERFACE $ISP1INT ... 10 SECONDS DELAY"
/ip route dis [find comment="WAN1_USERS_ROUTING_VIA_WAN1"]
/ip route set distance=10 [find comment="WAN1"]
/interface/disable [find comment="$ISP1name"]
:delay 3
:log warning "Enabling $ISP1name INTERFACE $ISP1INT ..."
/interface/enable [find comment="$ISP1name"]
:log warning "Done."
}
}
}
:if ($ISP1PingResult = 2) do={
:if ($PingFailCountISP1 > 0) do={
:set PingFailCountISP1 ($PingFailCountISP1 - 1)
:if ($PingFailCountISP1 = ($ISP1FailTreshold -1)) do={
:log warning "$ISP1name can reach $ISP1PingTarget again - Performing Required Actions ..."
/ip route ena [find comment="WAN1_USERS_ROUTING_VIA_WAN1"]
/ip route set distance=1 [find comment="WAN1"]
:log warning "Done."
}
}
}
:if ($PingFailCountISP1 = 0) do={
:set $ISP1Health UP
} else={
:set $ISP1Health DOWN
}

When Al OK (Below SS)

When ISP failure occurs… (below SS)

Logs when ISP failure occurs (Below SS)

Logs when ISP recovers (Below SS)

• Older Scripts for Reference purposes…

Mikrotik WAN monitoring script with multiple host check

Regard’s

Syed Jahanzaib