How to change the default route if the link to the gateway has fallen?

Question

Computer networks

Hello, the scheme is given:

If a link falls between R1 and ISP1, then I want R1 to change the gateway to the 0.0.0.0/0 grid from ISP1 to R2. How to do it on routeros or cisco ios?

Answer 1

wiki.mikrotik.com/wiki/Load_Balancing

Answer 2

For Cisco IOS there is an interesting thing called Embedded_Event_Manager . As far as I know, this thing works in conjunction with ip sla and applies one or another set of rules on an event.
Approximately, the following should turn out in the conf:
Describe and enable ip sla:

track 1 ip sla 1 reachability
 delay down 5 up 5

ip sla responder
ip sla 1
 icmp-echo <IP-dest-ISP1> source-ip <IP-Source-R1>
 frequency 5
ip sla schedule 1 life forever start-time now

Then we describe the events:

event manager applet ISP1_DOWN
 event track 1 state down
 action 2.0 cli command "enable"
 action 2.1 cli command "configure term"
 action 2.2 cli command "ip route 0.0.0.0 0.0.0.0 <IP-R2 or Interface-to-R2>"
event manager applet ISP1_UP
 event track 1 state up
 action 2.0 cli command "enable"
 action 2.1 cli command "configure term"
 action 2.2 cli command "no ip route 0.0.0.0 0.0.0.0 <IP-R2 or Interface-to-R2>"

I could be wrong, but in general it looks something like this