Ubuntu MikroTik GRE why does the tunnel crash when inactive?

Question

linux

It's written on Ubuntu

auto tun0
iface tun0 inet static
       address 10.10.0.1
       netmask 255.255.255.0
       up ifconfig tun0 multicast
     pre-up iptunnel add tun0 mode gre local ХХХ.ХХХ.ХХХ.ХХХ remote YYY.YYY.YYY.YYY ttl 225
       pointopoint 10.10.0.2
       post-down iptunnel del tun0

If you ping 10.10.0.2 from UBUNTU (GRE Mikrotik address) - the tunnel lives and everything works.
One has only to stop chasing packets through the tunnel, after N minutes it falls. (unreachable)
I start ping from UBUNTU to 10.10.0.2 - ping went... The tunnel went up.
And so in a circle.

At the same time, for some reason, the tunnel does not raise a ping from Mikrotik towards UBUNTU.

First time I see this.
Please tell me how to solve. To keep the tunnel up while UBUNTU and Mikrotik are online.
Thank you.

Answer 1

Hm. I encountered such moronic behavior when I worked with racoon. For this, I had to add a “service” in nagios that constantly kicked the nodes, and it was exactly as described - the tunnel rose only when pinged from one side :D
Maybe some timeouts or analogues of IPSec dead peer detection?

Answer 2

Uh-huh, I confirm the words of CityCat4 about the racoon. I then charged cron to do 1 ping every minute