Some of sysctl parameters are not available in the configuration after reboot.
Initial configuration:
```
set interfaces tunnel tun0 address '100.64.0.1/30'
set interfaces tunnel tun0 encapsulation 'gre-bridge'
set interfaces tunnel tun0 local-ip '203.0.113.1'
set interfaces tunnel tun0 mtu '1500'
set interfaces tunnel tun0 multicast 'enable'
set interfaces tunnel tun0 parameters ip ttl '64'
set interfaces tunnel tun0 remote-ip '203.0.113.2'
set system sysctl custom net.ipv4.conf.tun0.accept_local value '1'
```
Reboot instance:
```
vyos@r4-1.3# show system sysctl
custom net.ipv4.conf.tun0.accept_local {
}
[edit]
vyos@r4-1.3#
vyos@r4-1.3# load /config/config.boot
Loading configuration from '/config/config.boot'
Load complete. Use 'commit' to make changes effective.
[edit]
vyos@r4-1.3# compare
[edit system sysctl custom net.ipv4.conf.tun0.accept_local]
+value 1
[edit]
vyos@r4-1.3#
```