On Wed, 8 Jun 2022, BERTRAND Joël wrote:
Your script runs, but SEC is only a backup and I have to switch back to
PRI as soon as possible (PRI has a fixed IP address).
That's possible too. Just fill in the is_up_primary()--telnet: nc -t,
https: curl -S, snmp, whatever--to query the status of the primary
router's outbound connection and return true or false:
```
#!/bin/sh
PRI=192.168.15.19
SEC=192.168.15.20
R=$PRI
H=8.8.8.8
T=10
is_up_primary() {
# if curl -S http://$PRI/... | grep -q ...
# then true
# else false
# fi
return $((RANDOM % 2))
}
sw_route() {
local R=$1
route add default gw $R
echo switched to $R
}
while :
do if ! ping -nc1 $H >/dev/null 2>&1
then case $R in
$PRI) R=$SEC ;;
$SEC) R=$PRI ;;
esac
sw_route $R
S=1
else case $R in
$SEC) if is_up_primary
then R=$PRI
sw_route $R
fi
;;
esac
S=$T
fi
sleep $S
done
```
-RVP
