Hello,
wrote: When i set vrrp authentication-key with md5, should the secret data be identical on both routers ?
No. Reading the source code of Juniper $9$ encryption algo shows that encrypted password starts with $9${salt}{random number} so the crypto result is different when performed in different places.
The source code of Juniper $9$ encryption algorithm is freely available on the internet
Java https://forums.juniper.net/t5/Junos/Password-encryption-algorithm-in-Junos/td-p/96208
Perl https://metacpan.org/pod/distribution/Crypt-Juniper/lib/Crypt/Juniper.pm
HTH
Thx
Alex