Configuring System Settings : About NTP authentication and servers
  
About NTP authentication and servers
NTP authentication verifies the identity of the NTP server sending time information to the SCC. RiOS 8.5 supports MD5-based Message-Digest Algorithm symmetric keys and Secure Hash Algorithm (SHA1) for NTP authentication. MD5 is a widely used cryptographic hash function that produces a 128-bit (16-byte) hash value. SHA1 is a set of related cryptographic hash functions. SHA1 is considered to be the successor to MD5.
NTP authentication is optional.
Configuring NTP authentication involves these steps that you can perform in any order:
Configure a key ID and a secret pair.
Configure the key type.
Configure the NTP server with the key ID.
The default NTP configuration points to the Riverbed-provided NTP server IP address 208.70.196.25 and these public NTP servers:
0.riverbed.pool.ntp.org
1.riverbed.pool.ntp.org
2.riverbed.pool.ntp.org
3.riverbed.pool.ntp.org
We recommend synchronizing appliances to an NTP server of your choice.