Is it possible to run multiple NTP server instances on the same system? We're using CentOS for our NTP system and want to synchronize specific time depending on what interface the client comes in on. Thanks.
You can not bind two processes (daemons) to the same socket (same IP/port). If you want to run two NTP instances, you can do this by binding each one to specific interface IP address.
As @Chris said, it is also useless to run two NTP daemons on the same host. The time is sent in UTC (GMT time).