network – Ip routing table collection in realtime using passive and non-intrusive way

We want to.collecy IGP and BGP routing table for analysis and route changes.
Using ClI/SNMP it can be collected, but route table ia big and taking more.time, also let ad router.
Syslog/Trap enabling for route changes will not capture the entire entries..we.need.aging details also. May be peering can be useful to collect, but all the router in the network to be peered.

Please suggest a better and optimal way for this problem.

Thanks.