While subscriber connects/disconnects to remote-access l2tp vpn every routing protocol daemon outputs error message like this:
Oct 06 13:29:20 bgpd[923]: [VCGF0-X62M1][EC 100663301] INTERFACE_STATE: Cannot find IF l2tp0 in VRF 79
Oct 06 13:29:20 ripd[930]: [VCGF0-X62M1][EC 100663301] INTERFACE_STATE: Cannot find IF l2tp0 in VRF 79
Oct 06 13:29:20 ripngd[933]: [VCGF0-X62M1][EC 100663301] INTERFACE_STATE: Cannot find IF l2tp0 in VRF 79
Oct 06 13:29:20 ospfd[936]: [VCGF0-X62M1][EC 100663301] INTERFACE_STATE: Cannot find IF l2tp0 in VRF 79
Oct 06 13:29:20 ospf6d[939]: [VCGF0-X62M1][EC 100663301] INTERFACE_STATE: Cannot find IF l2tp0 in VRF 79
Oct 06 13:29:20 ldpd[957]: [VCGF0-X62M1][EC 100663301] INTERFACE_STATE: Cannot find IF l2tp0 in VRF 79
Oct 06 13:29:20 eigrpd[961]: [VCGF0-X62M1][EC 100663301] INTERFACE_STATE: Cannot find IF l2tp0 in VRF 79
Oct 06 13:29:20 staticd[964]: [VCGF0-X62M1][EC 100663301] INTERFACE_STATE: Cannot find IF l2tp0 in VRF 79
Oct 06 13:29:20 bfdd[967]: [VCGF0-X62M1][EC 100663301] INTERFACE_STATE: Cannot find IF l2tp0 in VRF 79
Oct 06 13:29:20 isisd[200162]: [VCGF0-X62M1][EC 100663301] INTERFACE_STATE: Cannot find IF l2tp0 in VRF 79
Client has nothing to do with VRF 79, moreover - there is no VRF table 79 on the system. The number is random usually. It can be 0 or any.
The messages are very annoying and they have unjustifiably high level - error. On the system with several thousands of clients the log file grows to several Gb in less than an hour. We can't filter errors from routing protocols - as we would lost the BGP peering events then.