IPSec also does not support routing protocols, such as Enhanced Interior Gateway Routing Protocol (EIGRP) and Open Shortest Path First (OSPF), or non-IP traffic, such as Internetwork Packet Exchange (IPX) and AppleTalk.Hence the use of GRE. If you are not comfortable with GRE the only thing taht comes to my mind is CET which can replace GRE.
If you want to run OSPF over IPsec, you will need to do so over a GRE tunnel. The same goes for EIGRP, RIP and all other interior gateway protocols. However, you can run BGP through an IPsec tunnel with using a GRE tunnel. See the "Redundant Routes in IPsec VPNs" white paper on my web site for a discussion of the alternatives and examples of both OSPF over GRE over IPsec and BGP over IPsec with no GRE.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...