mirror of
https://git.dn42.dev/wiki/wiki
synced 2025-03-13 03:06:33 +00:00
31 lines
1.0 KiB
Markdown
31 lines
1.0 KiB
Markdown
# GRE+IPsec
|
|
|
|
## Why GRE?
|
|
* [GRE](https://en.wikipedia.org/wiki/GRE) provides universal encapsulation on top of IP.
|
|
* It has a smaller header than UDP.
|
|
* GRE tunnels are processed in-kernel on *nix systems.
|
|
* It's supported by hardware routers.
|
|
|
|
## Why IPsec?
|
|
* GRE provides no encryption and authentication of it's own.
|
|
* IPsec in implemented in-kernel on FreeBSD and Linux with multithreaded encryption resulting in a lower latency than userspace VPN daemons using tun/tap interfaces.
|
|
|
|
## Problems with GRE
|
|
* GRE is defined directly on top of IP.
|
|
* Broken NAPT implementations will stop GRE tunnels.
|
|
|
|
## Problems with IPsec
|
|
* ESP is defined directly on top of IP.
|
|
* NAT support was added as an aftertought to IPsec.
|
|
* IKEv1 is too complex.
|
|
* Racoon has useless error messages.
|
|
|
|
## Requirements for sane operation
|
|
* Identify your peers by X.509 certificates
|
|
* At least one peer should operate his own (Sub-)CA.
|
|
|
|
## How to configure a GRE tunnel on FreeBSD
|
|
See [GRE on FreeBSD](gre-on-freebsd).
|
|
|
|
## How to configure IPsec on FreeBSD
|
|
See [IPsec on FreeBSD](ipsec-on-freebsd). |