L2TP vs GRE

[satpot1981]

Hi all,

Can anyone clearly explain that what is the difference between L2TP and GRE tunnel?

I am  trying to understand where these protocol are used and why we use L2TP instead of GRE in some cases and vice versa.

Thanks

[smehrnia]

Hi Murat

GRE is a simple IP packet encapsulation protocol. a GRE tunnel is used when packets need to be sent from one network to another, without being parsed or treated like IP packets by any intervening routers. a GRE tunnel interface comes up as soon as it is configured and it stays up as long as there is a valid tunnel source address or interface which is up.

L2TP is a tunneling protocol (used to support VPNs) that allows multiplexing of multiple PPP sessions between two IP-connected endpoints, and a control protocol for dynamically establishing and maintaining the emulation of these PPP sessions. This is very different than GRE.

Hope it Helps,

Soroush.

[aain]

has anyone configured L2TP on cisco 9K nexus