Skip to main content
10 votes
Accepted

What is the difference between L2TP vs GRE

L2tp and GRE are totally diffrent protocols 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 ...
Mr.lock's user avatar
  • 1,733
10 votes

Why PPTP, L2TP, PPPOE are in OSI Layer2?

PPTP, PPPoE, and L2TP all provide OSI Layer 2 services. That is, the user of these protocols (usually, a network layer protocol suite) thinks it's running over a "normal" link layer. ...
Jeff Learman's user avatar
9 votes

PPPoE vs L2TP protocols

The most and noticeable different is layer of tunneling. PPPOE is a Layer 2 (Data Link Layer) tunneling protocol while L2TP is a Layer 3 (Network Layer) tunneling protocol. This means that PPPOE can ...
SuB's user avatar
  • 308
5 votes

What's the difference between L2TP and L2TPv3?

Let's say that it is a 'new protocol heavily based on L2TPv2'. It shares a lot of the messages, constructs, flows with L2TPv2 but it is not strictly backwards compatible. It does have an L2TP '...
KillianDS's user avatar
  • 1,029
5 votes

Is L2TP really a Layer 2 protocol?

Fixed layer count models and tunneling don't match up very well. Our stack might look something like. Appliction data. TCP (inner network) IP (inner network) Ethernet framing (inner network) L2TPv3 ...
Peter Green's user avatar
  • 13.4k
4 votes
Accepted

How do protocols like PPTP, L2TP work below IP level

In real life, you can't stick to the OSI model entirely. It's helpful and necessary as a guide on how to structure the components in a complex network but you can't always say that's layer x. ...
Zac67's user avatar
  • 85.5k
3 votes
Accepted

Why is L2TP based on PPP and not PPPoE?

PPP is independent of the underlying transport, PPPoE requires to be run on Ethernet (or a like tunnel). But of course, you can also run L2TP with PPPoE (RFC 3817).
Zac67's user avatar
  • 85.5k
3 votes

Is L2TP really a Layer 2 protocol?

Tunneling protocols like L2TP, GRE, IPSEC and MPLS don't fit well into the OSI model. L2TP tunnels (encapsulates) L2 frames in UDP so it can be transported over layer 3.
Ron Trunk's user avatar
  • 67.7k
3 votes
Accepted

L2tp/IPSEC vs pure IPSEC

The same question was asked on the Information Security SE. Here's my answer to that question: L2TP/IPSec uses IPsec to protect the L2TP tunnel. So the real question is, why use L2TP? Layer ...
Ron Trunk's user avatar
  • 67.7k
2 votes
Accepted

Cisco ISR L2TP VPN local vs radius authentication problem

I found the problem. I did not think this would be it so I overlooked it multiple times but after trying it, it worked. I feel so silly now. On the virtual template 1 I changed ppp authentication ms-...
pieterk's user avatar
  • 181
2 votes
Accepted

How to configure L2TP Client on Juniper SRX?

As mentioned here, Juniper SRX cannot act as L2TP client.
Andrey Prokhorov's user avatar
2 votes

Cisco ASR1006 QoS on pppoe session: Police percent not supported - no bandwidth for percent calculation

What works for us (ASR 1001X) is the following concept (paraphrased config, syntax might be slightly different). The idea is to have a shaper in the parent class, so the child classes have a reference ...
Marc 'netztier' Luethi's user avatar
2 votes

How to centrally manage customer site's and users that have access to customer site's

Forget L2 VPN, it doesn't scale. Use routed/L3 VPN. Create a global addressing plan, so customer networks are all uniquely addressed. Allow space for future growth. If there's ambiguity, resolve it by ...
Zac67's user avatar
  • 85.5k
2 votes
Accepted

VyOS: Failure to commit after L2TPv3 configuration

K, it turned out that the version I was using is no longer supported! using the latest stable release I managed to achieve the L2TPv3 tunnel and pass traffic through it.
Hamdi Kadri's user avatar
1 vote
Accepted

Cisco ASA: virtual Pool IP not filtered via ACL

There are at least three ways I can think of to fix this issue, and I would attempt a solution in the following order: Craft your NAT statements differently (or remove the applicable NAT) so that the ...
user3629081's user avatar
  • 1,033
1 vote

Network Tunneling - why do we need it?

To put it simply, tunneling is the process of encapsulating data (think of it as putting inside a capsule) into another form of data so the network devices directly interact with the outside capsule......
itisMo's user avatar
  • 11
1 vote
Accepted

GRE over IPSec vs L2TP over IPSEC

So I have found the answer a year later while I was reading about IKEv1 vs IKEv2. L2TP/IPSec makes it possible to use a username/password, because L2TP is built on top of ppp. With GRE, that wouldn'...
pHeoz's user avatar
  • 590

Only top scored, non community-wiki answers of a minimum length are eligible