Questions tagged [l2tp]

L2TP (Layer Two Tunneling Protocol) extends the PPP model by allowing the L2 and PPP endpoints to reside on different devices interconnected by a packet-switched network. Use this tag for questions about L2TP

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36 views

Redundant physical interfaces for Cisco pseudowire-class

I have a link which is LT2P from a site router R1 (Cisco 867-VAE, IOS 15.3) which has two external interfaces defined (dialer1 and vlan-1000), but only one plugged in (first is ADSL, second is ...
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1answer
45 views

Juniper SRX Destination NAT for L2TP server

I have a L2TP server on my LAN which I would like to access from WAN and there is a Juniper SRX standing between these two networks. I've had some success with this post: https://forums.juniper.net/t5/...
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54 views

Cisco ASA L2TP remote-access VPN with addresses assigned by DHCP

I have an ASA with a working Cisco VPN Client configuration set up. I am trying to phase out the Cisco VPN Client, initially in favour of L2TP. The Cisco Client policy has end-users fetch their ...
2
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1answer
35 views

VyOS: Failure to commit after L2TPv3 configuration

I am trying to get familiar with VyOS (using a VM) and while working on L2TPv3 I encountered something strange: after configuring the L2TPv3 interface and try to commit, an error occurs as if the ...
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0answers
44 views

Cisco L2TP Tunnel and NAT

I have problems with NAT clients connected to an AP . This AP has an L2TP tunnel established to a Cisco router (7206VXR). The session is UP and the router can ping the IP of the client. The client ...
2
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1answer
193 views

How do protocols like PPTP, L2TP work below IP level

I have been using these protocols without deep understand how everything works under the hood. I understand a process of tunneling as follows When we are using protocols like OpenVPN, IPSec, SSH ...
1
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1answer
101 views

Cisco ASA: virtual Pool IP not filtered via ACL

One of our Customers has a corporate network at three different locations. Let's assume: location A: 192.168.1.0/24 location B: 192.168.2.0/24 and location C: 192.168.3.0/24 At each location a Cisco ...
5
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2answers
4k views

What is the difference between L2TP vs GRE

Can anyone clearly explain that what is the difference between L2TP and GRE tunnel? Is L2TPv3 Any different I am trying to understand where these protocol are used and why we use L2TP instead of ...
1
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1answer
351 views

Why is L2TP based on PPP and not PPPoE?

I'm trying to grasp why L2TP is based on PPP. I thought PPP was a protocol for point-to-point situations where you don't have Ethernet. So why/how is L2TP using PPP in order to establish communication ...
4
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3answers
2k views

Network Tunneling - why do we need it?

I have researched the topic of Network Tunnel but the information on this is rather confusing and inconsistent. So could someone please explain: In general, What is tunneling? Is it simply an act of ...
3
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1answer
478 views

GRE over IPSec vs L2TP over IPSEC

Every single VPN provider offers L2TP over IPSec. What is the reason GRE over IPSec is never offered ? Is there any downfall ? It seems to be exactly the same.
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1answer
1k views

How to configure L2TP Client on Juniper SRX?

I have an Juniper SRX 100, running JunOS 12.1X46-D66. I would like to use it to route all Internet traffic through an L2TP tunnel to an ISP called Andrews and Arnold, who offer this as a service. ...
5
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1answer
3k views

PPPoE vs L2TP protocols

I am trying to find differences between PPPoE and L2TP.Both are tunneling protocols. When to use what? thanks, GL
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0answers
68 views

What is wrong with my Fortigate LNS IP scheme configuration?

I'm trying to set up a VPN connection for a client-to-site scheme with a fortigate VM applicance. This is for testing puropose so all clients and the fortigate are runned on VMWare. Here is what I ...
3
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1answer
2k views

L2tp/IPSEC vs pure IPSEC

So, I was reading about the L2TP protocol and I understand what it basically does. But I fail to see why it would be preferred over pure IPSEC(VPN). VPN already provides end-to-end encryption between ...
4
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1answer
675 views

Cisco ISR L2TP VPN local vs radius authentication problem

I currently have a cisco 1841 router configured to authenticate users against a Windows NPS server. The strange thing is that when using local authentication the VPN connects first time every time. I ...
0
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2answers
678 views

Is L2TP really a Layer 2 protocol?

My naive understanding of how the internet works is as follow : Physical layer (1) Link layer (2) - Inside frames IP layer (3) - Inside IPv4 or IPv6 packets Transport layer (4) - Inside TCP or UDP ...
2
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2answers
512 views

Vyatta/EdgeOS remote access VPN without NAT?

I currently have a ubiquiti edgerouter setup with an ipsec site-to-site vpn and l2tp/ipsec remote access vpn. Both work as intended. Is it possible to configure the remote access (l2tp/ipsec) vpn to ...
2
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2answers
486 views

Cisco PPPoE over FA with L2TP client only (no IPSec)

This started as a question, with my connection failing to come up, but after a bit of trial and error, the configuration is working, so I've edited it into a solution. Access lists and address ...
3
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0answers
848 views

GRE tunnel(or even any tunnelling technique) between Alcatel 7750 and a Cisco Router

has anyone on here been able to successfully create a GRE tunnel or any kinda of tunnelling mechanism between an Alcatel router and a Cisco router. I've been struggling with this and for a while and ...
2
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2answers
9k views

Why PPTP, L2TP, PPPOE are in OSI Layer2?

PPTP, L2TP, PPPOE - these are tunneling protocols. And they are Data link Layer protocols. Why? As I understood, Layer2 protocols work only in same subnet. They don't use IP addresses and cannot be ...
3
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2answers
780 views

How does an L2TP Client know where to forward frame?

I'm currently studying about L2TP and there's something I don't quite understand, even after studying a tutorial and some parts of the RFC. Specifically, when connected via L2TP, how does the client ...
4
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2answers
671 views

problem with cisco asa 5505 vpn configuration

I have a problem with cisco asa 5505 vpn configuration. I set l2tp for windows clients. I can connect to vpn but: when i have "use default gateway on remote network" on NIC enabled i have access to ...
3
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1answer
6k views

L2TP over IPSEC with a LAN to LAN link

I'm looking to add security on a LAN to LAN link that we have in my network. This LAN to LAN link is used to extend vlans over 2 sites (local & remote). For now, the diagram is this one : I ...
5
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1answer
759 views

What happens when you stop receiving BPDUs with no L1 loss?

We have a redundant path for some of our communications through a.) a Metro-E provider and b.) two routers forming an L2TPV3 tunnel. We have Cisco 2960 switches at both ends running RSTP to prevent ...
9
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1answer
2k views

Strange drop-outs in Cisco 7200 LNS lab

I'm testing several functions on emulated Cisco 7200 routers, in GNS3, prior to actual purchase. One of the functions I've been testing out is LNS functionality. I've been primarily following this ...