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Questions tagged [mpls]

For questions about Multi-Protocol Label Switching (MPLS), the layer 2.5 protocol used as a transport layer for Traffic Engineering, some Layer 2 & 3 VPN's, and VPLS.

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VPLS without route target and VPLS ID

lately I have been checking out some old IOS-XE PEs in the environment that are peering with each other directly before route reflectors were introduced. they are using BGP autodiscovery and signaling....
daniel gor's user avatar
4 votes
1 answer
108 views

Why does `show rsvp neighbor` show every neighbour twice?

When I configure MPLS and RSVP on various Juniper devices, label-switched paths are successfully setup and seem to generally work, but the output of show rsvp neighbor always show each neighborship ...
miho's user avatar
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1 vote
0 answers
37 views

L2 Circuit ober BGP Signaled MPLS

We are providing MPLS Network services to Customers via Ethernet Links. Our CPEs (mainly Cisco) are linked via VLAN Subinterfaces to the PEs (Juniper MX). Due to the increasing demand of Multiple ...
Andreas Schaefer's user avatar
1 vote
0 answers
26 views

mpls load balancing in the core

Hi I am working with this topology: The BNG router receives from the 2 NCS5508 (P routers) l2vpn traffic that terminates in l3 on a PWHE interface. Those interfaces are used as subscriber interfaces ...
V Dp's user avatar
  • 21
0 votes
0 answers
74 views

MPLS labels for BGP prefixes

I've just started studying about MPLS and the labels it uses and this was mentioned in my study resource. When we use LDP on Cisco IOS, we locally generate a label for each prefix that we can find in ...
Mitrixsen's user avatar
  • 867
0 votes
2 answers
89 views

Do Forwarding Table (FIB not LFIB) have MPLS label?

In my opinion, FIB doesn't have MPLS label, FIB should be populate from RIB because of CEF. However, after I seach online and find out that some tutorial stated that FIB also contains the label just ...
jacky chong's user avatar
1 vote
1 answer
79 views

Recognizing the next protocol in MPLS header

How can I know what is the next protocol in MPLS header? I do know that MPLS header does not provide any information about the next protocol, But I somehow need to know how to recognize it, as I am ...
user89902's user avatar
0 votes
1 answer
885 views

QinQ does not work with L2VPN (VSI and MPLS L2VC - Switch Huawei)

Currently, I am trying to configure a network to transport multiple VLANs for a client who has points in different locations (Side A and Side B). My idea was to use QinQ for this. The network topology ...
Claudio Elzio's user avatar
1 vote
1 answer
66 views

In what situations is MPLS label erased from the top of the label stack in MPLS?

What are other processes that MPLS/IP routers can do with, or to MPLS label stack?
Vladimir Pejanovic's user avatar
0 votes
1 answer
18 views

How can GMPLS unify signalization plain of all telecommunications network technologies?

In what way can GMPLS do that unification of signalization of network technologies, by hardware, like MPLS switches, or by network protocols? And what is the role of optical networks in GMPLS? Are ...
Vladimir Pejanovic's user avatar
2 votes
1 answer
78 views

Why is MPLS label added between layer 2 header and layer 3 header of OSI model and not between headers of layer 3 and 4 of OSI model?

Is there a possibility to use any other two OSI model layers' middle positions? What is the basic concept of switching of packets with MPLS on layer 2.5 of OSI Reference model?
Vladimir Pejanovic's user avatar
1 vote
2 answers
114 views

Why does MPLS use labels to make forwarding decisions instead of destination IP addresses?

I am learning about MPLS at the moment. I know that routers in general make forwarding decisions based on the destination IP addresses and available routes in the routing table. However, with MPLS it'...
Mitrixsen's user avatar
  • 867
0 votes
1 answer
100 views

Layer 2 MPLS VPN versus Layer 3 MPLS VPN

A networking course that I follow briefly mentions Layer 2 and Layer 3 MPLS. I understand the difference between them. However, the question is, are L2/L3 MPLS like two different services that we can ...
Mitrixsen's user avatar
  • 867
5 votes
6 answers
1k views

Leased Lines vs MPLS

I am studying about WANs and there's been a mention of several WAN options/technologies. I know that Leased Lines are dedicated connections that are not shared by other customers while MPLS is a ...
Mitrixsen's user avatar
  • 867
1 vote
2 answers
189 views

Practically speaking, what is MPLS?

Theoretically speaking, Multi Protocol Label Switching is basically some sort of a routing technique that uses "labels" in contrast to normal routing using IP address. But what is it ...
user1783484's user avatar
0 votes
1 answer
35 views

why SR LSP no tunnel interface? but SR TE need it?

I'm a bit confused that why SR LSP(or LDP LSP) no need to config a tunnel interface, but SR TE(or MPLS TE) need it. how the tunnel interface works?
FLYFLY's user avatar
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3 votes
2 answers
268 views

what is meaning of MPLS when compared to SD-WAN? is it dedicated MPLS or MPLS VPNs

SD-WAN is always compared with MPLS, but it is not clear to me what is the meaning of MPLS in this context. My ambiguity is between these cases. MPLS VPN services provided and managed by operators ...
shahriar's user avatar
2 votes
0 answers
39 views

How lsp-ping works with php in picture?

If my understanding is correct, lsp-ping will have destination IP addresses set to loopback address(127.0.0.x), to force the label switching of the packet and thus checking the LSP connectivity. When ...
Hemanth's user avatar
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2 votes
1 answer
568 views

How is the destination MAC address filled during MPLS label switching?

During IP packet forwarding, after a LPM(ip lookup) done on the FIB, it will fetch the Nexthop ip address and the egress interface to send out the packet. Now, ARP table lookup is done for this ...
Hemanth's user avatar
  • 1,124
1 vote
0 answers
92 views

How do I set up IPv6 multicast over an MPLS carrier?

I'm setting up an MPLS carrier with VPNs in GNS3, using Cisco 7200 routers. Exact version I'm using is C7200-ADVIPSERVICESK9-M Version 15.2(4)S5, but I'm willing to upgrade/change if that's needed. On ...
Thomas's user avatar
  • 121
0 votes
1 answer
30 views

exchange routes and prefixes of remote clients in the mpls

is it possible to exchange routes and prefixes of remote clients in the mpls by an ospf? to avoid creating each time BGP sessions between PEs especially when the topology is scalable
Najeh Touil's user avatar
0 votes
3 answers
1k views

What is the difference between MPLS, MPLS VPN and IPsec VPN tunnel?

What is the difference between MPLS, MPLS VPN and IPsec VPN tunnel? I know that MPLS is a type of WAN. and IPsec VPN tunnel is an encrypted connection (private) over the internet. But what is MPLS VPN?...
Errefae's user avatar
2 votes
2 answers
1k views

Do Juniper l2circuit services (ccc) support a mismatched encapsulation type?

I am building an l2circuit ccc (draft-martini) between an EX4500 and an MX204. The issue is that I need to have mismatched l2circuit encapsulation-type on either side. The East-coast EX4550-32F (Junos:...
Mike Pennington's user avatar
1 vote
2 answers
128 views

What's the advantage of using SDWAN over MPLS/Circuit Lines?

I am trying to figure out. What's the advantage of using SDWAN over MPLS/Circuit Lines? Some Companies goal is to reduce costs so they migrate MPLS/Circuit Lines to SDWAN. Is there any engineering ...
Jim Pap's user avatar
  • 419
2 votes
1 answer
140 views

What are LDP-MPLS advantages?

An LDP-MPLS is deployed on a network and labels are used for packet forwarding. As you may know, LDP needs IGP and there is IGP too. Because there is no RSVP, there is no traffic engineering and there ...
A.A's user avatar
  • 551
0 votes
1 answer
118 views

Why do we need a Route Distinguisher in VPNv4 routes if there is already a VPN label?

I know the explanation about the usage of RD, that it makes routes from different VRFs globally unique. AFAIK, a VPN route is composed of [RD] + [VPN label] + [Prefix] Isn't the VPN label, that is ...
manish ma's user avatar
  • 1,644
1 vote
1 answer
493 views

MPLS LDP transport address should it be always loopback IP

Can the transport address for the LDP be different from the loopback IP? LSR ID would be loopback while the transport address would be interface IP. For example, if the interface IP is the transport ...
Goldy Tomy's user avatar
1 vote
2 answers
291 views

How to isolate in VRF clients with public IPs in MPLS ISP network

I have OSPF and MPLS enabled in network and run xconnects to transmit L2 traffic. But also have just Internet clients that want public IP addresses. So I configure public IP on interface towards ...
pad19's user avatar
  • 31
0 votes
2 answers
109 views

What are the benefits of using a transport label in L3VPN?

If not utilizing any form of TE (Traffic Engineering), are there any benefits of using a transport label in L3VPN - instead of just using a simple IPinIP tunnel? e.g. if traffic is egressing PE1 with ...
manish ma's user avatar
  • 1,644
0 votes
3 answers
204 views

How are MPLS routers connected to each other?

So MPLS is one of the many ways to connect two or more distant sites. In other words, it is some kind of a "WAN solution". But what is the "WAN solution" for MPLS? Take for example ...
Noob_Guy's user avatar
  • 491
1 vote
1 answer
97 views

Is this how ATM and SONET work?

This is how I visualize how SONET carry ATM, and how ATM carry IP: Is my visualization correct?
Noob_Guy's user avatar
  • 491
0 votes
1 answer
85 views

How does a Cisco router determine if a packet is IP routed or label switched?

How does a Cisco Router (IOS-XE) decide if a Packet will be MPLS Label switched or ip routed? In a Juniper MX MPLS Pathes have an own Administrative Distance (or Preference in Junipers wordings) So ...
Andreas Schaefer's user avatar
1 vote
0 answers
164 views

Getting VRF to work (and some other questions)

I'm messing with BGP/MPLS for the first time and I have some doubts both in if I'm doing something wrong with my configuration and if it is the best approach, hope you guys can clarify me a bit here. ...
DevM's user avatar
  • 101
3 votes
1 answer
740 views

Many ways of configuring MPLS pseudowires, and choosing only one

I am discovering MPLS configuration on Cisco ASR920, and for almost any "thing" that can be configured, there is often two or more ways to do it. For example, given this configuration: ...
mat's user avatar
  • 133
2 votes
1 answer
110 views

MPLS-BGP - VPN isolation - RFC 4364

In Section 6 of RFC-4364, it is stated that, if MPLS is being used as the tunneling technology (in the scope of forwarding VPN-IPV4 traffic from one PE to an other) , this means that a router in the ...
Segfault's user avatar
2 votes
1 answer
531 views

Transporting an Ethernet Port in a LDP Based VPLS Instance on Juniper MX routers

We are currently transporting an Ethernet Port using LDP Based Layer 2 VPN service (P2P PW) in Juniper MX.This P2P LDP PW is up and currently working. Below is the configuration against this:- set ...
Nabeel's user avatar
  • 1,130
3 votes
1 answer
742 views

MPLS xconnect L2VPN with tagged interface (subinterface) and untagged interface

We need to extend a specific device directly connected to the core network to an existing L2VPN with an MPLS xconnect L2VPN. But we encounter a problem. Indeed, one side recquire sub interface and ...
Eraseth's user avatar
  • 425
0 votes
0 answers
182 views

How to connect EVPN DC Fabric to MPLS IP VPN Backbone

Let's suppose that we have a common Clos EVPN/VXLAN-based DC fabric with IP gateways on leaves (anycast gateways). Also there is a lot of different IP VRFs inside a fabric where end hosts reside. What ...
Anton M.'s user avatar
  • 187
0 votes
1 answer
246 views

Interconnecting sites with different networks and VLANs

I've got three sites, let's call them Production Plant, Remote 1 and Remote 2. They're not big networks. The Production Plant has two internal networks that has control systems designed for all being ...
Vincent Vega's user avatar
0 votes
1 answer
1k views

What is the difference between Targeted LDP and Directed LDP in MPLS?

Please explain the main differences (use cases) between Targeted LDP and Directed LDP in MPLS ?
Andy's user avatar
  • 115
1 vote
2 answers
197 views

Do X.25/Frame Relay/ATM/MPLS have their own switches?

In the context of networking when we say "switch" we always think of Ethernet switch. But do we have X.25 switch, Frame Relay switch, ATM switch, and MPLS switch? If yes, how are they ...
Noob_Guy's user avatar
  • 491
1 vote
1 answer
213 views

How are labels in LDP "Label Mapping Message" associated with IP prefix?

Let's say, that I have two directly connected routers r1 and r2. For example, I do see that the r2 sends a Label Mapping Message to r1 and provides several labels including 21(0x15): r1 associates ...
Martin's user avatar
  • 1,109
0 votes
1 answer
294 views

Why does Junos create two entries in LIB for single tag- one with "S=0" and other with implicit "S=1"?

In the penultimate LSR there are following two entries for label 301040: root@r2> show route table mpls.0 protocol rsvp mpls.0: 14 destinations, 14 routes (14 active, 0 holddown, 0 hidden) + = ...
Martin's user avatar
  • 1,109
0 votes
1 answer
303 views

Why are the LDP installed LSPs not seen in the output of "show mpls lsp" in Junos?

I have established a LDP session between routers r1(lo0.0 has 192.168.1.1 configured) and r4(lo0.0 has 192.168.1.4 configured). According to show route table inet.3 192.168.1.4 in r1 the BGP prefixes ...
Martin's user avatar
  • 1,109
2 votes
1 answer
3k views

What's the difference between L2TP and L2TPv3? [closed]

Is L2TPv3 an improvement of L2TP or a completely different technology? Other than "it scales better" and "the non-proprietary MPLS" I can't find much information about it that's ...
Vita's user avatar
  • 195
0 votes
1 answer
169 views

How to compare two DSCP ? which one of DSCP 28 and 34 (decimal) has more priority?

How to compare two DSCP ? for example which one of DSCP 28 and 34 (decimal) has more priority ?
AMEL BENAIDA's user avatar
2 votes
1 answer
191 views

Brocade L2VPN Route Reflector

I am trying to create an MPLS VPLS network where the VPLS instances are auto-discovered via BGP L2VPN. The issue I'm currently facing is that the routes are not reflected and there seems to be no ...
metrotyranno's user avatar
1 vote
1 answer
2k views

Secure MPLS configuration: Does TCP port 646 (LDP) need to be generally exposed?

I am looking for expertise on MPLS configurations and security. A recent Nmap scan of my organization's public IPv4 perimeter networks has discovered a system which appears to be listening on TCP port ...
khantext's user avatar
1 vote
0 answers
69 views

Why is SD-WAN a more suitable option than MPLS for cloud? [closed]

I keep coming across the statement that because of the growth in cloud computing, SD-WAN is a more suitable option than MPLS for connecting remote sites. Can anyone give me an explanation why?
s h a a n's user avatar
  • 113
0 votes
2 answers
298 views

Pros and cons of using VPLS instead of using MPLS alone

What are the pros and cons of using VPLS instead of MPLS alone? What are the typical cases where VPLS is used?
Rumesh Madhusanka's user avatar