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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18
votes
1answer
1k views

MPLS auto-bandwidth balancing

I operate an MPLS/IP network that utilizes auto-bandwidth to measure bandwidth utilization and signal RSVP accordingly. How can I maintain balance across my LSP paths such that one large [P router]-to-...
17
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4answers
8k views

Are there any reasons to not use BFD?

In looking to implement Bidirectional Forwarding Detection (BFD) it seems to be very flexible in terms of timer tuning, light weight regarding any overhead and it's flexibility in terms of overall ...
15
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3answers
22k views

MPLS vs Encrypted VPNs - traffic security?

Why do people say a lot of times that they have two connections between two offices - the main one being over MPLS and the backup one over VPN. Why not run a VPN over MPLS too? Is MPLS secure? Can no ...
14
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3answers
5k views

BGP signalled MPLS issues

I am having an issue getting a VPLS up using an ME3600x with 15.3(2) and BGP signalling. @yelfathi and @packettalk have pointed me down the correct route but not sure how to resolve it. I have 2 ...
13
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2answers
2k views

VPLS Multihoming on Junos - FEC confusion‏

I'm going over the VPLS multihoming options on Juniper's web site. I'm not concerned with LAG and MC-LAG for the moment. As far as I'm aware: FEC128 is when you are using manual discovery of ...
11
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2answers
2k views

Handling VLAN based MPLS circuits with site specific internet access

I'm having difficulty wrapping my head around how to set this up and the MPLS vendor is being no help so I figured I would ask here. I have a 2 node MPLS each site having internet access on the same ...
10
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2answers
2k views

Why does my Cisco 6509 BGP table use two entries in my TCAM?

I have a problem on my Cisco 6509, each entry in my BGP table occupies two entries in the TCAM. If I show capacity forwarding, I see MPLS entries in L3 forwarding resources. But, I do not use MPLS on ...
9
votes
3answers
452 views

Cisco 2901 - Determine if bundled T1s are up based on bandwidth?

I have a Cisco 2901 at a remote branch office connected via ge0/1 to an Adtran that is managed by TW Telecom with 8 T1s bundled together for an MPLS circuit. I don't have access to the Adtran gear, ...
9
votes
1answer
1k views

Label Distribution Protocol(LDP) in MPLS

I have been going through the MPLS technology recently.I have this doubt in my mind after reading some of the features of the MPLS. A---B---c | | D----E Lets say routers A,E are LER and B,...
9
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2answers
2k views

Does Juniper set a control word on VPLS pseudowires

At the RIPE conference the was a talk about how MAC addresses starting with a 4or 6 may suffer from decreased performance because MPLS routers misinterpret the Ethernet packets as an IPv4/6 packet ...
9
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2answers
919 views

Label to Route mapping, Label generation scalability

In MPLS enabled routers, is a unique label generated per Destination prefix in routing Table or is it per Next-hop in the routing table if not both, how is the mapping between unique labels and ...
9
votes
1answer
2k views

Prefixes with aggregate labels not fully tracerouting across MPLS core

I have two routers, A (Cat6500 w/SUP720-3BXL, IOS 12.2(33)SXH4) and B (Nexus 7K w/SUP1, NX-OS 5.2(4)), separated by several hops across an MPLS core, each with VRF ABC. Router A has two directly ...
9
votes
1answer
638 views

EoMPLS, MSTP, and RPVST

We are looking at Cisco ME3600 to provide connectivity between our datacenter fabrics for some software defined networking. Due to the platform having a higher limitation on EoMPLS xconnects than ...
8
votes
3answers
15k views

What is the difference between VPLS vs Layer 2 VPN?

Apologies about the very open ended question, but I am struggling to differentiate between VPLS & L2 VPN's. I'm aware they both run over MPLS, but I can't find any documentation or sites that ...
8
votes
1answer
2k views

Cannot Load Internal Website over MPLS

We have an MPLS set up between two subnets. Everything (that is, I have RDP both directions as well as file-sharing) seems to be working correctly except for two things, which may be related. ...
8
votes
1answer
6k views

How to force VPLS/L2VPN to use a specific path

We're using VPLS and L2VPN on Juniper MX for L2 connections. Signaling is done via BGP and label distribution via LDP. Now we want one L2VPN to use a specific path trough the network and not follow ...
8
votes
2answers
1k views

How are the LERs determined in an MPLS LSP using LDP

Preface; In the below topology R1 and R6 are PEs, all others are P routers, all routers are running c7200-jk9s-mz.124-13b.bin. At this point IGP is fully converged (OSPF with all interfaces in area 0 ...
8
votes
4answers
4k views

How to signal a VPLS multihoming change to a L2 CE device

We have the following setup: Two MX routers connect to the same L2 site. Loop protection / redundancy is done via VPLS multihoming. On the other end are two switches (EX4200 for example). When the ...
7
votes
3answers
2k views

Alternatives to multiple Service Providers

I have one SP right now that serves 100 Sites and we are currently planning to migrate all the sites to a new SP. However, this will be a phased migration, so we will have some sites in the new SP ...
7
votes
2answers
4k views

Why are my equal cost LSP's not load balancing equally when using auto-bandwidth?

First, I'm adding this question and answering myself because this type of behavior was absolutely no where to be found, hopefully it will help someone. Problem: We use auto bandwidth to handle the ...
7
votes
2answers
742 views

Is there a way to create static LSP on a Brocade device?

Is there a way to create a static LSP (i.e. manually specifying in and out labels/interfaces, without LDP or RSVP) on a recent Brocade device running Netiron ? All I can find is an old Foundry static ...
7
votes
1answer
1k views

Configuring a second MPLS connection for our backup Data center (BGP Closed User Group)

I'm a bit new to BGP and need a little assistance with a configuration change. We are currently using our MPLS connection for all traffic to all sites. Going forward We would want to segragate the ...
6
votes
2answers
606 views

MPLS can reroute, but can it route?

I have 4 Cisco routers, connected one to another like the following: **R1**(s1/0)--(s1/0)**R2**(s1/1)--(s1/0)**R3**(s1/1)--(s1/0)**R4** All of them have an IP address assigned on their interfaces. ...
6
votes
2answers
633 views

Extending MPLS in to vSwitches

When your core network is MPLS based, how do you connect virtual servers behind vSwitches in to this? For example VMWare vDS or Cisco Nexus 1000v.
6
votes
1answer
3k views

Is it possible to run an IPv6 only MPLS core?

I am looking for information on whether it is actually possible to run an IPv6 only MPLS Core with respect to the transport labels, without the current requirement to tunnel across IPv4. To put this ...
6
votes
1answer
4k views

What is a FEC in MPLS domain?

Does FEC correspond to a Next-hop ipaddress or Destination Ipaddress or a combination of Next-hop/Destination Ipaddress and QOS values ?
6
votes
3answers
500 views

MPLS traffic engineering

While studying MPLS I couldn't understand it's one basic functionality. Mpls creates tunnel interfaces or pseudowires between label edge routers. To achieve traffic engineering I can set different ...
6
votes
3answers
33k views

Differences between MPLS and VPLS

Can someone explain to me what differences there are between MPLS and VPLS? Which one is the most efficient? Why? I’ve read that the only difference is layer of technology: 2 (VPLS) vs 3 (MPLS). Does ...
6
votes
2answers
2k views

In MPLS VPN, Which one become first? MPLS Label tag or VPN encapsulation?

In MPLS VPN network, which one is the first thing to do? I mean label tagging is first or VPN encapsulation is first? If you can, please explain about this case.
6
votes
1answer
1k views

Is it possible to stitch a L2VPN connection into a VPLS domain on Juniper MX

I'm trying to connect one end of a L2VPN tunnel to a VPLS instance on a Juniper MX router. The L2VPN should act like a local interface in the VPLS instance. Is this possible at all? I can't find any ...
6
votes
5answers
3k views

How to check MPLS connections?

I monitor about 150 routers with MPLS links. To check if connection is established, I'm pinging loopbacks visible only from WAN. If a loopback is not responding, I can see which link is not working ...
6
votes
1answer
2k views

Terminating an L2VPN on JunOS router

I am trying to terminate an L2VPN on an MX480 but it's not working... Topology: 7206 trunk vlanid 555 > MX80> MPLS CLOUD > MX480. 7206 (192.168.254.2) not pinging lt-interface on MX480 (192.168.254....
5
votes
3answers
8k views

Why does MPLS need an IGP (like OSPF) in order to work?

I saw a network using MPLS, BGP and OSPF as main network protocols. I understand that BGP was used to exchange traffic with another AS, and OSPF was used as Internal Gateway Protocol. So, why to use ...
5
votes
2answers
768 views

MPLS is used in whole internal network?

I configured MPLS/LDP in all interfaces of my testbed network. It is ran under IS-IS Level 1. I know and understand the benefits of MPLS (l3VPN or l2VPN). My question is : MPLS is used in whole ...
5
votes
3answers
1k views

Traceroute doesn't show one hop?

I have an interesting issue where my traceroute skips one hop on the way. I do not know why but it seems to be some kind of Juniper behaviour which I do not understand yet. Blue routers are Cisco ...
5
votes
1answer
520 views

Can 2 peering LSR generate same Label to same or different prefix and distribute among them?

Scope of the MPLS labels are within a router or within a interface right ?. So which means the peering neighbor LSR router can generate label values of its own.So say with below mpls topology. |LSR1|-...
5
votes
2answers
2k views

Migrating from VLANs to MPLS on JunOS [closed]

I'd like to see a worked example of recreating a regular common VLAN based topology using MPLS on Juniper hardware. In particular we will be using EX3xxx and EX4xxx for swicthing, though I don't think ...
5
votes
1answer
646 views

Cisco 7600 MUX-UNI on SRE IOS?

I know that MUX-UNI can only be configure on a 7600 running certain IOS version, SR and SX I believe. Does that not include SRE? Logged into a 7600 running 12.2(33)SRE9a, with the following ...
5
votes
1answer
1k views

juniper vlan-ccc vs ethernet-ccc for eompls

In juniper ethernet-ccc transports customer's vlan end to end. Does vlan-ccc also transport customer's vlan across as well?
5
votes
1answer
703 views

LDP VPLS - Packet behavior within bridge-groups and bridge-domains

I have a pair of ASR9k's that I plan on migrating to Juniper MX960's. Below is a piece of the configuration: l2vpn bridge group VPLS_1 bridge-domain 101 interface TenGigE0/2/0/0.101 ! ...
5
votes
1answer
2k views

RSVP between Cisco and Juniper

I can not configure the RSVP between Cisco6509 SUP2T and Juniper MX480. Prior to that set up the neighbor 3 without problems. Now that it is impossible ...I do not understand why :( scheme: Cisco t5/...
4
votes
1answer
4k views

load-balancing on congestion, OSPF over MPLS

I have a network of routers with two clients at both ends, as shown in the Figure below. All the routers use OSPF routing protocol over IP, and the three routers inside the "MPLS backbone" subnetwork ...
4
votes
2answers
531 views

Pseudowire and LSP

I can't understand the concept of PW (pseudowire). Does making a pseudowire mean that we are making a dedicate path with reserved resources for a service with defined requirements? so What are its ...
4
votes
4answers
321 views

Subnetting Issue with legacy network and poor planning

A client of mine is part of a bigger group of companies running a MPLS for connectivity. My Clients IP Address range is 192.168.13.0/24. We use this with DHCP and MASK of 255.255.255.0 and our ...
4
votes
2answers
1k views

Alternatives to GRE for multicast over MPLS?

I have an application that requires multicast across our MPLS WAN, and had been using GRE tunnels to facilitate this until recently when I replaced some aging edge routers with HP L3 switches. To my ...
4
votes
1answer
504 views

MPLS-TE backup LSP protection behavior

I'm trying to learn more about MPLS-TE, specifically how packets are routed once the TE LSP is set up. Most of the examples I could find that include the MPLS label stack shown are examples for Fast ...
4
votes
1answer
567 views

Need information on MPLS-TP, BHH & BFD

I am not able to find information on BHH; I got this link to draft-bhh-04 but was not able to understand the operation/function of BHH. If you guys have any info on above topics please let me know.
4
votes
1answer
148 views

Extending a subnet across a WAN link vs routing

probably a noob question but any help is appreciated. Question: What are the disadvantages of spanning L2 subnets across a WAN as opposed to a routed connection? Background: I've got a client who's ...
4
votes
2answers
803 views

Can I Use BGP as an IGP - Multisite w Redundant Layer 3 MPLS WANs

The requirements are Hundreds of sites. Each has a router and firewall and a switch stack. Layer 3 MPLS WAN with BGP to provider VRF. BGP as an IGP? iBGP Would you distribute a public ASN across all ...
4
votes
2answers
1k views

Connecting two OSPF sites both directly and via MPLS

Here at Stack Exchange, we recently added an MPLS link between data centers to supplement the VPN tunnels that we had been using up until now. The network looks like this: +-----------+ ...