Jump to content

Layer 2 MPLS VPN: Difference between revisions

Add links
From Wikipedia, the free encyclopedia
Browse history interactively
← Previous edit
Content deleted Content added
VisualWikitext
disambiguate
m unnecessary red link
 
(21 intermediate revisions by 16 users not shown)
Line 1: Line 1:
{{Unreferenced|date=October 2008}}
{{Refimprove|date=February 2013}}
[[File:L2 MPLS VPN en.svg|300px|thumb|Logical View of a Layer 2 MPLS VPN.]]

A '''Layer 2 MPLS VPN''' is a term in [[computer networking]]. It is a method that [[Internet service providers]] use to segregate their network for their customers, to allow them to transmit data over an [[IP network]]. This is often sold as a service to businesses.
A '''Layer 2 MPLS VPN''' is a term in [[computer networking]]. It is a method that [[Internet service providers]] use to segregate their network for their customers, to allow them to transmit data over an [[IP network]]. This is often sold as a service to businesses.


Layer 2 VPNs are a type of [[Virtual Private Network]] (VPN) that uses [[Multiprotocol Label Switching|MPLS]] labels to transport data. The communication occurs between [[Router (computing)|routers]] that are known as ''Provider Edge'' routers (PEs), as they sit on the edge of the provider's network, next to the customer's network.
Layer 2 VPNs are a type of [[Virtual Private Network]] (VPN) that uses [[Multiprotocol Label Switching|MPLS]] labels to transport data. The communication occurs between [[Router (computing)|routers]] that are known as [[PE router|Provider Edge routers]] (PE routers), as they sit on the edge of the provider's network, next to the customer's network.


Internet providers who have an existing [[Layer 2]] network (such as [[Asynchronous Transfer Mode|ATM]] or [[Frame Relay]])) may choose to use these VPNs instead of the other common MPLS VPN, [[Network Layer|Layer 3]]. There is no one [[IETF]] standard for Layer 2 MPLS VPNs. Instead, two methodologies may be used. Both methods use MPLS Headers to [[Encapsulation (networking)|encapsulate]] data. However, they differ in the way they transport data.
Internet providers who have an existing [[Layer 2]] network (such as [[Asynchronous Transfer Mode|ATM]] or [[Frame Relay]]) may choose to use these VPNs instead of the other common MPLS VPN, [[Network Layer|Layer 3]]. There is no one [[IETF]] standard for Layer 2 MPLS VPNs. Instead, two methodologies may be used. Both methods use a standard MPLS header to [[Encapsulation (networking)|encapsulate]] data. However, they differ in their signaling protocols.


==Types of Layer 2 MPLS VPNs==
==Types of Layer 2 MPLS VPNs==

=== BGP-based ===
=== BGP-based ===
The BGP-based type is based on a draft specification by [[Kireeti Kompella]], from [[Juniper Networks]]. It uses the [[Border Gateway Protocol]] (BGP) as the mechanism for PE routers to communicate with each other about their customer connections. Each router connects to a central cloud, using BGP. This means that when new customers are added (usually to new routers), the existing routers will communicate with each other, via BGP, and automatically add the new customers to the service.
The BGP-based type is based on the informational [[Request For Comment|RFC]] 6624 by Kireeti Kompella from [[Juniper Networks]]. It uses the [[Border Gateway Protocol]] (BGP) as the mechanism for PE routers to communicate with each other about their customer connections. Each router connects to a central cloud, using BGP. This means that when new customers are added (usually to new routers), the existing routers will communicate with each other, via BGP, and automatically add the new customers to the service.<ref>{{cite web |title=Layer 2 Virtual Private Networks Using BGP for Auto-Discovery and Signaling |url=https://datatracker.ietf.org/doc/html/rfc6624 |website=IETF |access-date=25 January 2024}}</ref>


=== LDP-based ===
=== LDP-based ===
The second type is based on a draft specification by Luca Martini from [[Cisco Systems]]. This method is also known as a ''Layer 2 circuit''. It uses the [[Label Distribution Protocol]] (LDP) to communicate between PE routers. In this case, every router will connect to every other router in the VPN, which differs from the BGP-based methodology.
The second type is based on the [[Internet Standard]] RFC 8077<ref group=Note>Obsoletes the previous identically named [https://datatracker.ietf.org/doc/html/rfc4447 RFC 4447]</ref> by Chandan Mishra from [[Cisco Systems]]. This method is also known as a ''Layer 2 circuit''. It uses the [[Label Distribution Protocol]] (LDP) to communicate between PE routers. In this case, every LDP-speaking router will exchange FECs (forwarding equivalence classes) and establish [[Label-switched path|LSP]]s with every other LDP-speaking router on the network (or just the other PE router, in the case when LDP is tunnelled over [[RSVP-TE]]), which differs from the BGP-based methodology. The LDP-based style of layer 2 VPN defines new [[Type–length–value|TLV]]s and parameters for LDP to aid in the signaling of the VPNs.<ref>[http://tools.ietf.org/html/rfc8077 Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP)]</ref>
The LDP-based L2 VPN also defined the auto-discovery mechanism such as [BGP-DISC], [Radius-DISC] for PE auto-discovery.


== Methods used by Vendors ==
== Vendor implementations ==
* Alcatel-Lucent: LDP based
* Alcatel-Lucent: LDP based
* [[Foundry Networks]]: LDP-based (NetIron XMR Series, NetIron MLX Series)
* [[Foundry Networks]]: LDP-based (NetIron XMR Series, NetIron MLX Series)
* [[Juniper Networks]]: BGP-based (MX/M/T/J-series)
* [[Juniper Networks]]: BGP-based (MX/M/T/J-series)
* Juniper Networks: LDP-based (MX/M/T/J/E-series)
* Juniper Networks: LDP-based (MX/M/T/J/E-series)
* Cisco Systems: LDP-based
* Cisco Systems: LDP-based (IOS)
* Cisco Systems: LDP-based and BGP-based (IOS XR)
* Cisco Systems: LDP-Based [BGP-DISC][http://www.cisco.com/en/US/docs/ios/12_2sr/12_2srb/feature/guide/fs_vpls.html]
* Cisco Systems: LDP-Based [BGP-DISC][http://www.cisco.com/en/US/docs/ios/12_2sr/12_2srb/feature/guide/fs_vpls.html]
* MRV communications [http://www.mrv.com]: LDP-based
* MRV communications [http://www.mrv.com]: LDP-based
Line 26: Line 27:
* [[Ericsson]] (formerly [[Redback Networks]]): LDP-based
* [[Ericsson]] (formerly [[Redback Networks]]): LDP-based
* Huawei Technologies: LDP-based & BGP-based (NE/S-series)
* Huawei Technologies: LDP-based & BGP-based (NE/S-series)
* ZTE:LDP-based & BGP-based(ZXCTN6000/9000 series, ZXR10 series)
* ZTE:LDP-based & BGP-based (ZXCTN6000/9000 series, ZXR10 series)

==Notes==
{{reflist|group=Note}}

==References==
{{reflist}}


{{Compu-network-stub}}
[[Category:MPLS networking]]
[[Category:MPLS networking]]

Latest revision as of 09:46, 25 January 2024

Logical View of a Layer 2 MPLS VPN.

A Layer 2 MPLS VPN is a term in computer networking. It is a method that Internet service providers use to segregate their network for their customers, to allow them to transmit data over an IP network. This is often sold as a service to businesses.

Layer 2 VPNs are a type of Virtual Private Network (VPN) that uses MPLS labels to transport data. The communication occurs between routers that are known as Provider Edge routers (PE routers), as they sit on the edge of the provider's network, next to the customer's network.

Internet providers who have an existing Layer 2 network (such as ATM or Frame Relay) may choose to use these VPNs instead of the other common MPLS VPN, Layer 3. There is no one IETF standard for Layer 2 MPLS VPNs. Instead, two methodologies may be used. Both methods use a standard MPLS header to encapsulate data. However, they differ in their signaling protocols.

Types of Layer 2 MPLS VPNs

[edit]

BGP-based

[edit]

The BGP-based type is based on the informational RFC 6624 by Kireeti Kompella from Juniper Networks. It uses the Border Gateway Protocol (BGP) as the mechanism for PE routers to communicate with each other about their customer connections. Each router connects to a central cloud, using BGP. This means that when new customers are added (usually to new routers), the existing routers will communicate with each other, via BGP, and automatically add the new customers to the service.[1]

LDP-based

[edit]

The second type is based on the Internet Standard RFC 8077[Note 1] by Chandan Mishra from Cisco Systems. This method is also known as a Layer 2 circuit. It uses the Label Distribution Protocol (LDP) to communicate between PE routers. In this case, every LDP-speaking router will exchange FECs (forwarding equivalence classes) and establish LSPs with every other LDP-speaking router on the network (or just the other PE router, in the case when LDP is tunnelled over RSVP-TE), which differs from the BGP-based methodology. The LDP-based style of layer 2 VPN defines new TLVs and parameters for LDP to aid in the signaling of the VPNs.[2]

Vendor implementations

[edit]
  • Alcatel-Lucent: LDP based
  • Foundry Networks: LDP-based (NetIron XMR Series, NetIron MLX Series)
  • Juniper Networks: BGP-based (MX/M/T/J-series)
  • Juniper Networks: LDP-based (MX/M/T/J/E-series)
  • Cisco Systems: LDP-based (IOS)
  • Cisco Systems: LDP-based and BGP-based (IOS XR)
  • Cisco Systems: LDP-Based [BGP-DISC][1]
  • MRV communications [2]: LDP-based
  • Lucent Technologies (formerly Riverstone Networks): LDP-based
  • Ericsson (formerly Redback Networks): LDP-based
  • Huawei Technologies: LDP-based & BGP-based (NE/S-series)
  • ZTE:LDP-based & BGP-based (ZXCTN6000/9000 series, ZXR10 series)

Notes

[edit]
  1. ^ Obsoletes the previous identically named RFC 4447

References

[edit]
  1. ^ "Layer 2 Virtual Private Networks Using BGP for Auto-Discovery and Signaling". IETF. Retrieved 25 January 2024.
  2. ^ Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP)
Retrieved from "https://en.wikipedia.org/enwiki/w/index.php?title=Layer_2_MPLS_VPN&oldid=1198899573"