If so, please summarise the areas of conflict in separate email to the Responsible Area Director. Are there normative references to IDs, where the IDs are not also ready for advancement or are otherwise in an unclear state? The different kinds of L2VPN may have different "provisioning models", i. Once configured, the provisioning information is distributed by a "discovery process".
When the discovery process is complete, a signaling protocol is automatically invoked. Any PW signaling protocol needs to have a method which allows each PW endpoint to identify the other; thus a PW signaling protocol will have the notion of an endpoint identifier. The semantics of the endpoint identifiers which the signaling protocol uses for a particular type of L2VPN are determined by the provisioning model.
This document specifies a number of L2VPN provisioning models, and further specifies the semantic structure of the endpoint identifiers required by each provisioning model. It discusses the way in which the endpoint identifiers are distributed by the discovery process, especially when the discovery process is based upon the Border Gateway Protocol BGP. In summary, we have all agreed that l2vpn-signaling is its own application and its use of Type-1 AII's is sufficient for it.
Another key difference is that l2vpn-signaling is focused on auto-discovery mechanisms for groups of PW's e. Could you please progress l2vpn-signaling, with the ultimate goal of publishing it as a PS? In summary, we have agreed that l2vpn-signaling is its own application and its use Type-1 AII's is sufficient for it. It also sounds like Mustapha had the same misunderstanding and raised an issue relative to auto-discovery of MS-PW's using Type-2 AII's, but which is orthogonal to l2vpn-signaling, and may or may not even be an issue.
No one else had any concerns and, in fact, both Florin and Mustapha did not intend to block l2vpn-signaling from moving forward. I'll also send a message to the list for the archives asking you to progress it to PS. Thanks, -shane.
However, I don't see the point in rushing a doc to the IESG if there are, what appears to be, significant concerns by list members with doing so. No one has suggested it on the list, nor am I sure that is even necessary at this point. Ultimately, I would like a little time to do some due diligence. Specifically: 1 For my own edification, I'd like to grab some time with Luca to understand the issue better, because it's not clear to me there is an issue.
Does this sound reasonable? Otherwise, I'll continue down the due diligence path and let you know what becomes of that. If you change the VE range, then the VC reprovisions and traffic is impacted as a result. Commands take effect after the device exits L2VFI configuration mode.
Enters router configuration mode for the specified routing process. Adds the IP address or peer group name of the neighbor in the specified autonomous system to the IPv4 multiprotocol BGP neighbor table of the local router. If the autonomous-system-number argument matches the autonomous system number specified in the router bgp command, the neighbor is an internal neighbor.
If the autonomous-system-number argument does not match the autonomous system number specified in the router bgp command, the neighbor is an external neighbor. In this example, the neighbor at Specifies the L2VPN address family and enters address family configuration mode. Enables the exchange of information with a BGP neighbor. Specifies that a communities attribute should be sent to a BGP neighbor. In this example, an extended communities attribute is sent to the neighbor at In this example, LDP signaling is suppressed for the neighbor at Exits address family configuration mode and returns to router configuration mode.
Exits router configuration mode and returns to privileged EXEC mode. Displays information about the configured VFI instances. Master Command List, All Releases. Multiprotocol Label Switching Command Reference. The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.
Access to most tools on the Cisco Support website requires a Cisco. If you have a valid service contract but do not have a user ID or password, you can register on Cisco. The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
The following commands were introduced or modified: autodiscovery bgp signaling bgp , debug bgp l2vpn vpls updates , neighbor suppress-signaling-protocol ldp , ve id , ve range , show bgp l2vpn vpls.
Thus, the SP must enforce limits on the number of routes accepted from a CE; this in turn requires the PE router to offer such control. An RR cannot keep all the advertised routes in every VPN since the number of routes will be too large. An RR could use a preconfigured list of Route-Targets for its inbound route filtering.
Finally, each PVC requires state in every transit switch. This reduces a large part of the provisioning burden. This need not still result in extra state in the SP network, i. On the other hand, the various sites of a Layer 3 VPN can connect to the SP with any supported media; for example, some sites may connect with Frame Relay circuits, and others with Ethernet. This comes at the cost of losing the Layer 3 independence.
A corollary to this is that the number of sites that can be in a Layer 2 VPN is determined by the number of Layer 2 circuits that the Layer 2 technology provides. This can be alleviated by manipulating the topology of the VPN. Moreover, with Layer 2 VPNs it is up to a customer to build and operate the whole network. With Layer 3 VPNs, a customer is just responsible for building and operating routing within each site, which is likely to be much simpler than building and operating routing for the whole VPN.
That, in turn, makes Layer 3 VPNs more suitable for customers who don't have sufficient routing expertise, again allowing the SP to provide added value. As mentioned later, multicast routing and forwarding is another value-added service that an SP can offer.
Multicast Routing There are two aspects to multicast routing that we will consider. On the protocol front, supporting IP multicast in a Layer 3 VPN requires PE routers to participate in the multicast routing instance of the customer, and thus keep some related state information.
The SP network just provides pipes to connect the CE routers; PEs are unaware whether the CEs run multicast or not, and thus do not have to participate in multicast protocols or keep multicast state information.
More complex solutions may require VPN multicast state in the SP network, but may significantly reduce the traffic in the SP network by delaying packet replication until needed. This has the advantage of distributing the burden of replication among the CEs rather than focusing it on the PE to which they are attached, and thus will scale better.
However, the CE-PE link will need to carry the multiple copies of multicast packets. Thus, just as in the case of unicast routing, the SP has the choice to offer a value-added service multicast routing and forwarding at some cost multicast state and packet replication using a Layer 3 VPN, or to keep it simple and use a Layer 2 VPN. Contributors The following contributed to this document.
For simplicity, we assume that a full-mesh topology is desired. See Figure 1 below. Suppose further that C wants to "over-provision" each current site, in expectation that the number of sites will grow to at least 10 in the near future. Note that the signalling mechanism discussed in Section 4 will allow a site to grow in terms of connectivity to other sites at a later point of time at the cost of additional signalling, i.
PE0 P CE3 CE4. Figure 1: Example Network Topology 3. Configuration The following sub-sections detail the configuration that is needed to provision the above VPN. For the purpose of exposition, we assume that the customer will connect to the SP with Frame Relay circuits.
While we focus primarily on the configuration that an SP has to do, Kompella, et al. Each side will run its own Layer 2 specific link management protocol, e. In general, a CE is configured with a list of circuits, all with the same Layer 2 encapsulation type, e. IP-only Layer 2 interworking allows a mix of Layer 2 encapsulation types. This is very important, as it decouples Kompella, et al. RDs do not have to be unique across the VPN. If all current members of the VPN are over-provisioned, i. Otherwise, the sites whose range doesn't include the new CE ID and wish to communicate directly with the new CE must have their ranges increased by allocating additional local circuits to incorporate the new CE ID.
The next step is ensuring that the new site has the required connectivity. This usually requires adding a new virtual circuit between the PE and CE; in most cases, this configuration is limited to the PE in question. The rest of the configuration is a local matter between the new CE and the PE to which it is attached. It bears repeating that the key to making additions easy is over- provisioning and the algorithm for mapping a CE-id to a DLCI which is used for connecting to the corresponding CE.
BGP was chosen as the means for exchanging L2 VPN information for two reasons: it offers mechanisms for both auto-discovery and signaling, and allows for operational convergence, as explained in Section 1. There are two modifications to the formating of messages. The first is that the set of Encaps Types carried in the L2-info extended community has been expanded to include those from Table 1.
The value of the Encaps Type field identifies the Layer 2 encapsulation, e. Note 2 : Having separate code points for Encaps Types allows specifying the trunk framing i. A simplex connection consists of the 3 segments: 1 the local access circuit between the source CE and the ingress PE, 2 the tunnel LSP between the ingress and egress PEs, and 3 the access circuit between the egress PE and the destination CE. Since it knows that status of its access circuit, and the status of the tunnel towards the remote PE, it can inform the remote PE of these two.
Similarly, the remote PE can inform the status of its access circuit to its local CE and the status of the tunnel to the first PE. The Type field of this TLV is 1. The Length field of the TLV specifies the length of the value field in bits. The Value field of this TLV is a bit-vector, each bit of which indicates the status of the PVC associated with the corresponding label in the label-block.
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