1 / 13

Labeled ARP

Labeled ARP. Kireeti Kompella Balaji Rajagopalan IETF 89. Acknowledgments: Shane Amante Thomas Morin Luyuan Fang The Juniper “MPLS-in-DC” team. Problem Statement (DC). Overlays are all the rage in the data center

saki
Télécharger la présentation

Labeled ARP

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Labeled ARP Kireeti Kompella BalajiRajagopalan IETF 89 Acknowledgments: Shane Amante Thomas Morin Luyuan Fang The Juniper “MPLS-in-DC” team

  2. Problem Statement (DC) • Overlays are all the rage in the data center • except that we’ve been doing overlays/underlays with MPLS pretty much since 1997 • The DC overlays start at the host (server) • which requires true “plug-and-play” operation • To have an MPLS underlay network, the host must be part of the underlay • this draft is about making that easy and p-n-p

  3. Problem Statement (access) • Many have asked that MPLS start at the access node (DSLAM, OLT, cell-site gateway) • “Seamless MPLS” has suggested the use of LDP DoD (Downstream on Demand) for this • There haven’t been many implementations of LDP DoD from access node vendors • Maybe a different approach/protocol for the same functionality is needed

  4. Overlays/Underlays VCs Single VP ~64K end points ATM overlay (simple) core: no endpoint state edge: lots of state O(10^4) VPNs, O(10^7) addresses PE P LSP MPLS overlay (sophisticated) core: no VPN or VPN address state edge: lots of state

  5. Overlay/Underlay Data Plane • Commodity chips implemented the MPLS data plane about a decade ago • Now, some have implemented just one of a largish crop of new overlay encapsulations • And, as we speak, there is yet another one

  6. Overlay/Underlay Control Planes • MPLS has a very sophisticated, robust, scalable and interoperable control plane • Various types of hierarchy are supported • {BGP, T-LDP} [overlay] over {LDP, RSVP-TE, LDP/RSVP-TE} [underlay] • None of the new overlays encapsulations have well-specified, interoperable control planes for either the overlay or the underlay • BGP for an overlay (EVPN/IPVPN over VXLAN) is just being proposed

  7. Can the MPLS Control Plane Be Too Sophisticated (in Some Cases)? ToRs VMs VMs VMs hosts 1000s of nodes 10^7s 100000s Can’t have a flat IGP with so many hosts LDP DoD with static routing is a possibility, but not ideal Absolutely has to be plug-and-play – new hosts are added at a high rate

  8. Proxy ARP recap IP1 IP2 T2 … T1 H1 H2 MAC1 1) Hey, give me a hardware address (of type Ethernet) that I can use to reach IP2 2) T1 has a route to H2 3) You can use MAC1

  9. Labeled ARP (1) LFIB L3: pop & send to H2 IP1 IP2 LDP LDP T2 … T1 H1 H2 Label L2 to reach IP2 Label L3 to reach IP2 T1 has a label (L2) to reach H2 T2 leaks its hosts’ routes (here IP2) into LDP (with label L3)

  10. Labeled ARP (2) LFIB L3: pop & send to H2 LFIB L1  L2 IP1 IP2 L1 L2 L3 T2 … T1 H2 H1 MAC1 1) Hey, give me a hardware address (of type MPLSoEthernet) that I can use to reach IP2 2) T1 allocates L1 for H1 to reach H2, adds an LFIB entry to swap L1 with L2 3) You can use MAC1:L1 Functionality is very much like LDP DoD. However, ARP code is plug-and-play and ubiquitous. Note: new h/w type means that this code is separate from “normal” ARP code

  11. Use Case 1:Egress Peering Traffic Engineering RIB: Prefix1: nh IP1 Prefix2: nh IP2 Direct traffic to prefix1 to ISP1 ISP1 Data Center IP1 Content Server Intra DC Network Peering link to ISP1 Internet Peering link to ISP2 ISP2 IP2 Direct traffic to prefix2 to ISP2 Use MPLS underlay for traffic steering CS L-ARPs for IP1/IP2 to get required labels Bonus: DC switches carry “a few” MPLS LSPs rather than full Internet routing

  12. Use Case 2: MPLS Underlay for DCs(with VRFs/E-VPNs for overlay) IP1 IP2 L-ARP L-ARP VM2 LDP LDP T2 … T1 H1 H2 VM1 BGP To reach VM2, use VL2 with IP2 as the next hop BGP VM1 wants to talk to VM2 (same VPN). H1 resolves IP2 using L-ARP. Then, packets from VM1 to VM2 are encapsulated with outer label L1 and inner label VL2 RR

  13. Next Steps • There are a few problems to resolve • Section 4: “For Future Study” • We have some of the answers, but not all • Philosophy: keep L-ARP client simple • Will republish the draft with proper filename • We will publish a use cases draft, if desired • We have running code (for Linux hosts) • User space daemon, independent of Ethernet ARP • Now, all we need is rough consensus :)

More Related