1 / 8

VPLS Best Site ID

VPLS Best Site ID. Anshu Verma (anshuverma@juniper.net) Wen Lin (wlin@juniper.net) Rodny Molina (rodny.molina.maldonado@ericsson.com) John Drake (jdrake@juniper.net). VPLS Site ID Requirements. Site IDs configured on each VPLS PE must be unique per VPLS domain. Exception is multi-homing.

dbland
Download Presentation

VPLS Best Site ID

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. VPLS Best Site ID Anshu Verma (anshuverma@juniper.net) Wen Lin (wlin@juniper.net) Rodny Molina (rodny.molina.maldonado@ericsson.com) John Drake (jdrake@juniper.net)

  2. VPLS Site ID Requirements • Site IDs configured on each VPLS PE must be unique per VPLS domain. • Exception is multi-homing. • Site-IDs can be either provisioned or dynamically generated. • Exception is multi-homing as site-IDs need to be explicitly configured

  3. VPLS Site ID Problem • VPLS path selection mechanism picks the minimum site-id to determine the 'preferable' local site. • Whenever the elected site-id is declared down, the traffic to/from all other sites within the same VE is impacted as well. • Convergence period is impacted during transient intervals. • CPU cycles are spent in destroying/re-building affected PWs.

  4. VPLS Best Site ID Approach • When ‘best-site’ is enabled on PE, • It is elected as most preferable site by remote PEs • It remains permanently up regardless of access failure events. • Provides more provisioning flexibility. • Minimal traffic disruption for non-preferable sites in multi-site VPLS PEs during access-side failures. • No CPU cycles spent destroying and creating new PWs during failover events. • Backward compatible - Relies on their legacy/default site-election.

  5. Control Flag in Layer 2 Extended Community With reference to the Control Flags Bit Vector, the following bits in the Control Flags are defined; 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ |D|A|F|B|T|R|C|S| (Z = MUST Be Zero) +-+-+-+-+-+-+-+-+ D Defined in l2vpn-vpls-multihoming draft A Defined in l2vpn-auto-site-id draft F Defined in l2vpn-vpls-multihoming draft B When the bit value is 1, the PE receiving the label-block will deem the corresponding site as the most preferable site from the remote neighbor. When the bit value is 0, the PE receiving the label-block will rely on its legacy/default site-election algorithm. T/R Defined in l2vpn-fat-pw-bgp draft C Defined in [RFC4761] S Defined in [RFC4761]

  6. Best Site ID Approach (1) Send Label Adv: B-bit=1 • Receive NLRIs • Send a label-block adv with B-bit set. • Received label-block adv has: • [B-bit=1] Establish PW rooted at best-site • [B-bit=0] use legacy site-election (1) Send Label Adv: B-bit=1 (2) Honor B-bit from PE3 estbPW (2) Honor B-bit from PE3 estb PW (1) Send Label Adv: B-bit=1 PE1 (2) Honor B-bit estbPW, except PE4 PE2 PE3 PE5 PE4 BGP VPLS NLRI (1) Send Label Adv: B-bit=0 (2) Honor B-bit from PE3 estb PW

  7. VPLS Best Site ID Add-Ons • With ‘best-site’, no core-facing PW are ever torn down; previously learned MAC entries continue pointing to an invalid PW • Requires ‘Explicit-mac-flush’ mechanism to ensure that MAC-to-PW bindings are cleared during DF transition. • PE can request a remote PE to flush mac-entries by setting/unsetting F-bit in Layer2 control flags.

  8. VPLS Best Site ID • More details: draft-anshuverma-bess-vpls-best-site-id Questions?

More Related