Hi Jorge, On 3/13/17, 9:04 AM, "BESS on behalf of Rabadan, Jorge (Nokia - US)" <[email protected] on behalf of [email protected]> wrote:
>Sami, > >About this one: > >³ 1. Why is receiving an extended community with both the P and B flags >set treated as a withdrawal, while it is ignored for the case when both >the P and B flags are clear? > >I agree both should be treated as a withdrawal, I will change the text.² > > >[JORGE] Sami, please correct this: > >³If the PE receives a route with both B and P > clear, it MUST treat the route as a withdrawal from the sender PE.² > >As you have in the following paragraph, flags P=B=0 is perfectly valid: > >³In multihoming single-active scenario for a given VPWS service > instance, the DF election should result in the Primary-elected PE for > the VPWS service instance advertising the P Flag set and the B Flag > clear, the Backup elected PE should advertise the P Flag clear and > the B Flag set, ****and the rest of the PEs in the same ES should >signal > both P and B Flags clear.****² Yes - but during DF election, you¹d want the former Primary or Backup advertisement to relinquish their respective roles. Now, there a multiple ways this could be accomplished and the -11 version on using the last advertised Primary or Backup should also result in the correct behavior. However, withdrawal would assure DF convergence as well as provide consistent behavior for both P and B Flags set and P and B Flags clear. Thanks, Acee > > >Let me know if I¹m missing something please. Don¹t want to hold the >progress, but this is important. >Thank you. >Jorge > > > >On 3/12/17, 8:24 PM, "Sami Boutros" <[email protected]> wrote: > > Hi Acee, > > Please find attached document with all comments addresses, if all >good will > Submit before the cut-off tomorrow. > > Please see comments inline. > On 3/12/17, 11:36 AM, "Acee Lindem (acee)" <[email protected]> wrote: > > > >Hi Sami, > > > >I think this version reads much better. I still have a couple >comments and > >questions. > > > > 1. Why is receiving an extended community with both the P and B >flags > >set treated as a withdrawal, while it is ignored for the case when >both > >the P and B flags are clear? > > I agree both should be treated as a withdrawal, I will change the >text. > > > 2. A related question is if a route with both the P and B flags >clear is > >ignored, won¹t this break DF election described on the bottom of >page 8? > >It says ³the rest of the PEs in the same ES should single both the P >and B > >Flags clear.² > > The DF election is between the PE(s) attached to the ES and has >nothing to do > With the remote PE receiving the routes from the PE(s) attached to >the ES. > The remote PE expect to receive one route with P Flag set and another >route > With with B flag set from another PE, all other routes received from >other PE(s) > Attached to the same ES are not needed, and hence can be treated as >withdrawal > Of previous routes from those Pe(s). > > > > > 3. Also, during DF election, is it implementation specific which >backup > >is chosen if multiple PEs advertise the B Flag set in their >respective > >extended communities? > > The DF election MUST always result in one Backup and One primary, >however > During transit more than one route with P or B Flags can be received. > > >Why isn¹t it the last one similar to the primary PE > >selection? > > Ok, to be consistent, will change the text to have the remote PE >select the > last advertising backup PE. > > > > > 4. Both VID and VLAN ID are used in the document. I didn¹t >research this > >but from the context it appears these are synonymous. If VID is >used, I¹d > >also add it to the ³Terminology² in 1.1. > > Ok. > > > > A few more Nits: > >*** draft-ietf-bess-evpn-vpws-11.txt.orig 2017-03-12 >13:56:46.000000000 > >-0400 > >--- draft-ietf-bess-evpn-vpws-11.txt 2017-03-12 14:34:06.000000000 >-0400 > >*************** > >*** 153,163 **** > > instance. As with the Ethernet Tag in standard EVPN, the VPWS >service > > instance identifier has uniqueness within an EVPN instance. > > > >! For EVPN routes, the Ethernet Tag ID are set to zero for >Port-based, > >! VLAN-based, and VLAN-bundle interface mode and it is set to >non-zero > >! Ethernet tag ID for VLAN-aware bundle mode. Conversely, for >EVPN- > > VPWS, the Ethernet tag ID in the Ethernet A-D route MUST be set >to a > >! non-zero value for all four service interface types. > > > > In terms of route advertisement and MPLS label lookup behavior, >EVPN- > > VPWS resembles the VLAN-aware bundle mode of [RFC7432] such >that when > >--- 153,163 ---- > > instance. As with the Ethernet Tag in standard EVPN, the VPWS >service > > instance identifier has uniqueness within an EVPN instance. > > > >! For EVPN routes, the Ethernet Tag IDs are set to zero for >Port-based, > >! VLAN-based, and VLAN-bundle interface mode and set to non-zero > >! Ethernet Tag IDs for VLAN-aware bundle mode. Conversely, for >EVPN- > > VPWS, the Ethernet tag ID in the Ethernet A-D route MUST be set >to a > >! non-zero value for all four service interface types. > > > > In terms of route advertisement and MPLS label lookup behavior, >EVPN- > > VPWS resembles the VLAN-aware bundle mode of [RFC7432] such >that when > >*************** > >*** 181,188 **** > > Ethernet frames are transported as is and the tags are not >altered. > > > > The MPLS label value in the Ethernet A-D route can be set to the > >! VXLAN Network Identifier (VNI) for VxLAN encap, and this VNI >may have > >! a global scope or local scope per PE and may also be made equal >to > > the VPWS service instance identifier set in the Ethernet A-D >route. > > > > The Ethernet Segment identifier encoded in the Ethernet A-D >per-EVI > >--- 181,188 ---- > > Ethernet frames are transported as is and the tags are not >altered. > > > > The MPLS label value in the Ethernet A-D route can be set to the > >! VXLAN Network Identifier (VNI) for VXLAN encap, and this VNI >may have > >! a global scope or local scope per PE and may also be equal to > > the VPWS service instance identifier set in the Ethernet A-D >route. > > > > The Ethernet Segment identifier encoded in the Ethernet A-D >per-EVI > >*************** > >*** 312,321 **** > > > > 2.3 VLAN-Aware Bundle Service Interface > > > >! Contrary to EVPN, in EVPN-VPWS this service interface maps to >VLAN- > > based service interface (defined in section 2.1) and thus this > > service interface is not used in EVPN-VPWS. In other words, if >one > >! tries to define data-plane and control plane behavior for this > > service interface, one would realize that it is the same as >that of > > VLAN-based service. > > > >--- 312,321 ---- > > > > 2.3 VLAN-Aware Bundle Service Interface > > > >! Contrary to EVPN, in EVPN-VPWS this service interface maps to a >VLAN- > > based service interface (defined in section 2.1) and thus this > > service interface is not used in EVPN-VPWS. In other words, if >one > >! tries to define data plane and control plane behavior for this > > service interface, one would realize that it is the same as >that of > > VLAN-based service. > > > >*************** > >*** 326,332 **** > > signal VPWS services. The Ethernet Segment Identifier field is >set to > > the customer ES and the Ethernet Tag ID 32-bit field MUST be >set to > > the VPWS service instance identifier value. The VPWS service >instance > >! identifier value MAY be set to a 24-bit value, when 24-bit >value is > > used, it MUST be right aligned. For both EPL and EVPL services >using > > a given VPWS service instance, the pair of PEs instantiating >that > > VPWS service instance will each advertise a per-EVI Ethernet A-D > >--- 326,332 ---- > > signal VPWS services. The Ethernet Segment Identifier field is >set to > > the customer ES and the Ethernet Tag ID 32-bit field MUST be >set to > > the VPWS service instance identifier value. The VPWS service >instance > >! identifier value MAY be set to a 24-bit value and when a 24-bit >value > >is > > used, it MUST be right aligned. For both EPL and EVPL services >using > > a given VPWS service instance, the pair of PEs instantiating >that > > VPWS service instance will each advertise a per-EVI Ethernet A-D > >*************** > >*** 354,361 **** > > > > 3.1 EVPN Layer 2 attributes extended community > > > >! This draft proposes a new extended community [RFC4360], to be > >! included with the per-EVI Ethernet A-D route. This attribute is > > mandatory if multihoming is enabled. > > > > +------------------------------------+ > >--- 354,361 ---- > > > > 3.1 EVPN Layer 2 attributes extended community > > > >! This document defines an extended community [RFC4360], to be > >! included with per-EVI Ethernet A-D routes. This attribute is > > mandatory if multihoming is enabled. > > > > +------------------------------------+ > >*************** > >*** 423,429 **** > > > > In a multihoming all-active scenario, there is no DF election, >and > > all the PEs in the ES that are active and ready to forward >traffic > >! to/from the CE will set the P Flag. A remote PE will do >per-flow load > > balancing to the PEs that set the P Flag for the same Ethernet >Tag > > and ESI. The B Flag in control flags SHOULD NOT be set in the > > multihoming all-active scenario and MUST be ignored by receiving > >--- 423,429 ---- > > > > In a multihoming all-active scenario, there is no DF election, >and > > all the PEs in the ES that are active and ready to forward >traffic > >! to/from the CE will set the P Flag. A remote PE will do >per-flow load- > > balancing to the PEs that set the P Flag for the same Ethernet >Tag > > and ESI. The B Flag in control flags SHOULD NOT be set in the > > multihoming all-active scenario and MUST be ignored by receiving > >*************** > >*** 493,499 **** > > > > All PEs and ASBRs are enabled for the EVPN SAFI and exchange >per-EVI > > Ethernet A-D routes, one route per VPWS service instance. For >inter- > >! AS option B, the ASBRs re-advertise these routes with NEXT_HOP > > attribute set to their IP addresses as per [RFC4271]. The link > > between the CE and the PE is either a C-tagged or S-tagged >interface, > > as described in [802.1Q], that can carry a single VLAN tag or >two > >--- 493,499 ---- > > > > All PEs and ASBRs are enabled for the EVPN SAFI and exchange >per-EVI > > Ethernet A-D routes, one route per VPWS service instance. For >inter- > >! AS option B, the ASBRs re-advertise these routes with the >NEXT_HOP > > attribute set to their IP addresses as per [RFC4271]. The link > > between the CE and the PE is either a C-tagged or S-tagged >interface, > > as described in [802.1Q], that can carry a single VLAN tag or >two > >*************** > >*** 570,576 **** > > Finally, EVPN may employ data plane egress link protection >mechanisms > > not available in VPWS. This can be done by the primary PE (on >local > > AC down) using the label advertised in the per-EVI Ethernet A-D >route > >! by the backup PE to encapsulate the traffic and direct it to >backup > > PE. > > > > 6 Failure Scenarios > >--- 570,576 ---- > > Finally, EVPN may employ data plane egress link protection >mechanisms > > not available in VPWS. This can be done by the primary PE (on >local > > AC down) using the label advertised in the per-EVI Ethernet A-D >route > >! by the backup PE to encapsulate the traffic and direct it to the > >backup > > PE. > > > > 6 Failure Scenarios > >*************** > >*** 592,600 **** > > For a faster convergence in multi-homed scenarios with either >Single- > > Active Redundancy or All-active redundancy, a mass withdraw >technique > > is used. A PE previously advertising a per-ES Ethernet A-D >route, can > >! withdraw this route signaling to the remote PEs to switch all >the > > VPWS service instances associated with this multi-homed ES to >the > >! backup PE > > > > 7 Acknowledgements > > > >--- 592,600 ---- > > For a faster convergence in multi-homed scenarios with either >Single- > > Active Redundancy or All-active redundancy, a mass withdraw >technique > > is used. A PE previously advertising a per-ES Ethernet A-D >route, can > >! withdraw this route by signaling to the remote PEs to switch >all the > > VPWS service instances associated with this multi-homed ES to >the > >! backup PE. > > > > 7 Acknowledgements > > Thanks, > > Sami > > > > >_______________________________________________ >BESS mailing list >[email protected] >https://www.ietf.org/mailman/listinfo/bess _______________________________________________ BESS mailing list [email protected] https://www.ietf.org/mailman/listinfo/bess
