Spatially aware sublayer support of VRRP. Marc Holness, Nortel Networks IEEE WG b SG San Antonio, Texas November, 2004

Transcription

1 Spatially aware sublayer support of VRRP Marc Holness, Nortel Networks IEEE WG b SG San Antonio, Texas November, 2004 Marc Holness - 1

2 Agenda Objectives Problem overview Solution overview Spatially aware sublayer operations Marc Holness - 2

3 Terminology and terms Directed transmissions Refers to a RPR source station transmitting to a designated (unicast) destination address on the ring Undirected transmission Refers to a RPR source station flooding a frame over the ring Remote address A MAC address that is not local to the ring (i.e., not a local RPR station MAC address) SAS Spatially aware sublayer VRRP Virtual router redundancy protocol (as specified in RFC 3768) VMAC Virtual MAC (or VRRP group) Marc Holness - 3

4 Objectives Outline how the spatially aware sublayer (SAS) can support VRRP applications Marc Holness - 4

5 Problem overview Typical WAN Host 1 -> Host 2 data traffic Router C Host 1 Default gateway = Router B Router D San Antonio New York San Jose Host 1 uses default gateway to get to Host 2 Marc Holness - 5

6 Problem overview Typical WAN Router C Host 1 Default gateway = Router B Router D San Antonio New York San Jose If fault occurs at (or link to ), communication from Host 1 to Host 2 is interrupted Marc Holness - 6

7 Solution overview A solution that allows for fast convergence and does not affect current host implementations is required VRRP is born! Marc Holness - 7

8 VRRP basics Physical view Logical view Host 1 Default gateway = VR 1 master Virtual router ID 1 Host 1 Default gateway = Virtual router ID 1 Virtual MAC address : 00:00:5E:00:01:0101 Virtual IP address : VR 1 backup VR 1 backup Virtual Router ID 1 Virtual MAC address - 00:00:5E:00:01:0101 Virtual IP address Marc Holness - 8

9 VRRP most common implementation Physical view Virtual router ID 1 Logical view Host 1 Default gateway = Host 2 Default gateway = VR 1 master VR 2 backup VR 2 master VR 1 backup Host 1 Default gateway = Host 2 Default gateway = Virtual router ID 2 Virtual router ID 1 Virtual router ID 2 Virtual MAC address : 00:00:5E:00:01:0101 Virtual IP address: Virtual MAC address : 00:00:5E:00:01:0202 Virtual IP address: Virtual router ID 1 Virtual router ID 2 Marc Holness - 9

10 VRRP operation Normal operation VRRP Adv Msg, Prio 255 VR 1 master VR 2 backup, priority 150 VR 2 master down interval timer Host 1 Default gateway = Host 2 Default gateway = VRRP Adv Msg, Prio VR 2 master VR 1 backup, priority 160 VR 1 master down interval timer VR 2 backup, priority 100 VR 1 backup, priority 120 Marc Holness - 10

11 VRRP operation Failure operation (master down interval time out) Host 1 Default gateway = VRRP Adv Msg, Prio VR 1 master VR 2 backup, priority Host 2 Default gateway = VR 2 master VR 1 backup, priority 160 VR 2 backup, priority 100 VR 1 backup, priority 120 Marc Holness - 11

12 VRRP operation Failure operation (election process) VR 1 master VR 2 backup, priority 150 Host 1 Default gateway = Host 2 Default gateway = VRRP Adv Msg, Prio VRRP Adv Msg, Prio VR 2 master VR 1 backup, priority 160 VR 2 backup, priority 100 VR 1 backup, priority 120 Marc Holness - 12

13 VRRP operation Failure operation - and the winner is Host 1 Default gateway = Gratuitous ARP Msg VRRP Adv Msg, Prio VR 2 backup, priority Host 2 Default gateway = VR 2 master VR1 master, priority 160 VR 2 backup, priority 100 VR 1 backup, priority 120 Marc Holness - 13

14 VRRP advertisement message Sent periodically by master router in virtual router group (i.e., VRID) - Received and processed by backup routers in virtual router group DA = MAC group address SA = 00:00:5E:00:01:<VRID> IP SA = VR master IP address IP DA = VRRP packet Frame check sequence Marc Holness - 14

15 Gratuitous ARP message Sent by master router of virtual router group (i.e., VRID) at startup and when master router fail over occurs - Host devices receiving gratuitous ARP update ARP cache tables - Intermediate bridging devices, if present, will update FDB entries associated with virtual router master interface MAC address and received port DA = FF:FF:FF:FF:FF:FF SA = VR master interface MAC ARP packet VR MAC VR master interface IP Frame check sequence Marc Holness - 15

16 Host ARP request message Sent by host at startup time to discover MAC address of virtual router master - Intermediate bridging devices, if present, will update FDB entries associated with host MAC address and received port DA = FF:FF:FF:FF:FF:FF SA = Host MAC ARP packet Default gateway IP address Frame check sequence Marc Holness - 16

17 Host ARP reply message Sent by virtual router master in response to host ARP request - Intermediate bridging devices, if present, will update FDB entries associated with virtual router interface MAC address and received port DA = Host MAC SA = VR interface MAC ARP packet VR MAC address VR interface IP address Frame check sequence Marc Holness - 17

18 RPR and VRRP network references (1) Virtual router ID 1 VR1 master VR2 backup Router B Virtual router ID 2 Bridge 1 Bridge 2 VR2 master VR1 backup Host 1 Host 2 Host 3 Host 4 Marc Holness - 18

19 RPR and VRRP network references (2) Virtual router ID 1 VR1 master VR2 backup Router B VR2 master VR1 backup Virtual router ID Host 1 Host 2 Host 3 Host 4 Marc Holness - 19

20 RPR and VRRP network references (3) Virtual router ID 1 Router B VR1 master VR2 backup VR2 master VR1 backup Virtual router ID 2 Bridge 3 Bridge 4 Bridge 1 Bridge Host 1 Host 2 Host 3 Host 4 Marc Holness - 20

21 support of VRRP Virtual MAC (i.e., 00:00:5E:00:01:<VRID>) used by VRRP does not represent an address associated with a RPR station - Consequently MAC will, by default, flood frames with this MAC address - Results in lack of spatial reuse and poor bandwidth utilization over the ring Marc Holness - 21

22 802.17b SAS interactions with VRRP Marc Holness - 22

23 SAS support of VRRP Advertisement messages over b Virtual router ID 1 VR1 master Router B VR1 backup SAS Associate Associate VMAC VMAC with with RPR RPR station station MAC MAC attachment attachment Frames Frames transmitted transmitted to to VMAC VMAC (which (which is is considered considered a a remote remote address) address) can can now now be be associated associated with with an an RPR RPR station station MAC, MAC, resulting resulting in in directed directed transmissions transmissions and and achieving achieving spatial spatial reuse reuse over over RPR RPR Marc Holness - 23

24 SAS support of VRRP Gratuitous ARP messages over b Virtual router ID 1 VR1 master Router B Bridge 3 Bridge 4 Bridge 1 Bridge 2 VR1 backup Host 1 Host 2 Host 3 Host 4 SAS Associate Associate VR VR master master interface interface MAC MAC (remote (remote address) address) with with RPR RPR station station MAC MAC attachment attachment Frames Frames transmitted transmitted to to the the VR VR master master interface interface MAC MAC (remote (remote address) address) can can now now be be associated associated with with an an RPR RPR station station MAC, MAC, resulting resulting in in directed directed transmissions transmissions and and achieving achieving spatial spatial reuse reuse over over RPR RPR Marc Holness - 24

25 SAS support of VRRP Host ARP request messages over b Virtual router ID 1 VR1 master Router B Bridge 1 Bridge 2 VR1 backup SAS Associate Associate host host MAC MAC address address (remote (remote address) address) with with RPR RPR station station MAC MAC attachment attachment Frames Frames transmitted transmitted to to the the host host MAC MAC address address (remote (remote address) address) can can now now be be associated associated with with an an RPR RPR station station MAC, MAC, resulting resulting in in directed directed transmissions transmissions and and achieving achieving spatial spatial reuse reuse over over RPR RPR Host 1 Host 2 Host 3 Host 4 Marc Holness - 25

26 SAS support of VRRP Host ARP reply messages over b Virtual router ID 1 VR1 master Router B Bridge 3 Bridge 4 Bridge 1 Bridge 2 VR1 backup Host 1 Host 2 Host 3 Host 4 SAS Associate Associate VR VR master master interface interface MAC MAC (remote (remote address) address) with with RPR RPR station station MAC MAC attachment attachment Frames Frames transmitted transmitted to to the the VR VR master master interface interface MAC MAC (remote (remote address) address) can can now now be be associated associated with with an an RPR RPR station station MAC, MAC, resulting resulting in in directed directed transmissions transmissions and and achieving achieving spatial spatial reuse reuse over over RPR RPR Marc Holness - 26

27 SAS support of VRRP VRRP normal operation Virtual router ID 1 VR1 master Router B Bridge 1 Bridge 2 VR1 backup Host 1 Host 2 Host 3 Host 4 SAS Data Data transmissions transmissions from from Host Host 11 to to off-net off-net host host via via VR VR master master router router will will result result in in SAS SAS DB DB lookup lookup of of VMAC VMAC - - RPR RPR station station MAC MAC entry entry found found in in SAS SAS DB DB will will result result in in directed directed transmissions transmissions and and thus thus achieve achieve spatial spatial reuse reuse over over RPR RPR Data Data transmissions transmissions from from VR VR master master router router to to Host Host 11 will will result result in in SAS SAS DB DB lookup lookup of of Host Host 11 MAC MAC address address (remote) (remote) - - RPR RPR station station MAC MAC entry entry found found in in SAS SAS DB DB will will result result in in directed directed transmissions transmissions and and thus thus achieve achieve spatial spatial reuse reuse over over RPR RPR Marc Holness - 27

28 Summary SAS supports VRRP applications over RPR - Provides spatial reuse improvements - No additional RPR configuration required - VMAC to RPR station MAC associations are auto-learned - Supports various VRRP network configurations involving RPR, routers, bridges, and hosts Marc Holness - 28

29 Backup Marc Holness - 29

30 VRRP/RPR packet walk-thru Virtual Router ID 1 Router B VR1 Master VR2 Backup VR2 Master VR1 Backup Virtual Router ID 2 Bridge 1 Bridge Host 1 Host 2 Host 3 Host 4 VRRP startup VRRP startup 1. VR1 master (RouterA) sends advertisement message - VR1 backup (RouterB) receives advertisement message and resets Master_Down_Timer - SAS in RPR RouterB, RPR Bridge1 & RPR Bridge2 associates VMAC1 with RouterA MAC (MAC RA ) - Bridge1 forwards VRRP advertisement message to Host1 and Host2 - VR1 master (RouterA) sends advertisement message every Advertisement_Interval (e.g., 1 sec) 2. VR1 master (RouterA) broadcast gratuitous ARP message - SAS in RPR RouterB, RPR Bridge1 & RPR Bridge2 associates VR master interface MAC with RouterA MAC (MAC RA ) - Bridge1 forwards gratuitous ARP to Host1 and Host2 - Host1 and Host2 updates ARP cache table Marc Holness - 30

31 VRRP/RPR packet walk-thru Virtual Router ID 1 Router B VR1 Master VR2 Backup VR2 Master VR1 Backup Virtual Router ID 2 Bridge 1 Bridge Host startup Host startup 3. Host1 broadcast ARP request message - RPR Bridge1 floods frame over RPR - SAS in RPR RouterA & RouterB, RPR Bridge1 & RPR Bridge2 associates Host1 MAC (MAC H1 ) with RPR Bridge1 MAC (MAC B1 ) - VR1 master (RouterA) receives ARP request and processes message 4. VR1 master (RouterA) responds to ARP request with ARP reply message - Host1 updates ARP cache table Host 1 Host 2 Host 3 Host 4 Marc Holness - 31

32 VRRP/RPR packet walk-thru SAS DB Virtual Router ID 1 Remote MAC MAC H1 VID RPR MAC MAC B1 Router B VR1 Master VR2 Master VR2 Backup VR1 Backup MAC H2 MAC B1 Virtual Router ID 2 Bridge 1 Bridge SAS DB Remote MAC VID RPR MAC Host 1 Host 2 Host 3 Host 4 VMAC MAC RA After VRRP initialization signaling and Host ARP process, the SAS S data bases are updated. Marc Holness - 32

33 VRRP/RPR packet walk-thru Virtual Router ID 1 Router B VR1 Master VR2 Backup VR2 Master VR1 Backup Virtual Router ID 2 Bridge 1 Bridge Host 1 Host 2 Host 3 Host 4 Normal operation 5. Host1 sends message to off-net Host via VR1 (using VMAC in destination address) - RPR Bridge1 MAC indexes SAS DB using VMAC and discovers RPR MAC address MAC RA is RPR destination target address to perform directed transmission to RPR station RouterA 6. Off-net Host messages Host1 via VR1 master (RouterA) - RPR RouterA MAC indexes SAS DB using MAC H1 and discovers RPR MAC address MAC B1 is RPR destination target address to perform directed transmission to RPR station Bridge1 - Bridge1 dispatches packet to Host1 SAS provides spatial reuse over RPR involving VRRP interactions. Marc Holness - 33

34 VRRP/RPR packet walk-thru Virtual Router ID 1 Router B VR1 Master VR2 Backup VR2 Master VR1 Backup Virtual Router ID 2 Bridge 1 Bridge Host 1 Host 2 Host 3 Host 4 VR1 master (RouterA( RouterA) ) failure 7. VR1 backup routers (RouterB) master down interval timeout occurs; VR1 master router election process occurs, resulting in RouterB becoming the new VR1 master 8. VR1 master (RouterB) sends advertisement message - SAS in RPR Bridge1 & RPR Bridge2 associates VMAC1 with RouterB MAC (MAC RB ) - Bridge1 forwards VRRP advertisement message to Host1 and Host2 - VR1 master (RouterB) sends advertisement message every Advertisement_Interval (e.g., 1 sec) 9. VR1 master (RouterB) broadcast gratuitous ARP message - SAS in RPR Bridge1 & RPR Bridge2 associates VR master interface MAC with RouterB MAC (MAC RB ) - Bridge1 forwards gratuitous ARP to Host1 and Host2 - Host1 and Host2 updates ARP cache table Marc Holness - 34

35 VRRP/RPR packet walk-thru SAS DB Virtual Router ID 1 Remote MAC VID RPR MAC Router B MAC H1 MAC B1 VR1 Master VR2 Backup VR2 Master VR1 Backup MAC H2 MAC B1 Virtual Router ID 2 Bridge 1 Bridge SAS DB Remote MAC VID RPR MAC Host 1 Host 2 Host 3 Host 4 VMAC MAC RB VRRP process to facilitate master router switchover results in the t SAS data bases to be updated. Marc Holness - 35

36 VRRP/RPR packet walk-thru Virtual Router ID 1 Router B VR1 Master VR2 Backup VR2 Master VR1 Backup Virtual Router ID 2 Bridge 1 Bridge Host 1 Host 2 Host 3 Host 4 Normal operation 10. Host1 sends message to off-net Host via VR1 (using VMAC in destination address) - RPR Bridge1 MAC indexes SAS DB using VMAC and discovers RPR MAC address MAC RB is RPR destination target address to perform directed transmission to RPR station RouterB 11. Off-net Host messages Host1 via VR1 master (RouterB) - RPR RouterB MAC indexes SAS DB using MAC H1 and discovers RPR MAC address MAC B1 is RPR destination target address to perform directed transmission to RPR station Bridge1 - Bridge1 dispatches packet to Host1 SAS continues to provide spatial reuse over RPR involving VRRP interactions. i Marc Holness - 36