Yizhou Li ([e-mail])

1
Migration Indicator on VDP Req

• Yizhou Li (liyizhou_at_huawei.com)
• Bob Sultan (bsultan_at_huawei.com)
• Gu Yingjie (guyingjie_at_huawei.com)
• Ben Mack-Crane (tmackcrane_at_huawei.com)

2
Problem
Server X
Server X
EVB Bridge A
EVB Bridge A
started
vs.
Server Y
Server Y
EVB Bridge B
EVB Bridge B
migration
terminated

• It is useful for the EVB Bridge server-facing
  port to be aware of whether the VDP request
• is associated with a VM that is migrating or
• is associated with a VM that is
  starting/terminating

3
Problems with DHCP snooping enabled on bridge port

• Problems bridge port snoops DHCPACK and binds
  IP/MAC/vid/port to filter the following traffic.
  When VM moves, VM wont resend DHCP request and
  hence target port wont listen any DHCPACK.
  Therefore filter wont be enabled on target port.

6
migration
VM
VM
VM
VM
6. VM migration.
vSwitch
vSwitch
Server
Server
5. DHCPACK
1. DHCP request
1
5
4. DHCP Snooping and set up IP/MAC/vid/port filter
7
7. DHCP Snooping based filter on new port. How?
TOR
4
2. DHCP Request
2
DCN
NoteDHCP Discover and DHCP Offer exchanges are
ignored in picture
3
3. DHCP Ack
DHCP Server
4
DHCP Snooping
Server X
EVB Bridge A
DHCP Server
Server Y
EVB Bridge B

• DHCP snooping is used on edge bridges (EVB
  Bridges) to filter traffic that has not obtained
  an IP address via DHCP lease on the port (VSI)
• When a VM moves, it does not issue another lease
  request resulting in failure of DHCP snooping at
  the target
• Solution is to communicate via VDP that VM (VSI)
  has migrated rather than starting new

5
Proposal
0 VM newly started (i.e., not migrated) 1 VM
migrated

• Use, for example, high-order bit of Reason field
  in VDP Request
• currently, reason field significant only on
  response
• For discussion whether useful to distinguish
  between terminated VM or migrated VM on
  De-associate

6
Backup slides
7
DHCP leasequery (RFC4388)

• Purpose In case of DHCP relay reboots, relay
  sends leasequery to DHCP server to refetch the
  lease information
• May get lease information via ANY one of MAC, IP
  and Client-Identifier