70 likes | 230 Views
Migration Indicator on VDP Req. Yizhou Li ( liyizhou@huawei.com ) Bob Sultan ( bsultan@huawei.com ) Gu Yingjie ( guyingjie@huawei.com ) Ben Mack-Crane ( tmackcrane@huawei.com ). VSI 123. VSI 456. VSI 123. VM s. VM s. VM t. Problem. Server X. Server X. EVB Bridge A. EVB Bridge A.
E N D
Migration Indicator on VDP Req Yizhou Li (liyizhou@huawei.com) Bob Sultan (bsultan@huawei.com) Gu Yingjie (guyingjie@huawei.com) Ben Mack-Crane (tmackcrane@huawei.com)
VSI 123 VSI 456 VSI 123 VM s VM s VM t Problem Server X Server X EVB Bridge A EVB Bridge A • 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; started vs. Server Y Server Y EVB Bridge B EVB Bridge B migration terminated
NIC NIC 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 won’t resend DHCP request and hence target port won’t listen any DHCPACK. Therefore filter won’t be enabled on target port. 6 migration 6. VM migration. VM VM VM VM vSwitch vSwitch Server Server 5. DHCPACK 1. DHCP request 1 5 4. DHCP Snooping and set up IP/MAC/vid/port filter 7. DHCP Snooping based filter on new port. How? 7 TOR 4 2. DHCP Request 2 DCN Note:DHCP Discover and DHCP Offer exchanges are ignored in picture 3 3. DHCP Ack DHCP Server
snooped address 5.6.7.8 associated with VSI VDP Req MI=0 VSI 123 VM s lease request VDP Rsp lease granted 5.6.7.8 VDP Req MI=1 VDP Rsp lease query lease info 5.6.7.8 snooped address 5.6.7.8 associated with VSI DHCP Snooping Server X EVB Bridge A • 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; DHCP Server Server Y EVB Bridge B
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;
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