Migrate from VRRP to DvR

About this task

If you have a VRRP network with a mix of existing routers that do not support DvR and devices that do support DvR, you can migrate your VRRP network to DvR using this high-level process. This migration process assumes the following design:

  • Existing routers are the VRRP masters.

  • Existing routers are the default gateways for all subnets.

  • Fabric Connect network with DvR-capable nodes where DvR is configured globally, but not on I-SIDs, on the VOSS devices; and VOSS devices operate in Layer 2 mode for the VRRP VLANs that need to be migrated.

Important

Important

When you configure DvR on Controllers with existing VRRP VLANs, ensure there is no VRRP VLAN with VRID 37 or VRID 38. VRID 37 conflicts with the DvR gateway MAC used by all DvR nodes. The DvR gateway MAC is a constant value 00:00:5e:00:01:25; VRRP VRID 37 translates to the same MAC. Similarly, VRRP VRID 38 translates to 00:00:5e:00:01:26, and is used within DvR. If you have a VRRP VLAN with either of these VRIDs, change the VRID to a different value.

Procedure

  1. Enable VRRP interfaces on the DvR Controllers but keep VRRP mastership on the existing routers.
  2. Change VRRP mastership on the VLAN or IP Subnet in question on the DvR Controller by applying a higher priority than the current master.
    Note

    Note

    You can easily fall back to the original VRRP master to change VRRP priorities back.

  3. Disable VRRP on the existing routers.
  4. Subnet by subnet (VLAN/I-SID), delete VRRP interfaces on all DvR Controllers first (this includes removing VRRP and removing the VLAN IP address), and then configure DvR interfaces (this includes adding the DVR-GW-IP, enabling DvR, and then adding the VLAN IP address) on the VLAN/I-SID instead. This might lead to a short traffic interruption.
    Note

    Note

    For each VLAN/I-SID, ensure that VRRP is disabled on all nodes before you configure DvR interfaces on the Controllers for the VLAN/I-SID.

    Keep in mind that you can only enable DvR on VLAN or I-SIDs where all participating BEBs are DvR-capable.

    Anytime when falling back, you can delete the DvR interface on the I-SID (this includes disabling DvR, removing the DVR-GW-IP and removing the VLAN IP address) and configure the VRRP interface again (this includes adding the VLAN IP address and adding VRRP again), however, ensure you delete the DvR interfaces on all Controllers first before you enable VRRP again.

Example

Start with VRRP VLAN:

vlan create 250 name vlan_test250 type port-mstprstp 0
vlan i-sid 250 111250
interface vlan 250
ip address 192.0.2.3 255.255.255.0
interface vlan 250
ip vrrp version 2
ip vrrp address 10 192.0.2.1
ip vrrp 10 priority 180
ip vrrp 10 backup-master enable
ip vrrp 10 enable
exit

Change to DvR VLAN:

interface vlan 250
no ip vrrp address 10 192.0.2.1
no ip address 192.0.2.3
exit
interface vlan 250
dvr gw-ipv4 192.0.2.1
dvr enable
ip address 192.0.2.3 255.255.255.0
exit

Change back to VRRP VLAN:

interface vlan 250
no dvr enable
no dvr gw-ipv4
no ip address 192.0.2.3
exit
interface vlan 250
ip address 192.0.2.3 255.255.255.0
ip vrrp version 2
ip vrrp address 10 192.0.2.1
ip vrrp 10 priority 180
ip vrrp 10 backup-master enable
ip vrrp 10 enable
exit
9039040-00 Rev AB