Multihoming an IP-Connected End System Design and Implementation
For an overview of multihoming an IP-connected end system, see the Multihoming Support for IP-Connected End Systems section in Data Center Fabric Blueprint Architecture Components.
Figure 1 illustrates the multihomed IP-connected end system—in this procedure, the end system is an IP-connected server—that is enabled using this procedure:
This configuration uses one VLAN per leaf device access interface. See Configuring a Layer 3 Subinterface (CLI Procedure) to enable VLAN tagging if your setup requires multiple VLANs per leaf device access interface.
Configuring the End System-Facing Interfaces on a Leaf Device
To configure the IP address of each end system-facing interface on the leaf devices:
- Configure an IP address on each end system-facing leaf
device interface, and put the interface in a VRF.
set interfaces et-0/0/15 unit 0 family inet address 172.16.104.1/30 set routing-instances VRF_5 interface et-0/0/15.0
The VRF_5 routing instance was configured earlier in this guide with this EBGP configuration. See Routed Overlay Design and Implementation.
set interfaces et-0/0/15 unit 0 family inet address 172.16.104.5/30 set routing-instances VRF_5 interface et-0/0/15.0
set interfaces et-0/0/15 unit 0 family inet address 172.16.104.9/30 set routing-instances VRF_5 interface et-0/0/15.0
The VRF_5 routing instance was not explicitly configured for Leaf 11 and 12 earlier in this guide.
To configure the VRF_5 routing instance to run on Leaf 11 and 12, repeat the procedures in Routed Overlay Design and Implementation for these leaf devices. Be sure to configure a unique route distinguisher for each route to ensure that each leaf device route is treated as a unique route by the route reflectors.
- After committing the configuration, confirm that each
link is up and that the IP address is properly assigned.
Sample output from Leaf 10 only is provided in this step.
user@leaf10> show interfaces terse et-0/0/15 Interface Admin Link Proto Local Remote et-0/0/15 up up et-0/0/15.0 up up inet 172.16.104.1/30
Configuring EBGP Between the Leaf Device and the IP-Connected End System
EBGP—which is already used in this reference design to pass routes between spine and leaf devices in the underlay network—is also used in this reference design to pass routes between the IP-connected server and a leaf device.
Other routing protocols can be used to pass routes between an IP-connected end system and the leaf device. However this is not recommended.
To configure EBGP between a leaf device and an IP-connected end system:
- Configure EBGP in a VRF routing instance.
set routing-instances VRF_5 protocols bgp group END_SYSTEM_1 type external set routing-instances VRF_5 protocols bgp group END_SYSTEM_1 neighbor 172.16.104.2 peer-as 4220000001
- Repeat this procedure on all leaf device interfaces that
are multihomed to the IP-connected end system.
set routing-instances VRF_5 protocols bgp group END_SYSTEM_1 type external set routing-instances VRF_5 protocols bgp group END_SYSTEM_1 neighbor 172.16.104.6 peer-as 4220000001
set routing-instances VRF_5 protocols bgp group END_SYSTEM_1 type external set routing-instances VRF_5 protocols bgp group END_SYSTEM_1 neighbor 172.16.104.10 peer-as 4220000001
- After committing the configurations, confirm that BGP
A sample of this verification procedure on Leaf 10 is provided below.
user@leaf10> show bgp summary instance VRF_5 Groups: 1 Peers: 2 Down peers: 0 Table Tot Paths Act Paths Suppressed History Damp State Pending VRF_5.inet.0 1 1 0 0 0 0 VRF_5.mdt.0 0 0 0 0 0 0 VRF_5.evpn.0 32 8 0 0 0 0 Peer AS InPkt OutPkt OutQ Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped... 172.16.104.2 422000001 28 24 0 1 10:37 Establ VRF_5.inet.0: 1/1/1/0
Multihoming an IP-Connected End System—Release History
Table 1 provides a history of all of the features in this section and their support within this reference design.
Table 1: Multihoming IP-Connected End Systems Release History
QFX10002-60C and QFX5120-32C switches running Junos OS Release 19.1R2 and later releases in the same release train support all features documented in this section.
All devices in the reference design that support Junos OS Release 17.3R3-S1 and later releases in the same release train also support all features documented in this section.