Administrator Guide

• The remote VTEP should already be configured.
• In case of static VXLAN VLT deployments, this configuration should be symmetric across VLT nodes.
• Disable MAC address learning on static VXLAN tunnels.
VXLAN-INSTANCE mode
disable-mac-learning remote-vtep-ip
DellEMC(conf-vxlan-inst-1-static)#disable-mac-learning 24.1.1.0
• Enable MAC address learning on static VXLAN tunnels.
VXLAN-INSTANCE mode
no disable-mac-learning remote-vtep-ip
DellEMC(conf-vxlan-inst-1-static)#no disable-mac-learning 24.1.1.0
Preserving 802.1 p value across VXLAN tunnels
The 802.1p QoS marking preservation is supported over the VXLAN tunnel. The 802.1p priority is carried over from the VXLAN tunnel to
the remote VTEP—VXLAN tunnel endpoint. The packets egress out to the correct queue based on the priority value. In such a scenario, if
there is any congestion in the queue, the system generates a pause. The network port should be a vlan for priority to be carried by the
vxlan outer header.
VXLAN Scenario
VXLAN tunnel stays down even if the remote VTEP IP is reachable through a recursive route. Following section explains the scenario
through an example configuration.
The following illustration depicts the topology in which the VTEPs are connected.
Figure 167. VXLAN Scenario
In the above illustration, R1 and R2 are the VTEPs that are trying to form the VXLAN tunnel. R3, the route reflector, exchanges the routes
across two IBGP peers (R1 and R2). Also, the R3 connects the R1 and R2 through a default route.
Following is the output of show ip routecommand for the above connection:
DellEMC# show ip route
Destination Gateway Dist/Metric Last Change
----------- ----- ----------- -----------
*B IN 0.0.0.0/0 via 192.168.11.2 200/0 16:13:30
C 1.1.1.1/32 Direct, Lo 1 0/0 8:59:34
B IN 2.2.2.2/32 via 192.168.22.1 200/0 00:36:48
From the above routing table it is understood that the remote VTEP 2.2.2.2/32 is resolved through next-hop 192.168.22.1, which is not
directly connected. This route is considered as a recursive route and there is no other route matching the next-hop except the default
0.0.0.0/0. If the recursive lookup ends in a default route, the route is considered to be an unsuccessful recursion. The VXLAN tunnel stays
down even though the remote VTEP IP is reachable through a recursive route. As a workaround, make sure to advertise the underlying
routes from the route-reflector, so that the recursive lookup succeeds.
1012
Virtual Extensible LAN (VXLAN)