API Guide

OS10 Switch Overlay next-
hop entries
Underlay next-
hop entries
Overlay L3 RIF
entries
Underlay L3 RIF entries
S52xx-ON series:
default-overlay-routing
disable-overlay-routing
balanced-overlay-routing
scaled-overlay-routing
—
8192
0
32768
53248
—
57344
65536
32768
12288
—
2048
0
8192
12288
—
14336
16384
8192
4096
S4248-ON:
default-overlay-routing
—
20480
—
110592
—
4096
—
28672
NOTE: The S4248-ON switch supports only one default profile to reserve resources for overlay ARP entries.
To activate the profile after you configure an overlay routing profile, save the configuration and reload the switch.
Configure an overlay routing profile
• Enable an overlay routing profile in Configuration mode or disable the configured profile and return to the default.
OS10(config)# hardware overlay-routing-profile {disable-overlay-routing | balanced-overlay-
routing |
scaled-overlay-routing}
Display overlay routing profiles
• View the hardware resources available for overlay routing in different profiles; for example, in the S5200-ON series:
OS10# show hardware overlay-routing-profile mode all
Mode Overlay Next-hop Underlay Next-hop Overlay L3 RIF Underlay L3
RIF
Entries Entries Entries Entries
default-overlay-routing 8192 57344 2048
14336
disable-overlay-routing 0 65536 0
16384
balanced-overlay-routing 32768 32768 8192
8192
scaled-overlay-routing 53248 12288 12288 4096
• View the currently configured overlay routing profile; for example, in the S5200-ON series:
show hardware overlay-routing-profile mode
Overlay Underlay Overlay Underlay
Setting Mode Next-hop Next-hop L3 RIF L3 RIF
Entries Entries Entries Entries
Current default-overlay-routing 8192 57344 2048 14336
Next-boot default-overlay-routing 8192 57344 2048 14336
DHCP relay on VTEPs
Dynamic Host Configuration Protocol (DHCP) clients on hosts in the overlay communicate with a DHCP server using a DHCP relay on the
VTEP switch. To work seamlessly, VTEP DHCP relay transmits the virtual-network IP address of the relay interface to the DHCP server.
By default, DHCP uses the giaddr packet field to carry these addresses to the server. In a VxLAN, which has overlay and underlay
subnets in the same default VRF, DHCP relay on VTEPs operates without user intervention. However, in a VXLAN in which the underlay
and overlay are in different VRFs, the default DHCP method is not successful. The IP tenant subnet is in the overlay address space. The IP
address where the VTEP is reachable is in the underlay address space. To transmit the IP subnet of the client separately from the IP
address where the VTEP is reachable, you must configure an additional DHCP sub-option (5 or 151) in DHCP relay agent option 82.
Because OS10 does not support the required sub-options in DHCP relay agent option 82, the giaddr packet field must contain the
virtual-network IP address of the relay interface, and this IP address must be reachable from the DHCP server in the underlay. Each VTEP
that acts as a DHCP relay must have its virtual-network IP address installed using a route leaking mechanism as a route to the underlay
and advertised to all underlay routers, including the spine switches.
VXLAN
15