Open Shortest Path First (OSPF) Exchanging Information for Virtual Extensible LAN (VXLANs)

ExtremeXOS leverages Open Shortest Path First (OSPF) to advertise and learn VTEPs dynamically in a VXLAN network. OSPFv2 advertises the triplet of VNI/Endpoint IP Address/Advertising Router ID through OSPFv2 domain using type 11 opaque link state advertisements (LSAs). The OSPFv2 VXLAN LSA link state ID uses opaque type 128. The remaining 24 bits of the field are set to the VXLAN VNI. Each locally configured VNI corresponds to a single opaque LSA advertised by the router. The OSPFv2 VXLAN LSA payload contains one top level TLV that specifies the locally configured IPv4 endpoint address on the advertising router.


  • The remote endpoints learned using OSPF are not saved to the configuration.
  • The OSPFv2 VXLAN opaque LSA is only advertised if OSPF VXLAN extensions are enabled.
  • OSPF VXLAN extensions can only be enabled when OSPFv2 is disabled.
  • Local endpoint address can only be IPv4. IPv6 is not supported.

Supported Platforms

Summit X770 and X670-G2 series switches (standalone), and stacks that have X770 and X670-G2 slots only.

New CLI Commands

enable ospf vxlan-extensions

disable ospf vxlan-extensions

Changed CLI Commands

The show ospf command output has been changed (shown in bold):

show ospf 

OSPF                : Enabled          MPLS LSP as Next-Hop: No 
RouterId            :   RouterId Selection  : Automatic 
ASBR                : No               ABR                 : No  
ExtLSA              : 0                ExtLSAChecksum      : 0x0    
OriginateNewLSA     : 190              ReceivedNewLSA      : 102        
SpfHoldTime         : 3                Lsa Batch Interval  : 30s 
CapabilityOpaqueLSA : Enabled 
10M Cost            : 10               100M Cost           : 5 
1000M Cost (1G)     : 4                10000M Cost (10G)   : 2 
40000M Cost (40G)   : 2                                         
100000M Cost (100G) : 1                                         
Router Alert        : Disabled         Import Policy File  :  
ASExternal LSALimit : Disabled         Timeout (Count)     : Disabled (0) 
Originate Default   : Disabled 
SNMP Traps          : Disabled 
VXLAN Extensions    : Enabled
Protocol              Status   cost  Type Tag        Policy 
direct                Disabled 0     0    0          None 
static                Disabled 0     0    0          None 
rip                   Disabled 0     0    0          None 
e-bgp                 Disabled 0     0    0          None 
i-bgp                 Disabled 0     0    0          None 
isis-level-1          Disabled 0     0    0          None 
isis-level-2          Disabled 0     0    0          None 
isis-level-1-external Disabled 0     0    0          None 
isis-level-2-external Disabled 0     0    0          None