You can manually configure the OSPF link type for a VLAN. OSPF Link Types describes the link types.
|Link Type||Number of Routers||Description|
|Auto||Varies||ExtremeXOS automatically determines the OSPF link type based on the interface type. This is the default setting.|
|Broadcast||Any||Routers must elect a designated router (DR) and a backup designated router (BDR) during synchronization. Ethernet is an example of a broadcast link.|
|Point-to-point||Up to 2||This type synchronizes faster than a broadcast link because routers do not elect a DR or BDR. It does not operate with more than two routers on the same VLAN. The Point-to-Point Protocol (PPP) is an example of a point-to-point link. An OSPF point-to-point link supports only zero to two OSPF routers and does not elect a designated router (DR) or backup designated router (BDR). If you have three or more routers on the VLAN, OSPF fails to synchronize if the neighbor is not configured.|
|Passive||A passive link does not send or receive OSPF packets.|
The number of routers in an OSPF point-to-point link is determined per VLAN, not per link.
All routers in the VLAN must have the same OSPF link type. If there is a mismatch, OSPF attempts to operate, but it may not be reliable.