Reference Guide
660 | Open Shortest Path First (OSPFv2)
www.dell.com | support.dell.com
Figure 35-3. Priority and Costs Example
Implementing OSPF with Dell Networking OS
Dell Networking OS supports up to 10,000 OSPF routes. Within that 10,000 up to 8,000 routes can be
designated as external and up to 2,000 designated as inter/intra area routes.
The S5000 supports up to 16 processes simultaneously.
Dell Networking OS supports Stub areas, Totally Stub (No Summary) and Not So Stubby Areas (NSSAs)
and supports the following LSAs, as discussed earlier in this document.
• Router (type 1)
• Network (type 2)
• Network Summary (type 3)
• AS Boundary (type 4)
• AS External (type 5)
• NSSA External (type 7)
• Opaque Link-local (type 9)
Router 1
Priority 200
Cost 21
Router 2
Priority 180
Cost 50
Router 3
Priority 100
Cost 25
Router 4
Priority 150
Cost 20
Router 1 selected by the system as DR.
Router 2 selected by the system as BDR.
If R1 fails, the system subtracts 21 from R1s priority
number. R1s new priority is 179.
R2 as both the selected BDR and the now-highest
priority, becomes the DR.
If R3 fails, the system subtracts 50 from its priority.
R2s new priority is 130.
R4 is now the highest priority and becomes the DR.