Fspf Routes - HP 5920 series Configuration Manual

However, the static routes cannot automatically adapt to network topology changes. When the network
fails or the network topology changes, the routes might fail to be reachable, and the network is
interrupted. In this case, you must manually modify the static routes.
Static routes support equal-cost routes. When you configure multiple equal-cost static routes to the same
destination but with different outgoing interfaces, equal-cost routes are generated.

FSPF routes

As a route selection protocol based on link states, FSPF can automatically calculate the best path
between any two switches in a fabric.
FSPF has the following characteristics:
Can be used for any topology.
•
Supports equal-cost routes.
•
Performs topology calculations on a per-VSAN basis.
•
• Runs only on E_Ports and provides a loop-free topology.
Provides a topology database on each switch to track the state of all links.
•
Uses the Dijkstra algorithm to calculate routes.
•
Provides fast convergence in the event of topology changes.
•
Basic concepts
LSDB
•
The link state database (LSDB) is used to store global topology information for switches and link
state information of all switches in link state records (LSRs).
LSR
•
An LSR describes information about all link states between a switch and its directly connected
switches.
Each LSR generated by a switch is called an LSR instance. LSRs generated by all switches comprise
the LSDB. An LSR contains one or more pieces of link state information, including the following:
LSR hold time.
Domain ID of the switch advertising the LSR.
LSR instance number. Every time an LSR is updated, the instance number increments by 1.
Link ID, which identifies a link and includes the domain ID of the switch at the peer end of the
link.
Source interface and destination interface of the link.
Link type, for example, point-to-point connection.
Cost for packet transmission over the link. Each link has a different cost. The smaller the cost,
the better the link. The route selection algorithm uses this value to determine the best route. The
interface cost is configurable.
FSPF packet types
The following protocol packets are used in FSPF:
Hello packets—Sent periodically to discover and maintain FSPF neighbors.
•
Link state update (LSU)—Advertises local link state information in LSRs to the neighboring switches.
•
• Link state acknowledgment (LSA)—Acknowledges the received LSR.
40