Ospf Configuration; Configuration Task Sequence - Accton Technology ES4710BD User Manual

1） Each OSPF-enabled layer 3 switch maintains a database (LS database) describing the
link-state of the topology structure of the whole autonomous system. Each layer 3 switch
generates a link-state advertisement according to its surrounding network topology
structure (router LSA), and sends the LSA to the other layer 3 switches through link-state
update (LSU) packets. This way, each layer 3 switch receives LSAs from the other layer 3
switches, and all LSAs combined to the link-state database.
2） Since an LSA is a description to the network topology structure around a layer 3 switch,
the LS database is the description to the network topology structure of the whole network.
The layer 3 switches can easily create a weighted vector map according to the LS database.
Obviously, all layer 3 switches in the same autonomous system will have the same network
topology map.
3） Each layer 3 switch uses the shortest path finding (SPF) algorithm to calculate a tree of
shortest path rooted by itself. The tree provides the route to all the nodes in the
autonomous system, leaf nodes consist of the exterior route information. The exterior route
can be marked by the layer 3 switch broadcast it so that additional information about the
autonomous system can be recorded. As a result, the route table of each layer 3 switch is
different.
OSPF protocol was developed by the IETF, and OSPF v2 widely used now is accordance to the
content described in RFC2328.

18.4.2 OSPF Configuration

The OSPF configuration for DSCRS series switches may be different from the configuration
procedure to switches of the other manufacturers. It is a two-step process:
1. Enable OSPF in the Global Mode;
2. Configure OSPF area for the interface.
18.4.2.1

Configuration Task Sequence

1. Enable OSPF (required)
(1) Enable/disable OSPF (required)
(2) Configure the ID number of the layer 3 switch running OSPF (optional)
(3) Configure the network scope for running OSPF (optional)
(4) Configure the area for the interface (required)
2. Configure OSPF sub-parameters (optional)
(1) Configure OSPF packet sending mechanism parameters
a. Configure OSPF packet verification
b. Set the OSPF interface to receive only
c. Configure the cost for sending packets from the interface
d. Configure OSPF packet sending timer parameter (timer of broadcast interface sending
HELLO packet to poll, timer of neighboring layer 3 switch invalid timeout, timer of LSA
transmission delay and timer of LSA retransmission.
(2) Configure OSPF route introduction parameters
a. Configure default parameters (default type, default tag value, default cost, default interval
and default number uplimit)
b. Configure the routes of the other protocols to introduce to OSPF.
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