Setting The Dscp Value For Ospf Packets; Enabling Ospf Ispf; Configuring Ospf Frr - HP MSR2000 series Configuration Manual

Setting the DSCP value for OSPF packets

An IPv4 packet header contains an 8-bit TOS field. As defined in RFC 2474, the first six bits set the
Differentiated Services Code Point (DSCP) value and the last two bits are reserved. Network devices use
the DSCP value as a reference to determine the packet priority for transmission.
You can set the DSCP value for OSPF packets.
To set the DSCP value for OSPF packets:
Step
1. Enter system view.
2. Enable an OSPF
process and enter
OSPF view.
3. Set the DSCP value
for OSPF packets.

Enabling OSPF ISPF

When a network topology is changed, Incremental Shortest Path First (ISPF) allows the system to
recompute only the affected part of the shortest path tree (SPT), instead of the entire SPT.
To enable OSPF ISPF:
Step
1. Enter system view.
2. Enter OSPF view.
3. Enable OSPF ISPF.

Configuring OSPF FRR

When a link fails, the packets on the link are discarded, and a routing loop may occur until OSPF
completes routing convergence based on the new network topology.
You can enable OSPF fast reroute (FRR) to solve this problem.
Figure 37 Network diagram for OSPF FRR
Command
system-view
ospf [ process-id | router-id router-id |
vpn-instance vpn-instance-name ] *
dscp dscp-value
Command
system-view
ospf [ process-id | router-id router-id |
vpn-instance vpn-instance-name ] *
ispf enable
92
Remarks
N/A
By default, OSPF is not enabled.
Optional.
By default, the DSCP value in OSPF
packets is 48.
Remarks
N/A
N/A
Optional.
Disabled by default.