3com 8807 User Guide

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Configuring OSPF
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The AuthLen field refers to the length of CA_TLV, and the length of CA_TLV is 20;
The Sequence number and AuthData fields are determined by the OSPF check 
information.
LLS data can be included in only HELLO packets and DD packets. Only one LLS 
data can be included in a packet. EO_TLV must be included in LLS data. 
Additionally, CA_TLV must be included in LLS data is OSPF is configured with MD5 
check.
Format of DD Packets of Extended OOB
The R_bit set in a DD packet indicates that this is an OOB process.
Figure 81   Format of DD Packets of the R-bit set
OSPF GR Features 
Supported by Comware
The two GR methods above are supported in the implementation of Comware.
Configuring OSPF
OSPF configuration needs cooperation among routers: intra-area, area boundary, 
and AS boundary. If none of OSPF parameters is configured, their default settings 
apply. In this case, sent and received packets are not authenticated, and an 
individual interface does not belong to the area of any AS. When reconfiguring a 
default parameter on one router, make sure that the same change is made on all 
other involved routers.
In various configurations, you must first enable OSPF, specify the interface and 
area ID before configuring other functions. But the configuration of the functions 
related to the interface is not restricted by whether the OSPF is enabled or not. It 
should be noted that after OSPF is disabled, the OSPF-related interface parameters 
also become invalid.