3com 8807 User Guide

Symptom 2: BGP route cannot be advertised correctly after route of IGP is 
imported with the network command.

Solution: Route imported by the network command should be same as a route 
in the current routing table, which should include destination segment and mask. 
Route covering large network segment cannot be imported. For example, route 
10.1.1.0/24 can be imported, while 10.0.0.0/8 may cause error. If Ospf is used, 
after a large network segment is imported to the local route by means of the 
network command, the router will automatically make changes according to the 
network segment actually used by the interface. Consequently, the network 
command will fail to, or incorrectly, import routes, which can cause routing errors 
when some network faults exist.