When finishing upgrade 2 NE40Es, customer find that the service between Nortel BSC and Nortel BTS is interrupted and the service Between Huawei BSC and Huawei BTS is ok; but before we upgrade the second one, both the services are ok. From NE40E to Nortel BTS, PING does work, but from Nortel BSC to Nortel BTS, there are dropped packets sometimes.
The topo is attached.
1, Because we must change the configuration files which are over 10,000 rows after upgrade(the old configuration files are incorrect and some commands are hidden in the new version) , firstly we check the configuration again but find nothing.
2, Because when finishing the first NE40E the service is ok, we compare the 2 configurations and find that some "global-mp-group" interface number are not same(R&D suggest they are same). But, after changing it, the problem also exists.
3, Check the OSPF peer between NE40E and Nortel routers and then find that the OSPF router ID on both NE40Es are same. Config the 2 router id, then the service is ok.
Normally, in one network there is not any interface whose IP address is the same as other interfaces; so Router IDs are not same when routers select one of its interface IPs as its Router ID.
But, when deploy E-APS which requires the same IP address on different 2 Routers, the Router IDs on the 2 Routers are same when they select "global-mp-group" interface IP address.
Manually config the Router ID.