Oracle Grid manager does not see database instances?!

I have two lan's seperated by a router.
On lan1 i am running oracle EM-grid control. On lan2 there are several
oracle databases (all using the grid-agent) The problem is that i see all targets in grid control (agents, listener and database instances)
Agents and listenrs are NO problem, but when i try to view in grid control the database instance i always get the error: "Io exception: The Network Adapter could not establish the connection"
or more detailed:

2007-07-20 12:31:25,203 [MetricCollector:HOMETAB_THREAD600:60] ERROR rt.DbMetricCollectorTarget _getAllData.326 - oracle.sysman.emSDK.emd.comm.CommException: cis_amst2 oracle.sysman.emSDK.emd.comm.CommException: cis_amst2

        at
oracle.sysman.emSDK.emd.comm.EMDClient.getResponseForRequest(EMDClient.java­: 1543)

        at
oracle.sysman.emSDK.emd.comm.EMDClient.getMetrics(EMDClient.java: 915)

        at
oracle.sysman.emo.perf.metric.rt.DbHomeTab._getAllData(DbHomeTab.java: 322)

        at
oracle.sysman.emo.perf.metric.rt.DbHomeTab.getData(DbHomeTab.java: 143)

        at
oracle.sysman.emo.perf.metric.eng.MetricCached.collectCachedData(MetricCach­ ed.java:
404)

        at
oracle.sysman.emo.perf.metric.eng.MetricCollectorThread._collectCachedData(­ MetricCollectorThread.java:
596)

        at
oracle.sysman.emo.perf.metric.eng.MetricCollectorThread.run(MetricCollector­ Thread.java:
320)

        at java.lang.Thread.run(Thread.java:534)

I Think is has something to do whith the router (blocking a port which
is needed for the action) But i do not know which port to open. Can someone help?

Regards,
Anneke Received on Sun Jul 22 2007 - 23:38:11 CDT