I have 2 hp c-Class enclosures..each have 2 cisco 3020s...so 4 total. these 4 switches connect back to 2 6513s. I am trunking between the 3020s and 6513s...however I am seeing something weird. On the 3020s, I am seeing the interfaces as up and on the 6513s I am seeing the interfaces as down. All my uplinks are fiber. The 6513s are running UDLD Aggressive. I've experimented with aggressive, non-agressive and disabled on the 3020s and have had no luck getting any link on the 6513s. I have confirmed the configurations on both both sides are exactly the same. They are also configured in channel-groups. But I have tried remving the channel-groups from the interfaces and they still did not come up on the 6513 side. Anybody ever run into a problem like this or have any suggestions on what I could try to resolve the issue?