I have connected a Cisco ASR 1002 router via a sub-Int gi0/0/1.1 [has an IP] to a Cisco 3750G switch. vlan id and dot1q taggs are in place under sub-int and port on switch gi1/0/25 (the uplink) is trunk. the switch port is not connecting. the router side has a link and I can ping router's sub-int IP while on router. the switch has IPservices K9 image on it.
i cannot hard code speed and duplex on the gig sw port since its a gig switchport. I have nonegiciation under this switch port.
I am running out if tricks trying to find out what this switch uplink (trunk at switch side but subint at router side) not coming up.
You give us a general description but not much detail to help us identify the issue. A good next step would be to post the output from the switch of the command show interface status. Also please identify which switch port is connected to router.
Thanks for the update. Glad to know that you resolved the issue and that it was bad SFP. If there is a lesson to be learned from this discussion it is the reminder that even though our first reaction to a problem is to look for configuration issues, that sometimes the problem is in the hardware.