I m trying to connect two routers via STM media with pos interface ,but status shows POS up/line interface down .I have checked the media end to end (loop & break ) tested ok .Still line protocol is down & we cant ping to other router .How to resolve or trouble shoot this .Please guide
It could be an issue of encapsulation mismatch (e.g. one side uses PPP and the other HDLC). Sometimes there could be issues with the "pos flag s1s0" command (value 0 for SONET, 2 for SDH). Please inform us about the router models and the type of the port adapters/linecards you are using at each side of the link. Posting the pos interface configurations and output from "show controller pos x/y detail" would also help to explore this further.