2621 Router to 3512XL Switch Using Fiber

[tdunlap]

Are there any pitfalls to avoid connecting the two devices with fiber? I have a 100BASET conenction from the 2621 connected to a Media Concerter (100BASET to FL) this is a Transition Network SSETF1013-200. I have installed a WS-G5484 GBIC module in the 3512. I can get the links to function too some degree but can't get it to lock on 100MB uplink from the 2621. Is this a software issue?

[badamson]

You aren't going to get a connection from a 100Mbps interface to a 1Gbps interface. There are a handful of companies that have developed a 100Meg to 1Gb media converter. The ones I have seen are priced between $500 and $1000.