Short Version: Can the MX250 operate at 100mb/half-duplex with a copper SFP in the WAN port?   Long Version: We ran into an issue recently installing a new MX250. We overlooked that the dedicated WAN ports are SFP only in this model, and as such did not have a Meraki SFP handy. We ordered one, but to get it working in the meantime we used a Cisco GLC-TE SFP. I've never had an issue using these with Meraki devices in the past, but we were unable to even get a link light using this.   I turned out the problem was the SFP would not auto-negotiate to 100Mb (The MX is plugged directly into the ISP, and through tests with another switch we observed the ISP router is 100Mb/half-duplex). The setting could not be changed to less than 1Gb in the hardware.   In order to actually make it work we were forced to insert a switch in between the MX and the ISP to basically act like a glorified media converter (still using the cisco SFP in the meraki). This switch cannot stay, and we hope to remove it when we get the Meraki SFP.   I will not be back at the remote branch where this was installed for some weeks, and I have some concerns about the MA-SFP-1GB-TX that we ordered. In the specs it lists it's operating speed as 1Gbps, where Cisco's GLC-TE actually lists it's speeds as 10/100/1000. I am worried that the problem is not with the SFP, but with the MX250 itself not being able to set it's WAN ports to less than 1Gbps. If this is the case we are hosed.   Can anyone confirm this?   Thank you ... View more