An easy way to determine legitimacy of an unexpected email is to reply (without opening the inbound message) and ask the sender whether they intended to send you the message and/or attachment.
CISCO
Since 1983, we have sold many brands of network infrastructure equipment. No one has as broad a product line as CISCO. Their SMB equipment offerings are just as reliable and feature-rich as their data center product line. We extensively use their routers, switches, VPN, and wireless devices.