You can make router as tftp server but for this u should check the running config on router to check if you are using or not.
Do a netstat then a 3 for connections, F14 to sort by local port and find your TFTP port. The listener will have an *. If there are incoming TFTP sessions you might seem there if you are reviewing it often.
That said, we turned this off for PCI(it’s a vulnerability) with no adverse effects to any system or incoming processes. We are a large shop with communications to many different types of systems and platforms. If this is for PCI, FYI we also turned off Network Station Manager and the Logon Daemon, NFS, LDAP and REXex. No one ever figured out why they were autostarted in the first place.