Is it possible to change the frequency that a CISCO router sends a DHCP discover packet? Or is there a way to poke it and make it request one?
why on earth would you have a router using DHCP for addressing?
the frequency will depend on the lease its already obtained from the DHCP server.
powercycling should also force it to recheck, as will configuring the interface statically and then switching back to DHCP.
Not sure about the dhcp discover, but you can set the lease time on the dhcp client :
It should at lease send a dhcp renew when the lease expires.
To force a renew :