I deployed a Cisco 4331 router as our firewall and turned on login failure and success logging in the config and noticed the router is getting hammered by login failure on telnet port 23. Port 23 is blocked and logins are blocked after so many failed attempts but what concerns is the volume of attempts. My syslog server shows thousands of attempts from multiple IP's from all over the globe in a 24 hour time frame. Does anyone else have this problem? Is this common? To be honest it really kind of freaks me out and I could use some advice as to what to do about it. Below is is just a fragment of what is being logged.