Published on January 21, 2005

Protect your router from a dictionary DoS attack

You may not realize it, but a dictionary denial of service (DoS) attack on Telnet, SSH, or HTTP ports could hit your Cisco router.

By David Davis, TechRepublic

Of course, having these ports open to a public network is much more dangerous than leaving them open on a private network.

But either way, you need to do whatever you can to protect your routers from a dictionary DoS attack, which attackers could use to gain access to your router or simply create a service outage on your network.

Thanks to login enhancements in IOS 12.3(4)T and later, you can provide your routers with additional protection. These new login enhancements offer the following benefits:

Create delays between successive login attempts.

Disallow login if there are too many failed login attempts.

Create messages in the system log or send SNMP traps that alert/record additional information about the failed and disallowed logins.

Click here to Read the Full Article