9. Prevent router attacks

Now that we know that our routers are prone to attacks, how should we defend against them? The following suggestions are provided:
 
1. Update the vro operating system in a timely manner: like the network operating system, the vro operating system also needs to be updated to correct programming errors, software flaws, and cache overflow problems. Always query the current update and operating system version from your vro manufacturer.
 
2. Modify the default password: According to the Computer Emergency Response Team of Carnegie Mellon University, 80% of security events are caused by weak or default passwords. Avoid using common passwords, and use a mix of uppercase and lowercase letters as stronger password rules.
 
3. Disable HTTP settings and SNMP (Simple Network Management Protocol): the HTTP settings of your vro are easy for a busy network administrator. However, this is also a security problem for vrouters. If your vro has a command line setting, disable HTTP and use this setting method. If you are not using SNMP on your vro, you do not need to enable this function. A Cisco router has an SNMP security vulnerability that is vulnerable to GRE tunnel attacks.
 
4. Blocking ICMP (Internet Control Message Protocol) ping requests: ping and other ICMP functions are very useful tools for network administrators and hackers. Hackers can use the ICMP feature enabled on your vro to find information that can be used to attack your network.
 
5. Disable telnet commands from the Internet: In most cases, you do not need active telnet sessions from Internet interfaces. If you access your vro from the inside, the configuration will be safer.
 
6. Disable IP-targeted broadcast: IP-targeted broadcast allows you to launch denial-of-service attacks on your devices. The memory and CPU of A vro cannot withstand too many requests. This result may cause cache overflow.
 
7. Disable IP routing and IP redirection: retargeting allows data packets to come in from one interface and then exit from another interface. You do not need to redirect specially designed data packets to a dedicated internal network.
 
8. packet filtering: packet filtering only transmits the data packets that you are allowed to access your network. Many companies only allow port 80 (HTTP) and Port 110/25 (email ). In addition, you can block and allow IP addresses and ranges.
 
9. disable unnecessary services: disable unnecessary services on routers, servers, and workstations. Cisco devices provide small services by default through network operating systems, such as echo, chargen and discard ). These services, especially their UDP services, are rarely used for legal purposes. However, these services can be used to launch denial-of-service attacks and other attacks. Packet filtering can prevent these attacks.