IP spoofing
IP spoofing is the creation of IP packets using somebody else's IP address as the source address of an IP packet.
Let's take a look at IP headers in an IP packet:
In the following diagram, the attackers represent someone else's IP address:
Anti-spoofing using access lists
A network operator can implement an anti-spoofing access-list filter to prevent packets with incorrect source IP addresses from entering and leaving the network. With the following command, the access list will prevent incoming packets that have the internal IP address from coming in. 220.x.x.x is a network which I own, so I do not expect to encounter any packets coming from outside my own IP address.
Cisco IOS command:
access-list 101 deny 220.x.x.0 0.0.0.255 anyEncryption
Another possible way to prevent IP spoofing is to encrypt all network traffic to prevent source and destination hosts from being compromised.
Anti-spoofing using RPF checks
RPF is a feature with multi vendor support to prevent IP spoofing. It can...
