ItsyourIP.com

Tag: denial-of-service

  • Enable/Configure DHCP Snooping in Cisco Catalyst Switches (IOS)

    DHCP snooping is a DHCP security feature that provides security by filtering untrusted DHCP messages and by building and maintaining a DHCP snooping binding table. An untrusted DHCP message is a message that is received from outside the network or firewall causing denial of service attacks.

    The DHCP snooping binding table contains the MAC address, IP address, lease time, binding type, VLAN number, and interface information that corresponds to the local untrusted interfaces of a switch. An untrusted interface is an interface that is configured to receive messages from outside the network or firewall. A trusted interface is an interface that is configured to receive only messages from within the network.

    DHCP snooping can be enabled on the switch per vlan as it can intercept the DHCP messages at the layer2.

    (more…)

  • Disable ICMP Redirects in Windows(2000,XP,2003)

    ICMP redirect is a type 5 ICMP error message sent by a gateway router to a sending host informing of an optimal alternate route to the destination host and to update its routing table with the new host route to the target destination host.

    ICMP Redirects being an inefficient way to update a hosts routing table of an optimal route to a target destination can cause security issues. A malicious hacker with little knowledge about the network can launch a Denail of Service (DoS) attack on a host on the network.

    (more…)