Table of Contents
Understand and implement dynamic ARP testing
Dynamic ARP Inspection (DAI) prevents Address Change Protocol (ARP) packets (Yagra RP Poison and ARP Memory Poison) from being intercepted.
DAI examines ARP from the local network to detect all ARP packets and prevent ARP errors, storing the information in the DHCP trace database. The values of ARP requests and responses are compared to entries in the DHCP access database, and filtering decisions are made based on the results of these comparisons. If the MAC or IP address in the ARP packet does not match a valid entry in the DHCP registry, the packet is lost.
Spoofing and ARP detection
ARP packets are sent to network routing devices to increase network speed and prevent CPU overload.
Addressing protocol
After breaking the ARP
• RP for internal audit
• Enter the values of the scan package
Addressing protocol
To send IP packets over a multicast network, the IP address must be converted to an Ethernet MAC address.
ARP is used to map MAC addresses to IP addresses on an Ethernet LAN.
Each device on the network must send a network packet to move the stored route map. If another device does not have an entry in the ARP cache, the owner (DHCP client) sends an ARP request to that device’s address and prints a response.
ARP penalty
Man-in-the-middle attacks are possible through RP spoofing. Hosts send ARP packets to check the MAC addresses of other devices on your local network. Direct traffic to the device instead of the original network device. If the attacker is a replicating machine, he attacks the OH key and redirects all traffic to the other attacker’s machine. A cell redirects traffic and prevents it from reaching its destination.
Unsolicited ARP, also known as ARP spoofing, occurs when a device on your network sends an authentic ARP request to its own IP address. In normal LAN operation, all ARP messages point to the two MAC addresses of the Go device. It updates the network ARP cache for other local network devices when the device’s network adapter changes when the device restarts. In the worst case scenario, an attacker can hijack the network’s ARP cache and send the device’s ARP response to a specific MAC address instead of including all packets for that IP address.
DAI inspects ARP responses to prevent MAC spoofing and other RP eavesdropping.
Dynamic ARP inspection
DAI examines all RP requests and responses on the local network and examines all ARP packets. The relay accepts all ARP packets and checks the DHCP registry. If the IP-MAC record in the database does not match the information in the ARP packet, the DAI can drop the ARP packet and update the ARP cache with the information in the OH packet. If the packet contains an invalid IP address, the DAI returns an ARP packet. ARP request packets sent by any switch are not subject to ARP inspection.
On X-series and QFXDY-series switches, Junos OS accepts ARP packets on all access ports because these ports are untrusted. By default, DAI allows ARP packets to pass through the router based on the trunk port.
DAI can be configured per interface (port) or per VLAN. By default, DAI is disabled on all VLANs.
If RAW is configured to trust an interface with a DHCP gateway, all ARP destination packets are trusted.
When an ARP request is sent on any VLAN, the packet is sent to all OH switches connected to the network device. ARP response control keys for DAI EH requests.
The packet forwarding process handles all ARP packets. The routing engine blocks ARP packets to avoid overloading the CPU.
If the DHCP server is down or the IP-MAC entry in the ARP packet is omitted, the packet is dropped.
Special access packages
Rowan class function (CF) directories and lines
