Configuration Guide
Dynamic ARP Inspection Configuration
With this model, device C will cause the corresponding relationship of ARP
entries in device A and device B incorrect. The policy is to broadcast ARP
response to the network continuously. The IP address in this response is
IPA/IPB, and the MAC address is MACC. Then, ARP entries (IPB and MACC)
will exist in device A, and ARP entries (IPA and MACC) exist in device B.
Communication between device A and device B is changed to communication
with device C, which is unknown to devices A and B. Device C acts as an
intermediary and it just modifies the received packets appropriately and
forwards to another device. This is the well-known man in the middle attack.
DAI and ARP Spoofing Attacks
DAI ensures that only legal ARP packets are forwarded by the device. It mainly
performs the following operations:
Intercept all the ARP request and response packets at the untrusted port
that corresponds to VLAN with the DAI inspection function enabled.
Check the validity of the intercepted ARP packets according to the setting
of DHCP database before further processing.
Release the packets that do not pass the inspection.
Appropriately process the packets that pass the inspection and send them
to the destinations.
According to the DHCP snooping binding database, whether ARP packets is
valid or not can be checked . For details, refer to
DHCP Snooping
Configuration
.
Interface Trust Status and Network Security
ARP packets are checked according to the trust status of each port on the
device. DAI check is ignored for the packets that are received through trust
ports and are considered as legal ARP packets. DAI check will be performed
strictly for the ARP packets that are received through untrusted ports.
In a typical network configuration, layer 2 port connected to the network device
should be set as a trust port, and layer 2 port connected to the host device
should be set as an untrusted port.
Note
Incorrectly configuring a layer 2 port as an untrusted port may affect normal
communication of the network.
For specific configuration commands, refer to
ip arp inspection trust, show ip
arp inspection interface.
Summary of Contents for RG-S2900G-E Series
Page 1: ...RG S2900G E Series Switch RGOS Configuration Guide Release 10 4 2b12 p1 ...
Page 91: ...Configuration Guide Configuring PoE Configuration ...
Page 133: ...Configuration Guide EEE Configuration ...
Page 319: ...Configuration Guide QinQ Configuration ...
Page 408: ......
Page 409: ...IP Routing Configuration 1 Static Route Configuration ...
Page 412: ......
Page 413: ...Multicast Configuration 1 IGMP Snooping Configuration 2 MLD Snooping Configuration ...
Page 757: ......
Page 758: ...ACL QoS Configuration 1 Access Control List Configuration 2 QoS Configuration ...
Page 801: ...Reliability Configuration 1 RLDP Configuration 2 TPP Configuration 3 SEM Configuration ...
Page 901: ...Configuration Guide ERSPAN Configuration ...
Page 902: ...Web based Configuration 1 Web based Configuration ...