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To bypass the ARP inspection, use the following command.
•
Specify an interface as trusted so that ARPs are not validated against the binding table.
INTERFACE mode
arp inspection-trust
Dynamic ARP inspection is supported on Layer 2 and Layer 3.
Source Address Validation
Using the DHCP binding table, Dell Networking OS can perform three types of source address validation (SAV).
Table 26. Three Types of Source Address Validation
Source Address Validation
Description
IP Source Address Validation
Prevents IP spoofing by forwarding only IP packets that have
been validated against the DHCP binding table.
DHCP MAC Source Address Validation
Verifies a DHCP packet’s source hardware address matches the
client hardware address field (CHADDR) in the payload.
IP+MAC Source Address Validation
Verifies that the IP source address and MAC source address are
a legitimate pair.
Enabling IP Source Address Validation
IP source address validation (SAV) prevents IP spoofing by forwarding only IP packets that have been validated against the DHCP
binding table.
A spoofed IP packet is one in which the IP source address is strategically chosen to disguise the attacker. For example, using ARP
spoofing, an attacker can assume a legitimate client’s identity and receive traffic addressed to it. Then the attacker can spoof the
client’s IP address to interact with other clients.
The DHCP binding table associates addresses the DHCP servers assign with the port or the port channel interface on which the
requesting client is attached and the VLAN the client belongs to. When you enable IP source address validation on a port, the system
verifies that the source IP address is one that is associated with the incoming port and optionally that the client belongs to the
permissible VLAN. If an attacker is impostering as a legitimate client, the source address appears on the wrong ingress port and the
system drops the packet. If the IP address is fake, the address is not on the list of permissible addresses for the port and the packet
is dropped. Similarly, if the IP address does not belong to the permissible VLAN, the packet is dropped.
To enable IP source address validation, use the following command.
NOTE: If you enable IP source guard using the
ip dhcp source-address-validation
command and if there are
more entries in the current DHCP snooping binding table than the available CAM space, SAV may not be applied to all
entries. To ensure that SAV is applied correctly to all entries, enable the
ip dhcp source-address-validation
command before adding entries to the binding table.
•
Enable IP source address validation.
INTERFACE mode
ip dhcp source-address-validation
•
Enable IP source address validation with VLAN option.
INTERFACE mode
ip dhcp source-address-validation vlan
vlan-id
NOTE:
Before enabling SAV With VLAN option, allocate at least one FP block to the ipmacacl CAM region.
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Dynamic Host Configuration Protocol (DHCP)
Summary of Contents for S4048-ON
Page 1: ...Dell Configuration Guide for the S4048 ON System 9 9 0 0 ...
Page 146: ...Figure 14 BFD Three Way Handshake State Changes 146 Bidirectional Forwarding Detection BFD ...
Page 522: ...Figure 87 Configuring Interfaces for MSDP 522 Multicast Source Discovery Protocol MSDP ...
Page 523: ...Figure 88 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 523 ...
Page 528: ...Figure 91 MSDP Default Peer Scenario 1 528 Multicast Source Discovery Protocol MSDP ...
Page 529: ...Figure 92 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 529 ...
Page 530: ...Figure 93 MSDP Default Peer Scenario 3 530 Multicast Source Discovery Protocol MSDP ...
Page 633: ...Policy based Routing PBR 633 ...
Page 777: ...Figure 119 Single and Double Tag TPID Match Service Provider Bridging 777 ...
Page 778: ...Figure 120 Single and Double Tag First byte TPID Match 778 Service Provider Bridging ...