ARP
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... reducing the re-attachment time on LANs to a few milliseconds. Since
this procedure is dependent on the ARP protocol, it is not suitable
for use on media that do not support ARP.
...
... this procedure is dependent on the ARP protocol, it is not suitable
for use on media that do not support ARP.
...
... DHCP specifies that the client SHOULD
use ARP to verify that the offered address is not already in use.
The process of address conflict detection ...
... address is
valid for use, by sending a unicast ARP Request packet to a router
previously known for that link ...
... link with more
than one router, by sending one or more unicast ARP Request packets
to one or more of those routers).
...
...
The use of unicast ARP has a number of benefits. One benefit is that
unicast packets impose less burden on the network ...
... host is not on the link it hoped to find itself on, a broadcast ARP
Request could pollute the ARP caches ...
... legitimately using the same address, and a broadcast ARP Request
could disrupt its communications, causing TCP connections to be
...
... TCP connections to be
broken, and similar problems. Also, using a unicast ARP packet
addressed to the MAC address of the router ...
... link there will be
no device with that MAC address, and the ARP packet will harmlessly
disappear into the void without doing any damage.
...
... cases. For example, if a router ignores unicast ARP Requests,
then DNAv4 will not be able to detect that it has returned to
...
... unicast packets. An IPv4 ARP packet on Ethernet is just 42
octets, including the Ethernet header ...
... IPv4 configuration on that network.
Restrictions on sending ARP Requests and Responses are described in
Section 2.1.1.
...
... RFC3118] is configured. The reachability
test utilizes ARP, which is insecure. Hosts that have been
configured to attempt DHCP authentication ...
... The reachability test is performed by sending a unicast ARP Request.
The host MUST set the target protocol address ...
... field (ar$spa) to its own candidate IPv4 address. The ARP Request
MUST use the host MAC address ...
...
If a valid ARP Reply is received, the MAC address in the sender
hardware address field (ar$sha) in the ARP ...
... ARP Reply is received, the MAC address in the sender
hardware address field (ar$sha) in the ARP Reply is matched against
the target hardware address field (ar$tpa) in the ARP ...
... ARP Reply is matched against
the target hardware address field (ar$tpa) in the ARP Request, and
the IPv4 address in the sender protocol address ...
... IPv4 address in the sender protocol address field (ar$spa) of the
ARP Reply is matched against the target protocol address field
(ar$tpa) in the ARP ...
... ARP Reply is matched against the target protocol address field
(ar$tpa) in the ARP Request. If a match is found, then the host
continues to use that IPv4 address ...
... IPv4 configuration by receipt of a
response to the reachability test, it SHOULD NOT respond to ARP
Requests and SHOULD NOT broadcast ARP ...
... ARP
Requests and SHOULD NOT broadcast ARP Requests containing its address
within the sender protocol address ...
... candidate configuration, since sending any IP packet
generally requires an ARP Request/Reply exchange and, as explained
above, ARP packets may not be broadcast ...
... generally requires an ARP Request/Reply exchange and, as explained
above, ARP packets may not be broadcast safely until after the
candidate ...
... Detecting Network Attachment for IPv4 (DNAv4) is based on ARP and
DHCP and inherits the security vulnerabilities ...