3Com 4007, Implementation Manual, Page: 301 / 684

Rules of VLAN Operation 301
The frames that are associated with these protocols have different ingress
rules for assignment to the appropriate network-based VLAN:
■
IP frames — These frames are assigned to the network-based IP
VLAN if the IP source address is consistent with the VLAN subnet and
the IP destination address is one of the following:
■
0.0.0.0
■
255.255.255.255
■
A Class D (multicast) address
Otherwise, assign to the network-based IP VLAN if the IP destination
address is consistent with the VLAN subnetwork. Otherwise, assign to
the
All IP Subnets VLAN.
■
ARP frames — These frames are assigned to the network-based IP
VLAN if the IP destination address is consistent with the VLAN subnet
and the IP source address is 0.0.0.0. Otherwise, assign to the
network-based IP VLAN if the IP source address is consistent with the
VLAN subnetwork. Otherwise, assign to the
All IP Subnets VLAN.
■
RARP frames — These frames are assigned to the All IP Subnets
(Multicast) VLAN.
Example 3: Decisions for One Network-based VLAN
Table 60 lists the information for one network-based IP VLAN and how
forwarding and flooding decisions are made for this VLAN.
Table 60 One Network-based VLAN and Forwarding/Flooding Decisions
Index VID VLAN Name Ports IP Subnet
2 2 IP_100 1 (untagged)
2-6 (tagged)
158.101.100.0
mask: 255.255.255.0
Frame received on Port 1 Action
IP Frame (Protocol 0x0800), IP
destination address (DA)
158.101.103.1, MAC DA is known
on port 6 Frame is assigned to the IP_100 VLAN and
transmitted on port 6 tagged.
RARP Response Frame (Protocol
0x8035), IP DA = 158.101.103.2,
MAC DA is unknown Frame is assigned to the IP_100 VLAN and
transmitted on port 6 tagged.