VLAN Configuration 329
By default, the system has no static domain name resolution mapping.
Pay attention that when adding a domain name mapping, if the same hostname
has been input twice, the current configuration will overwrite the previous one. A
static domain name resolution table can maintain a maximum of 50 mapping
relationships between domain names and IP addresses.
Display and Debug
Domain Name
Resolution
Tabl e 361 Display and Debug domain name resolution
VLAN Configuration To facilitate the mobility of computers in the network and save bandwidth, we can
create VLAN in LAN Switch to meet various requirements. After creating VLAN in
LAN Switch port, data communication can be easily implemented within the same
VLAN. However, the different VLANs are isolated from each other, so it is necessary
to transmit packet between different VLAN in the same way as transmitting it
between different LAN segments. The forwarding function between VLANs on the
3Com Router series is implemented by Ethernet interface and it supports IP and
IPX packet. In order to save port resources, several subinterfaces can be
encapsulated on one Ethernet interface and every subinterface acts as an
independent Ethernet interface. Therefore, a physical Ethernet interface can
implement data forwarding between several VLANs as shown in the figure below.
Figure 121 Networking diagram mode of VLAN
In accordance with the IEEE 802.1Q, to implement the VLAN functionality of the
3Com Router series, a 4-byte VLAN tag is placed between the source/destination
MAC address of the original Ethernet frame header and the Type field to mark the
VLAN message. The format of VLAN tag is shown as below.
Delete static domain name resolution table item undo ip host domain-name
ip-address
Operation Command
Display static domain name resolution table item display ip host
Router
Fast
Ethernet
Bridge/LAN Switch
File Server
Workstation
Workstation Floor 3
(Accounting)
Product 1 Product 3Product 2
Bridge/LAN Switch File Server
Workstation
Workstation Floor 2
(Marketing)
Bridge/LAN Switch File Server
Workstation
Workstation Floor 1
(R&D)
VLAN 1 VLAN 3
VLAN 2