Ip Address Configuration Example; Troubleshooting Ip Address Configuration; Arp Configuration - 3Com 5500-SI Configuration Manual

IP Address Configuration
Example
Troubleshooting IP
Address Configuration

ARP Configuration

Networking Requirements
Configure the IP address as 129.2.2.1 and subnet mask as 255.255.255.0 for VLAN
interface 1 of the Switch.
Networking Diagram
Figure 63 IP Address Configuration Networking
C o n s o l e c a b l e
PC
Configuration Procedure
1 Enter VLAN interface 1.
[SW5500]interface vlan-interface 1
2 Configure the IP address for VLAN interface 1.
[SW5500-vlan-interface1]ip address 129.2.2.1 255.255.255.0
Fault 1: The Switch cannot ping through a certain host in the LAN.
Troubleshooting can be performed as follows:
Check the configuration of the Switch. Use the
■
the ARP entry table that the Switch maintains.
Troubleshooting: First check which VLAN includes the port of the Switch used to
■
connect to the host. Check whether the VLAN has been configured with the VLAN
interface. Then check whether the IP address of the VLAN interface and the host
are on the same network segment.
If the configuration is correct, enable ARP debugging on the Switch, and check
■
whether the Switch can correctly send and receive ARP packets. If it can only send
but cannot receive ARP packets, there are possibly errors occurring on the Ethernet
physical layer.
Necessity of ARP
An IP address cannot be directly used for communication between network devices
because network devices can only identify MAC addresses. An IP address is an
address of a host in the network layer. To send the data packets transmitted through
the network layer to the destination host, the physical address of the host is required.
So the IP address must be resolved into a physical address.
ARP Implementation Procedure
When two hosts on the network communicate, they must know the MAC addresses
of each other. Every host will maintain the IP-MAC address translation table, which is
known as ARP mapping table. A series of maps between IP addresses and MAC
addresses of other hosts which were recently used to communicate with the local
host are stored in the ARP mapping table. When a dynamic ARP mapping entry is not
in use for a specified period of time, the host will remove it from the ARP mapping
table so as to save the memory space and shorten the interval for Switch to search
ARP mapping table.
S w i t c h
display arp
ARP Configuration 273
command to view