3com 4500 Guide D’Installation Rapide
Solving Communication Problems
55
Solving
Communication
Problems
Communication
Problems
If you experience communication problems with the Switch, ensure that:
■
The Switch IP address and Management VLAN ID has been configured.
■
If the Switch is separated from your management application by a router,
ensure that the default gateway IP address within the Switch is the same as the
IP address of the router.
ensure that the default gateway IP address within the Switch is the same as the
IP address of the router.
■
The Switch’s IP address has been entered correctly in your network
management application (such as 3Com Network Director).
management application (such as 3Com Network Director).
The following is a brief overview of IP addressing, and how to obtain a registered
IP address.
IP address.
IP Addressing
To be managed correctly, each device on your network (for example a Switch or
Hub) must have a unique IP address. IP addresses have the format n.n.n.n where n
is a decimal number between 0 and 255. An example IP address is 192.168.100.8.
Hub) must have a unique IP address. IP addresses have the format n.n.n.n where n
is a decimal number between 0 and 255. An example IP address is 192.168.100.8.
The IP address is split into two parts:
■
The first part (‘192.168.100’ in the example) identifies the network on which
the device resides
the device resides
■
The second part (‘.8’ in the example) identifies the device within the network
The natural subnet mask for this example is 255.255.255.0.
If your network has a connection to the external IP network, that is, you access the
Internet, you must apply for a registered IP address.
Internet, you must apply for a registered IP address.
How do you obtain a registered IP Address?
The IP registration system ensures that every IP address used is unique; if you do
not have a registered IP address, you may be using an identical address to
someone else and your network will not operate correctly.
not have a registered IP address, you may be using an identical address to
someone else and your network will not operate correctly.
InterNIC Registration Services is the organization responsible for supplying
registered IP addresses. The following contact information is correct at time of
publication:
registered IP addresses. The following contact information is correct at time of
publication:
World Wide Web site: http://www.internic.net
If your IP network is internal to your organization only, that is, you do not access
the Internet, you may use any arbitrary IP address as long as it is not being used by
another device on your network. 3Com suggests you use addresses in the range
192.168.0.0 to 192.168.255.255 with a subnet mask of 255.255.255.0.
the Internet, you may use any arbitrary IP address as long as it is not being used by
another device on your network. 3Com suggests you use addresses in the range
192.168.0.0 to 192.168.255.255 with a subnet mask of 255.255.255.0.
These suggested IP addresses are part of a group of IP addresses that have been
set aside specially for use ‘in house’ only.
set aside specially for use ‘in house’ only.
A device is connected to a Switch 4500 PWR but power is not being
supplied
supplied
If power is not being supplied to a device connected to a Switch 4500 PWR, you
should do the following checks:
should do the following checks:
■
Check that the device is compliant with the 802.3af standard ref. [18].