Allied Telesis at-8700xl series switch IP Addresses and DHCP, Time and NTP, Diagnosis, Solution

42AT-8700XL Series Switch User Guide

IP Addresses and DHCP

Problem The switch is enabled as a DHCP server, but cannot assign an IP address to a host.

Solution ■ Reboot the host machine.

■ Check the host’s TCP/IP settings, to make sure that the host is set to obtain its IP address dynamically:

In Windows 95/98, click Settings > Control Panel > Network. Select TCP/

IP and click Properties. Click Obtain an IP address automatically.

In Windows 2000, click Settings > Control Panel > Network and Dial-up Connections > Local Area Connection > Properties. Select Internet connection (TCP/IP) and click Properties. Click Obtain an IP address automatically.

■ Check that the switch’s link to the LAN is functioning, by checking the interface status (Monitoring) and that the link LED is lit (see “Traffic Flow” on page 41).

	Time and NTP
Diagnosis	The switch’s time is displayed on the Configuration > System > Time tab. It
	will also be included in log packets.
Problem	The switch’s time does not change, even though you entered the correct time.
Solution	Changing the time is a 3-step process. Select Configuration > System > Time.
	First, enter a time that is very shortly in the future (e.g. 20 seconds later than
	the current time). Then check Set time. Then wait until precisely the time you
	have entered, and click Apply.
Problem	The switch is not assigning the time to devices on the LAN.
Solutions	■ Check NTP is enabled (Configuration > System > Time).
	■ Check that the NTP peer’s IP address is entered correctly.
	■ Check that the NTP peer can reach the switch, by pinging the switch from
	the NTP peer.
	■ Check that the switch’s link to the LAN is functioning. See “Traffic Flow” on
	page 41.

Problem The switch’s clock does not synchronise with the NTP peer.

Solution ■ The switch’s clock can only synchronise with the NTP peer if its initial time is similar to the NTP peer’s time (after setting the UTC offset). Manually set the switch’s time so that it is approximately correct, and enable NTP again.

■Check that the UTC offset is correct.

Problem The switch’s time is incorrect, even though it assigns the correct time to devices on the LAN.

Solution The UTC offset is probably incorrect, or needs to be adjusted for the beginning or end of summer time. To correct this, select Configuration > System > Time and enter the correct offset.

Software Release 2.6.1 C613-02030-00 REV B