Intel NetStructure 470 - Manual (Page 135)

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Technical Information A P P E N D I X
Appendix
I keep getting an intermittent loss of link (or data is not
being transmitted). Why?
• You may be using the wrong grade of cable. The wrong cable can cause
erratic performance and you may eventually lose the connection
between the port and the attached device. For more information on
cabling, see “Connection Guidelines” in Chapter 1.
• Check the duplex setting for the device connected to the port. You may
need to use Local Management or Web Device Manager to force the
port to half- or full-duplex (470T only).
• A cable segment somewhere in your collision domain may be too long.
Make sure your UTP cabling is no longer than 100 meters and your
mulitmode fiber cable is no longer than 550 meters.
I created a tag-based VLAN, and I have tag-capable LAN
adapters in my PCs, but I can still communicate with
devices outside the VLAN. Why?
There are two areas to check in this situation. This can occur if ingress
filtering is disabled. Enable ingress filtering so that the switch drops
incoming packets if the packet’s VID is not a member of the port.
The PC’s NIC may not be enabled for tagging. If the NIC is not enabled
for tagging, the PC sends and receives untagged traffic, and the switch
classifies the traffic using the PVID. Ensure that the NIC is enabled for
tagging.
Locating MIB files
If you use a MIB browser, you can configure or view statistics for the
switch. You can find these switch MIB files at the Intel Support Web site at
http://support.intel.com/support
• intel.mib
• intel_gen.mib
• int_s470.mib
• int_pbrd.mib
• int_qprd.mib
When compiling the MIBs into an SNMP-compliant management
application, compile the intel.mib first then compile the intel_gen.mib,
int_s470.mib, int_pbrd.mib, and int_qprb.mib files.