HP ProCurve 5412zl Excessive Broadcasts and High Collision or drop rate

[ryjguy7]

Hi, We have A HP ProCurve 5412zl with 4 VLANs configured and trunked together. We have a Switch 2900-48G in another location wired into the ProCurve main module. We have been getting excessive broadcasts and high collision or drop rates on various ports since it's installation and configuration 3 mths ago. It has been setup with all the default settings. I have noticed that some of the port are in MDIX mode some are in MDI mode and the rest are in Auto mode. The Trunked ports are all in MDIX mode. Now, should the regular ports be on Auto mode? What mode would produce the best result as far as bandwidth and performance? Should they all be in MDIX mode?

[Pieter 't Hart]

MDI or MDI-X depends on the device you connect to this port.
basically it has no impact on bandwith or performance.

a workstation normally has MDI-port.
for this a switch standard has MDI-X ports so you can use a straight cable to connect a workstation to a switch.

if you connect two switches you need a cross-over cable to connect two MDI-X ports.
OR on of the devices most have someway to modify an MDI-X port into an MDI-port.
some devices use a slide-switch for this,
but many vendors have added a mdi/mdi-x auto feature so the port autodetects if a mdi or an mdi-x device is connected and decide if it uses it's own port in mdi or mdi-x state (one device selects mdi other mdi-x).

there are three thing that can be set to auto or manual
- speed
- duplex
- mdi/mdi-x

if you know what's connected at the other end and what cable is used you don't need auto settings for this.
If you configure manually link wil be up faster because this autodetect step can be skipped.

autodetect speed/duplex sometimes fails between ports with different speed. in that case manual speed/duplex will improve reliability.
with both ports gigabit-capable speed/duplex is better left to auto and only mdi/mdi-x may be set to manual..

hope this clarifies
Pieter