Half Duplex vs. Full Duplex

[john-lucero]

What are the pros and cons of using a full duplex setting between switches? Is there a reason you would not want to or a reason you would want to.

I am currently using half duplex setting (Auto Negotiated) between Catalyst 5000 series switches over 100Base-FX

You assistance is appreciated.

[deilert]

by using full duplex you will not have any collisions over the pipe. You will enhance your performace with this setting .

make sure you hard code your settings, auto is less than reliable .

[john-lucero]

Is there anything not good about using full duplex settings?

[deilert · Accepted solution]

the only drawback could be a bottleneck somewhere when your traffic starts hitting the 10 MB Half duplex devices , however since you are connecting 2 switches this should not be an issue

[deilert]

FYI

when changing the setting from half or auto to full the proper way to do this is

switch(enable) set port dis x/x

switch (enable) set port speed x/x 100

switch (enable) set port duplex x/x full

switch(enable) set port en x/x

[Kevin Dorrell]

As far as I am aware, there is no autonegotion on 100BaseFX. Which card are you using? If it is the WS-X5201, then the only options are full and half .. there is no auto.

The only reason I can think of that youmight want to use half-duplex on a 100BaseFX link is if you are connecting to some other equipment that does not support full-duplex. Since you have a Cat5000 at each end of the link, I would use full duplex.