cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
1018
Views
0
Helpful
9
Replies

Cisco 6509 port errors

smavashev
Level 1
Level 1

At work recently I have run into a problem where on my 6500 switches I see, continuous ports errors accumulating, the network does not seem to be slow but the errors are in the millions for more then 70% of all ports. This is happening on many switches throughout the enterprize. At my job we have old equipment dating back to the year 2000. The ios versions are 5.1 to 5.3. If need be I can post some output tomorrow. But I'm thinking it is an old IOS and needs to be upgraded either on the SUPS or the chassis themselves as well. Please advice what I should do. Thanks guys.

9 Replies 9

Leo Laohoo
Hall of Fame
Hall of Fame
the network does not seem to be slow but the errors are in the millions for more then 70% of all ports.

You are not talking about "Total Output Drops", are you?

No, Im talkin about single-collisions, multiple-collisions, when I do a show port 3/7 for example.

Collisions generally means that you've got duplex issues.  Are duplex hard-coded on the interfaces?

Yes they are. For users its 10/half. For printers its 100/Full. For wireless access points they auto sensed usually at 100/Full.

its 10/half.

If you (intentionally) configure your interface as "half duplex" then this will guarantee you get collision errors, period.

It's not a "Cisco thing".  It's the ethernet standard.

One more thing, you've hard-coded the printer to be "full duplex"?   Modern NICs (printers, PCs, etc), you don't need to hard-code their speed and duplex settings.  Just leave them be and these NICs tend to behave themselves, unlike in the olden days.

So basically If an interface is configured at half duplex going through a cat 5 cable, some will most certainly collide. So what would be an optimum configuration for ports that cause no collisions with cat 5 cables for regular users?

We have new Xerox printers that require speeds to be configured at 100/full because their responce times slow down tremendeously at 10/half

So basically If an interface is configured at half duplex going through a cat 5 cable, some will most certainly collide.

Yes, guaranteeed.

So what would be an optimum configuration for ports that cause no collisions with cat 5 cables for regular users?

Auto speed, auto duplex.

We have new Xerox printers that require speeds to be configured at 100/full because their responce times slow down tremendeously at 10/half

Those are extreme cases.  Mostly, you leave speed and duplex settings to auto so they can sort themselves out.

I can't see any reason why you would have anything configured as HALF DUPLEX.

Hard set these ports to FULL DUPLEX and the correct SPEED.

You may have to do this on both ends if you are connecting to another SWITCH/ROUTER

When troubleshooting duplex should be your first place to look.

For all work switch ports that connect to works stations at my work we use speed 100 duplex full.  They don't need 1GB at the desktop so I don't give it to them.  Take the change that our 1GB uplinks from the switches can be flooded by a single user aswell.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Review Cisco Networking products for a $25 gift card