System goes down automaticly on full duplex, why ?

GOZCU

I have a basic question which i came across while studying for CCNET.

First picture shows the basic connection diagram,

Second picture shows the codes that i ran ( pls look to the attachments)

After all of these codes,( making it full duplex) system stops to communicate each other. when i run, "show ip interface brief" i see that status is down.

And when i make it "half duplex" system again goes online. any reason? idea ?

Monkerz

We would refer to this as duplex mismatch. The PC's NIC is probably hard coded to 100/half-duplex, which is going to cause a lot of collisions in the link.

I would set both the switchport and your PC's NIC to auto and let them negotiate the speed and duplex.

GOZCU

Monkerz wrote: »

We would refer to this as duplex mismatch. The PC's NIC is probably hard coded to 100/half-duplex, which is going to cause a lot of collisions in the link.

I would set both the switchport and your PC's NIC to auto and let them negotiate the speed and duplex.

But does it mean that system was communicating in half duplex before i configured it to full ? because, just after the connection and before any code on CLI, system was up.

Monkerz

Reconfigure the switchport to auto and 'show interface status'. It will show you the speed and duplex of the connection.

SteveO86

Either the system is manually configured for Half-Duplex or their is something with the physical cabling.

If your doing this packet tracer then it can't be a cable issue

andy4tech

As Monkerz said there may be duplex mismatch,the host and switch are to be in full duplex.Also check the cabling.

melcredo

this is included in the ccent exam? thanks

phobophile

My guess is that you are doing this in PT?

Whenever I hardcode a switch port for full-duplex, the interface does indeed go down. Check the config on the host, and verify that duplex is set to Full Duplex. For whatever reason, the host defaults to Half-Duplex whenever hardcoding the switchport for Full-Duplex (at least in my experience).

GOZCU

phobophile wrote: »

My guess is that you are doing this in PT?

Whenever I hardcode a switch port for full-duplex, the interface does indeed go down. Check the config on the host, and verify that duplex is set to Full Duplex. For whatever reason, the host defaults to Half-Duplex whenever hardcoding the switchport for Full-Duplex (at least in my experience).

thanks for the explanation, that is exactly what i experienced too. and yes, tried on packet tracer...

GOZCU

melcredo wrote: »

this is included in the ccent exam? thanks

yes, these are the basic and the essential things for being prepared to CCENT

Turgon

GOZCU wrote: »

I have a basic question which i came across while studying for CCNET.

First picture shows the basic connection diagram,

Second picture shows the codes that i ran ( pls look to the attachments)

After all of these codes,( making it full duplex) system stops to communicate each other. when i run, "show ip interface brief" i see that status is down.

And when i make it "half duplex" system again goes online. any reason? idea ?

I havent looked at the configs but the rule of thumb is full at both ends or auto at both ends. If there is a mismatch between the ends you can expect some half duplex and other fun.

melcredo

GOZCU wrote: »

yes, these are the basic and the essential things for being prepared to CCENT

.. thanks for the reply... whew need to study this simulations