Router configuration in GNS3 VS real world

ccna_student

When i have an isolated router in GNS3 (nothing plug to it), if the interface has been turn on administratively turned on (no shut), so i can see that the status (layer1) is up. Is it supposed to be like that ?

What will happen with a real router if no cable connect to that router or that the cable was damaged ?
Is the layer1 suppose still to show "up" ?

Thanks

RouteMyPacket

Real world = down/down

StussyNz

Intresting.. Could this be reported for a bug fix? As per the above comment; Interface on the Router would state down/down until a physical connection was present.

NetworkVeteran

Intresting.. Could this be reported for a bug fix

This is a Dynamips limitation that's been known for years, so chances seem slim for a fix at this time.

ccna_student

Hi, thanks for your replays

Do you think it is a real bug, or maybe it is because the router interface is "talking" shomehow with the NIC of the computer ?

And another issue,
The "show interfaces status" command does not showing nothing in GNS3 . . .
Is it a bug ?

bermovick

Show interface status is a switch command. The router equivalent (more or less) is show ip interface brief.

NetworkVeteran

Whether it's classified as a "bug" or "feature request" makes little difference since this is a free product. In paid products it might make the difference between who pays to have the behavior added or changed.

The software is the real IOS, so what you see there is real--configurations, protocol commands, protocol behaviors, what is or isn't accepted, what the output looks like, quirks, bugs, etc. This is one of the strengths of GNS3. Others include the ability to mock-up scenarios without the cost in money and time of buying and assembling equipment. In other words, you can master the same exam objects for less time/money or become more knowledgeable given the same time but still less money.

The hardware is emulated by Dynamips, and so paying great attention to that isn't a good use of time. That includes PHYs, auto-negotiation, duplex, line speed, installed memory or processor type, etc. You can run those commands, but expect less faithfulness. Perhaps jot down your doubts and then augment with one or two rack rentals to clear them up. This is one way you can effectively combine the advantages of emulated equipment and real equipment.

networker050184

Very good assessment by NetworkVeteran. Don't worry too much about the hardware side of things with GNS3 or you'll end up chasing your tail for nothing. It is emulated so there are things to be expected that do not function exactly like the real world. What it does do is give you the actual IOS to get your hands in the CLI.