I got some great questions from Rob Methven so I thought I’d answer them here in the form of a “Q&A”.
Q. I got the Etherswitches and VPCs pinging each other no problem. However, when I do a show mac-address table on the switches, the CAM table either show up as completely empty or with just the last couple of MAC addresses. Repeated show mac-address-table show that the table gradually removes the entries until it’s empty, normally within 30 seconds. I’m using the recommended IOS for the c3725 (T10), but I’ve also tried with the T14 release and observed the same behaviour.
A. This is a known problem with dynamips and has been reported on the GNS3 Forum. I’ve asked Flàvio (maintainer of dynamips) to look into it again.
Q. RE VPCS: When I load the exercises, am I right in thinking that I have to manually configure the IP addresses on the individual VPCs? I’ve done it no problem, and saved the config so I can quickly load it, but I’m just checking that I’m not doing anything wrong!
A. Some exercises will require that the IP addresses for the VPCs, others will have pre-configured exercises. To be honest, there are a couple of places where I meant to have IPs already configured but didn’t. What happens when you load a snapshot is that the contents of the snapshot’s configs directory gets copied to the current project’s configs directory. If I remembered to put the relevant startup.vpc file in the snapshot’s configs directory then the VPCs will start with the correct addresses.
Q. When I load a snapshot for a topology, I get a message saying that the IOS image can’t be found. I get an option to choose the correct image, which is invariably the same file. The only difference that I can see is the path. The images that I can use have the full paths (C:\Users\Rob\GNS3\Images\imageName.image) to the image listed in the dialog , even though it’s in my specified “Images” folder. I can fix this by editing the topology file to point to the full path, so again, it’s not a massive issue. Just wondering if I’m doing something wrong!
A. This is a real bummer – this problem was solved back in GNS3 0.8.3 and re-introduced somewhere between v0.8.3 and v0.8.6 – and since Jeremy is now busy working on GNS3 v1.0, I’m guessing there won’t ever be a real fix for this. Unfortunately going back to GNS3 v0.8.3 is NOT an option, because that version doesn’t support he Help features and the Snapshot features that GNS3 WorkBench now relies on. If you look at the toplology.net files that are supplied in the Windows/OS X version of GNS3 you will see that there is NO path specified in the
image = c3725-adventerprisek9-mz.124-15.T10.image
lines in all the exercises and snapshots. I’ve just written a script to allow a user fix this for Linux based systems (may work on OS X) but don’t have anything for Windows yet (any Windows script writers out there wanting to take a bash script and “Windoize” it please contact me!).
What you need to do is the windows equivalent of the linux command:
find . -type f -name topology.net -exec sed -i "s#c3725-adventerprisek9-mz.124-15.T10.image#C:\full\path\to\c3725-NEWIMAGE.image#" {} \;
but I don’t know if Windows has such commands.
Q. Just show me where to donate!
A. I do this to help the community. I had at one stage thought of trying to set up a link to a charity, but it got too hard. You could of course buy my book if you think it will be useful, or sign up for SlideShark using this link where you’ll get an extra 25MB free for using the link.
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