2500 IOS installation

[justincraggs]

I've been trying to install an IOS on a 2503 router that I've bought to do my CCNA. I've tried multiple ios versions of different shapes and sizes including one backed up from a working 2500. I've tried installing across my network, via a direct link, via hyperterminal, via telnet, on a mac and on a pc and with multiple tftp servers on both platforms. Each time the ios downloads ok. ie I get all "!" as it downloads but it then fails the checksum:

!!!!!!!!!!!!!!!!!!!!!!!!!!
[OK - 7990616/8388608 bytes]
Verifying checksum... invalid (expected 0x2758, computed 0x1B48)

The router didn't have an IOS installed when i got it. The guy I got it from said it worked ok before he erased the IOS during a CCNA lab. He's probably talking bulldust though. I'm just too trusting for my own good.

Other than a connection or tftp software problem, are there any other likely reasons? ie hardware related.

Any help will be appreciated.

 

[NettableWalker]

What TFTP server are you using? and how far away is it from the 2500 in terms of LAN/WAN hops etc? Because it might be that the signal is getting corrupted.

This is only UDP so relies on a reliable link.

MCP,CCA, Net+, 1 quarter CCNP...

 

[justincraggs]

I'm using Solarwinds on the peeceee and TftpServer on the mac. I was connecting through a switch but because of this problem tried a direct link with a crossover cable...and tried it on both the mac and pc. Still didn't work.

I've kind of solved the problem. I have another 2500. I swapped the flash modules around. So the suspect flash went into a 'good' router. I managed to install an ios on it ok and it booted fine but when I put the suspect modules back into the original router it booted back the limited IOS and when I did a "sh flash" command it showed the ios as being corrupted. So again I went through the process of trying to do an install and each time the checksum failed

So I went through the process again of swapping the modules between routers and again managed to successfully install the ios. So for the moment I'll leave it at that. Both routers are running fine...for the moment.

This doesn't solve the problem of why the flash doesn't work in the router it come in.

I might have a clue though...The flash is made up of two flash modules. When I ran the "sh flash" command on the new router with the suspect flash, it showed that there was 8Mb memory as one partition. When I put the memory into my existing router and ran the "sh flash" command, it showed the memory as being two 4mb partitions. So I ran the "partition flash 1 8" command to create a single partition. That's when i was able to successfully install the ios. So as I said, i put the memory back in the new router which then showed a corrupt ios, put it back into my existing router and ran 'sh flash'....it was back to the two 4mb partitions! So I created a single partition, installed the ios and that's where I'm up to.