I’m currently working with a Cisco 1841 router, and I’ve encountered an issue where my device does not support IPv6 due to its current IOS version. I’ve been trying to find a suitable IOS image with IPv6 support on the official Cisco Software Download Center, but it seems like the images for this particular router model are no longer directly available for download.
I understand that the IOS version should probably be in the 15.x releases for IPv6 support, and that the feature set should be “IP Base” or “Advanced IP Services”. Unfortunately, I haven’t been able to locate these on the Cisco website.
I was wondering if anyone else here has faced a similar situation and could guide me on the best way forward.
Thanks for any assistance provided.
That’s a tough one, I would never have thought it would be so hard to find a firmware file. It looks like all the Cisco links are down because its EOS and random FTP links that people hosted the file on are down because the device is just so old
I’m busy downloading some large packs of IOS firmware, unsure currently if they contain what you want, but if they do I will share
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That’d be awesome, thanks.
Sadly all I can find is the older ones, like this
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How much memory do you have in that? Just a note, it looks like you needed to have it maxed out
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Just FYI if you google for the filename of a firmware, you’ll often find the files for download on random websites. (Used to be lots of FTP sites before FTP support was removed from google / browsers). If you download those links you are violating the Cisco ToS, so I can’t recommend it …
The Cisco Download site also typically provides filenames and checksums for firmware, however I can’t find the specific link for 1841. Maybe it was taken down? (Rare for Cisco). So if you happen to have a file, its normally easy to verify that its genuine.
Also if you’re using the 1841 as your main router, I’d strongly recommend moving to something else. Due to its ancient software it will likely have bugs and security issues. It may also have weird IPv6 incompatibilities, since the standards for that protocol have had many minor changes over the years.
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That’s all good, cheers for having a look 
I’m not sure, I’ll have to check later. I’ll read that link, ty.
Cheers for that info.
I’m just using it to help with my study for CCNA. Packet tracer has some limitations, so I got a few of these routers recommended on a different forum. I should have done a bit more research into its IPv6 capabilities though haha.
It should be fine for labbing. I’ve had issues with RAs on equipment that old, but static configuration should be fine.
You can download the IOS-XE 1000V, IIRC you get all the features with severe rate limiting by default. Maybe with a trial license for 60 days? https://software.cisco.com/download/home/284364978/type/282046477
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I’ll give this a go, it looks interesting. I didn’t think of this sort of option.