Hi!
This was getting me on my nerves, but I finally found out how to resolve the "host unreachable" warning.
Create a static IP for your PC. On network settings, go find your Network and change from obtain IP automatically to Use following IP address. You can find plenty turorials on google about this.
Create a static IP for your router (if not static yet. If you restart your PC and IP changes you have to make it static) search for NoIp (https://www.noip.com/) on google and follow the steps to have a free IP domain. Download the app of NoIp and keep it running on your PC.
Most of the times your PC clock is not well synchronized with real time, so there are "delays" on time, you can use "NetTime" (http://timesynctool.com/) and set it up with your nearest geographical Time Pool (http://www.pool.ntp.org/es/).
Forwards ports 9981 and 9982 to your Static PC IP (both TCP and UDP), your network provider can help you with that or look for help here: https://portforward.com/
Create rules on your firewall to the same ports for both Outbound and Inbound rules, same as step 4 on TCP and UDP.
I was trying hard to make this work, I use Storj too and It worked like charm but then I had to upload it and follow the instructions on their website (https://docs.storj.io/docs/storj-share-gui).
First I just forwarded the ports and It keept showing the "Host unreachable" warning but I think installing NoIp and NetTime, made it work. Now I got 19 contracts and it haven't failed yet. The only concern I got is that sometimes Sia debit me some coins, maybe because of the contracts.
I'm new to this and I'm not a tech savvy I'm a designer, I just tried and tried to make it work, I believe in Siacoin and the blockchain. But as a personal advice, SiaCoin need an excellent UX designer to make it work as it should, so that everyone without special knowledge can use the network. You can Hire me ;)
Siacoin keep going, but help people that want to use your network, make it massive!!!
PS: Sorry for my English