When I try to distribute my public key to a key server:
```
gpg --keyserver keyserver.ubuntu.com --send-keys <keyID>
```
It always gives error:
```
gpg: keyserver send failed: Network is unreachable
gpg: keyserver send failed: Network is unreachable
```
What I tried:
1. change keyserver to
```
keys.openpgp.org
```
or
```
pgp.mit.edu
```
2. try
```
gpg --keyserver hkp://keyserver.pgp.com:80 --send-keys <keyID>
```
3. try sudo
```
sudo gpg --keyserver keyserver.ubuntu.com --send-keys <keyID>
```
I could access keyserver.ubuntu.com, keys.openpgp.org and pgp.mit.edu from browser.
And I also uploaded the public key to keys.openpgp.org, but when I run
```
gpg --keyserver keys.openpgp.org --recv-keys <keyID>
```
It still gives me error:
```
gpg: keyserver.ubuntu.com, keys.openpgp.org and pgp.mit.edu receive failed: Network is unreachable
```
from browser.
Is that due to Firewall or name resolution?
Could you please take a look? Thank you!