When working behind corporate firewalls or restricted networks, you'll often encounter blocked ports - especially port 11371 used by GPG keyservers. The standard command fails:

gpg --keyserver keyserver.ubuntu.com --recv-keys 0A5174AF

This typically results in connection timeout errors or "no route to host" messages.

Many keyservers now support HTTP/HTTPS on standard ports (80/443) which are rarely blocked:

gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 0A5174AF
gpg --keyserver hkps://keyserver.ubuntu.com:443 --recv-keys 0A5174AF

When all ports are blocked, manually download the key:

# Using curl through corporate proxy if needed
curl -x http://proxy.company.com:8080 -L "https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x0A5174AF" > pubkey.asc

# Then import
gpg --import pubkey.asc

For teams, store keys in version control:

# Clone repository containing keys
git clone https://github.com/yourorg/gpg-keys.git

# Import all keys
gpg --import gpg-keys/*.asc

If you have Tor installed:

gpg --keyserver hkp://jirk5u4osbsr34t5.onion --recv-keys 0A5174AF

Always verify fingerprints after import:

gpg --fingerprint 0A5174AF

Cross-check the output with official project documentation or trusted sources.

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When working behind corporate firewalls or restricted networks, you'll often encounter this error:

$ gpg --keyserver keyserver.ubuntu.com --recv-keys 0A5174AF
gpg: keyserver receive failed: Connection timed out

This happens because most keyservers use port 11371 (HKP protocol), which is frequently blocked by network administrators.

1. Using Port 80/443 via HTTP Keyserver

Some keyservers support HTTP(S) on standard web ports:

gpg --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 0A5174AF
gpg --keyserver hkps://keyserver.ubuntu.com:443 --recv-keys 0A5174AF

2. Manual Key Import via Web Interface

Many keyservers provide web interfaces:

1. Visit https://keyserver.ubuntu.com
2. Search for your key ID (0A5174AF in our example)
3. Download the ASCII armored version
4. Import locally: gpg --import downloaded_key.asc

3. Using Alternative Protocols

# LDAP protocol (port 389 usually open):
gpg --keyserver ldap://keyserver.pgp.com --recv-keys 0A5174AF

Proxy Configuration

If you have HTTP proxy access:

gpg --keyserver-options http-proxy=http://proxy.example.com:3128 \
    --keyserver hkp://keyserver.ubuntu.com --recv-keys 0A5174AF

Key Mirroring via Tor

For extreme firewall restrictions:

sudo apt install torsocks
torsocks gpg --keyserver hkp://jirk5u4osbsr34t5.onion --recv-keys 0A5174AF

Always verify the fingerprint after importing:

gpg --fingerprint 0A5174AF

For repeated use, configure your ~/.gnupg/gpg.conf:

keyserver hkps://keyserver.ubuntu.com:443
keyserver-options auto-key-retrieve
keyserver-options http-proxy=http://proxy.example.com:3128