Syncthing Relay Server IPs

https://github.com/elliotwutingfeng/SyncthingRelayServerIPs/blob/main/ips.txt?raw=1

Address list per script

Fetch the list and import it into an address list called blocklist:

/tool fetch url="https://github.com/elliotwutingfeng/SyncthingRelayServerIPs/blob/main/ips.txt?raw=1" dst-path=blocklist.rsc
/import blocklist.rsc

If the list is a plain text file with one address or CIDR per line, convert it first:

/tool fetch url="https://github.com/elliotwutingfeng/SyncthingRelayServerIPs/blob/main/ips.txt?raw=1" dst-path=blocklist.txt
:foreach line in=[/file get blocklist.txt contents] do={
  /ip firewall address-list add list=blocklist address=$line comment="Syncthing Relay Server IPs"
}

Use the list in the firewall

/ip firewall filter add chain=forward src-address-list=blocklist action=drop comment="Syncthing Relay Server IPs"
/ip firewall filter add chain=forward dst-address-list=blocklist action=drop comment="Syncthing Relay Server IPs"

Schedule the fetch with /system scheduler to keep the list current. Very large lists consume RAM, so check the available memory of your device first.

MikroTik RouterOS documentation

banIP (recommended)

1. Install the package: opkg update && opkg install banip luci-app-banip
2. Open LuCI → Services → banIP → Feeds and add a custom feed with the URL below.
3. Enable the feed and click Save & Apply.

https://github.com/elliotwutingfeng/SyncthingRelayServerIPs/blob/main/ips.txt?raw=1

Manual with nftables

wget -qO /tmp/blocklist.txt "https://github.com/elliotwutingfeng/SyncthingRelayServerIPs/blob/main/ips.txt?raw=1"
nft add set inet fw4 blocklist { type ipv4_addr; flags interval; }
nft -f - <<EOF
$(awk '!/^[#;]/ && NF {print "add element inet fw4 blocklist { " $1 " }"}' /tmp/blocklist.txt)
EOF
nft add rule inet fw4 forward ip saddr @blocklist drop

OpenWrt (banIP) documentation

ipset create blocklist hash:net -exist
curl -fsSL "https://github.com/elliotwutingfeng/SyncthingRelayServerIPs/blob/main/ips.txt?raw=1" | grep -Eo '^[0-9]{1,3}(.[0-9]{1,3}){3}(/[0-9]{1,2})?' | 
  while read -r net; do ipset add blocklist "$net" -exist; done
iptables -I INPUT  -m set --match-set blocklist src -j DROP
iptables -I FORWARD -m set --match-set blocklist src -j DROP

Persist the set and re-run the download from cron to keep it current:

ipset save blocklist -f /etc/ipset.blocklist
# /etc/cron.daily/blocklist

iptables / ipset documentation

Add the list as an ipset in /etc/firehol/firehol.conf:

ipset4 create blocklist hash:net
ipset4 addfile blocklist "https://github.com/elliotwutingfeng/SyncthingRelayServerIPs/blob/main/ips.txt?raw=1"
blacklist4 full inface any src ipset:blocklist

Reload with firehol try and confirm before making it permanent.

FireHOL documentation

1. Go to Firewall → Aliases and click +.
2. Choose type URL Table (IPs), set a refresh interval (for example 1 day) and paste the URL below.
3. Save and apply, then use the alias as source in a block rule under Firewall → Rules.

https://github.com/elliotwutingfeng/SyncthingRelayServerIPs/blob/main/ips.txt?raw=1

OPNsense (Firewall-Aliase) documentation

1. Go to Firewall → pfBlockerNG → IP → IPv4 and click Add.
2. Paste the URL below as source, set State to ON and pick the action (Deny Both is the usual choice).
3. Save, then run Update → Force Reload → IP.

https://github.com/elliotwutingfeng/SyncthingRelayServerIPs/blob/main/ips.txt?raw=1

pfSense (pfBlockerNG IP) documentation

curl -fsSL "https://github.com/elliotwutingfeng/SyncthingRelayServerIPs/blob/main/ips.txt?raw=1" -o /var/lib/suricata/data/blocklist.txt

Reference the file from a rule using a dataset:

alert ip [!$HOME_NET] any -> $HOME_NET any (msg:"Syncthing Relay Server IPs match"; 
  ip.src; dataset:isset,blocklist, type string, load blocklist.txt; sid:1000001;)

Suricata / IDS documentation