diff --git a/nodes.md b/nodes.md
index 4847078..3b04789 100644
--- a/nodes.md
+++ b/nodes.md
@@ -2,7 +2,9 @@ Endpoint port:
 - If `424242xxxx`: `2xxxx`
 - If not: [use this](https://dn42.m724.eu/calculator)
 
-Use link-local to peer, pingables are for pinging
+Use link-local to peer, pingables are for pinging \
+Prefix hostname with `ipv4.` to force IPv4 \
+**Ping both v4 and v6! If IPv4 is better, use it**
 
 ### Amsterdam, Netherlands
 - `nl1.420129.xyz` 100 Mbps (v6)