diff --git a/hosts/heather/astrnet.nix b/hosts/heather/astrnet.nix
index ee67848..a1e1fbe 100644
--- a/hosts/heather/astrnet.nix
+++ b/hosts/heather/astrnet.nix
@@ -49,7 +49,8 @@ in {
 
   # Heather's public firewall is disabled (the cloud SG is the WAN barrier).
   # Explicitly restrict traffic FROM AstrNet before normal Docker/host rules:
-  # BGP from the two expected neighbors, ping to this mesh ID; no transit.
+  # BGP from the two expected neighbors, bounded ICMP to our mesh/transit
+  # addresses only; no service exposure or transit.
   # Existing outbound sessions may receive established replies.
   systemd.services.astrnet-guard = {
     description = "Restrict AstrNet tunnel ingress";
@@ -69,7 +70,11 @@ in {
           iifname "wg-mic-bd8" ip saddr 10.99.0.157 tcp dport 179 accept
           iifname "wg-mic-der" ip6 saddr fd53:4023:2326:99::99 tcp dport 179 accept
           iifname "wg-mic-bd8" ip6 saddr fd53:4023:2326:99::9d tcp dport 179 accept
-          iifname { "wg-mic-der", "wg-mic-bd8" } ip daddr 10.0.0.9 icmp type echo-request accept
+          # Echo requests only from AstrNet sources, to THIS host's addresses.
+          iifname "wg-mic-der" ip saddr { 10.0.0.0/24, 10.99.0.0/22 } ip daddr { 10.0.0.9, 10.99.0.154 } icmp type echo-request accept
+          iifname "wg-mic-bd8" ip saddr { 10.0.0.0/24, 10.99.0.0/22 } ip daddr { 10.0.0.9, 10.99.0.158 } icmp type echo-request accept
+          iifname "wg-mic-der" ip6 saddr { 2a05:f480:2400:1cf7::/64, fd53:4023:2326::/48 } ip6 daddr { 2a05:f480:2400:1cf7::9, fd53:4023:2326:99::9a, fe80::2 } icmpv6 type echo-request accept
+          iifname "wg-mic-bd8" ip6 saddr { 2a05:f480:2400:1cf7::/64, fd53:4023:2326::/48 } ip6 daddr { 2a05:f480:2400:1cf7::9, fd53:4023:2326:99::9e, fe80::2 } icmpv6 type echo-request accept
           iifname { "wg-mic-der", "wg-mic-bd8" } drop
         }
         chain forward {