diff --git a/files/interfaces-troisdorf5 b/files/interfaces-troisdorf5
index 3afaedd..6a296de 100644
--- a/files/interfaces-troisdorf5
+++ b/files/interfaces-troisdorf5
@@ -36,7 +36,6 @@ iface gre-bb-a.ak.ber inet static
         pre-up ip tunnel add $IFACE mode gre local 138.201.54.123 remote 185.66.195.0 ttl 255
         post-up iptables -t nat -A POSTROUTING -o $IFACE -j SNAT --to-source 185.66.193.105
         post-up iptables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o $IFACE -j TCPMSS --set-mss 1312
-        post-up ip6tables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o $IFACE -j TCPMSS --set-mss 1312
         post-up ip link set $IFACE mtu 1400
         post-down iptables -t nat -D POSTROUTING -o $IFACE -j SNAT --to-source 185.66.193.105
         post-down ip tunnel del $IFACE
@@ -44,6 +43,7 @@ iface gre-bb-a.ak.ber inet static
 iface gre-bb-a.ak.ber inet6 static
         address 2a03:2260:0:155::2/64
         netmask 64
+        post-up ip6tables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o $IFACE -j TCPMSS --set-mss 1312
 
 # Berlin Router B
 auto gre-bb-b.ak.ber
@@ -53,7 +53,6 @@ iface gre-bb-b.ak.ber inet static
         pre-up ip tunnel add $IFACE mode gre local 138.201.54.123 remote 185.66.195.1 ttl 255
         post-up iptables -t nat -A POSTROUTING -o $IFACE -j SNAT --to-source 185.66.193.105
         post-up iptables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o $IFACE -j TCPMSS --set-mss 1312
-        post-up ip6tables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o $IFACE -j TCPMSS --set-mss 1312
         post-up ip link set $IFACE mtu 1400
         post-down iptables -t nat -D POSTROUTING -o $IFACE -j SNAT --to-source 185.66.193.105
         post-down ip tunnel del $IFACE
@@ -61,6 +60,7 @@ iface gre-bb-b.ak.ber inet static
 iface gre-bb-b.ak.ber inet6 static
         address 2a03:2260:0:156::2/64
         netmask 64
+        post-up ip6tables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o $IFACE -j TCPMSS --set-mss 1312
 
 
 # Duesseldorf Router A
@@ -71,7 +71,6 @@ iface gre-bb-a.ix.dus inet static
         pre-up ip tunnel add $IFACE mode gre local 138.201.54.123 remote 185.66.193.0 ttl 255
         post-up iptables -t nat -A POSTROUTING -o $IFACE -j SNAT --to-source 185.66.193.105
         post-up iptables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o $IFACE -j TCPMSS --set-mss 1312
-        post-up ip6tables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o $IFACE -j TCPMSS --set-mss 1312
         post-up ip link set $IFACE mtu 1400
         post-down iptables -t nat -D POSTROUTING -o $IFACE -j SNAT --to-source 185.66.193.105
         post-down ip tunnel del $IFACE
@@ -79,6 +78,7 @@ iface gre-bb-a.ix.dus inet static
 iface gre-bb-a.ix.dus inet6 static
         address 2a03:2260:0:157::2/64
         netmask 64
+        post-up ip6tables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o $IFACE -j TCPMSS --set-mss 1312
 
 
 # Duesseldorf Router B
@@ -89,7 +89,6 @@ iface gre-bb-b.ix.dus inet static
         pre-up ip tunnel add $IFACE mode gre local 138.201.54.123 remote 185.66.193.1 ttl 255
         post-up iptables -t nat -A POSTROUTING -o $IFACE -j SNAT --to-source 185.66.193.105
         post-up iptables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o $IFACE -j TCPMSS --set-mss 1312
-        post-up ip6tables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o $IFACE -j TCPMSS --set-mss 1312
         post-up ip link set $IFACE mtu 1400
         post-down iptables -t nat -D POSTROUTING -o $IFACE -j SNAT --to-source 185.66.193.105
         post-down ip tunnel del $IFACE
@@ -97,3 +96,4 @@ iface gre-bb-b.ix.dus inet static
 iface gre-bb-b.ix.dus inet6 static
         address 2a03:2260:0:158::2/64
         netmask 64
+        post-up ip6tables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o $IFACE -j TCPMSS --set-mss 1312