diff --git a/PPPOE_management.md b/PPPOE_management.md
index f4c268b..d01479d 100644
--- a/PPPOE_management.md
+++ b/PPPOE_management.md
@@ -349,6 +349,22 @@ As you can see there are 3 other PPPoE servers in the network, and they are all
 If you see message about "PCIe bandwidth, limited" this means your slot is likely have limited lanes and cannot reach full capacity. In case of X520 cards, this means about 15Gbit total bandwidth limit (in+out).
 Try to change slot or make sure riser have support for all PCIe lanes.
 
+## Misc tuning
+
+### Neighbour table overflow
+
+If you see in dmesg:
+```
+[  803.123253] neighbour: arp_cache: neighbor table overflow!
+```
+Apply following tuning:
+```
+echo 2560 > /proc/sys/net/ipv4/neigh/default/gc_thresh1 
+echo 5120 > /proc/sys/net/ipv4/neigh/default/gc_thresh2
+echo 10240 > /proc/sys/net/ipv4/neigh/default/gc_thresh3
+```
+
+
 
 ### References