[Ilugc] Neighbour table overflow
- From: rsubr@xxxxxxxxxxxxxxxxxxxxxxxx (Raja Subramanian)
- Date: Sat Jun 26 21:22:37 2004
R Deepak wrote:
On Friday 25 June 2004 11:26, babu jayapaul wrote:
and Iam using the following command to share the
Internet to more than 100 users.
iptables -n nat -A POSTROUTING -o eth0 -J MASQUERADE
for the last 1 week i found the error message
"NET: 89 messages suppressed."
"Neighbour table overflow"
displaying repeatedly and the net is not shared. and
iam able to ping ping the local lan
There could be 2-3 different reasons. But the most likely one is some
virus affected windows machine (among those 100's) that is doing a
portscan or a ping sweep.
Just to be on the safe side, do not allow unrestricted access to the
internet (esp. from windows machines). Set up a -
1. a dns cache (bind).
2. a web proxy (squid).
3. open only pop/smtp ports to your mail server. Better yet, setup
a local mail server that will proxy your email.
4. you can enable yahoo messenger, MSN, ICQ, etc selectively.
5. specifically enable other traffic like outgoing ssh, etc.
6. disallow all other traffic.
This setup will effectively block internet worms and other evils from
spreading out from your network.
Btw, it's wise not to mention your public IP address on mailing lists.
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