Thanks for all the info. Problem fixed. Many thanks !!!
When traffic is being forwarded through your router it traverses
pre-routing,forward,postrouting chains.
When traffic is being used by a local process on the router it
traverses, pre-routing,input,output,postrouting chains.
I think its best to place any blacklist rules in the pre-routing chain
instead of input.
Cheers
--
Craig Steadman RHCE,MCSA,CCNA
Hello,
Could somebody please explain the 'iptables -A INPUT -eth0 -m
state --state NEW -j DROP' a bit more for me ? I understand that it won't
allow any outside initiated inbound connections into a network. However
occasionally if I'm doing a tcpdump we see things like:
21:04:48.935367 IP 82.29.180.221.15378 > 213.17.40.204.4154: R 0:0(0) ack 1
win 0
21:04:48.935447 IP 82.29.180.221.15378 > 213.17.40.204.4154: R 0:0(0) ack 1
win 0
21:04:48.935455 IP 82.29.180.221.15378 > 213.17.40.204.4154: R 0:0(0) ack 1
win 0
21:04:48.935537 IP 82.29.180.221.15378 > 213.17.40.204.4154: R 0:0(0) ack 1
win 0
21:04:48.935545 IP 82.29.180.221.15378 > 213.17.40.204.4154: R 0:0(0) ack 1
win 0
21:04:48.935629 IP 82.29.180.221.15378 > 213.17.40.204.4154: R 0:0(0) ack 1
win 0
21:04:48.935637 IP 82.29.180.221.15378 > 213.17.40.204.4154: R 0:0(0) ack 1
win 0
21:04:48.935812 IP 82.29.180.221.15378 > 213.17.40.204.4154: R 0:0(0) ack 1
win 0
21:04:48.935821 IP 82.29.180.221.15378 > 213.17.40.204.4154: R 0:0(0) ack 1
win 0
21:04:48.936045 IP 82.29.180.221.15378 > 213.17.40.204.4154: R 0:0(0) ack 1
win 0
21:04:48.936053 IP 82.29.180.221.15378 > 213.17.40.204.4154: R 0:0(0) ack 1
win 0
21:04:48.936153 IP 82.29.180.221.15378 > 213.17.40.204.4154: R 0:0(0) ack 1
win 0
What is that and shouldn't it be dropped ? Or is the : R 0:0(0) ack 1 win 0
part of it a already establish connection ? Although that's one of our IP's
it's not active on our network.
Any ideas / advice would be greatly appreciated !
Regards
Sylvan
