I've been using tcpdump to try and troubleshoot the packets. Both the source and destination of the packet are localhost. I noticed that by changing the OUTPUT (and enabling "NAT_LOCAL" in my linux 2.4.25 kernel), tcpdump is fooled into thinking the packet is headed to port 5300 but I think by that point the packet has passed the application layer and bind doesn't see the packet.
Also, I have the filter table accepting EVERYTHING.
# iptables -L -vn
Chain INPUT (policy ACCEPT 18907 packets, 1521K bytes)
pkts bytes target prot opt in out source destination
Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
Chain OUTPUT (policy ACCEPT 18208 packets, 2540K bytes)
pkts bytes target prot opt in out source destination
#
On Mar 23, 2004, at 1:10 PM, Ben Yerushalmi wrote:
Hi,
I'm trying to redirect traffic on my DNS server. I have bind listening on port 5300 (UDP) instead of 53. I've got it working from the internal network but seem to have problem on redirecting localhost traffic. I've tried changing both PREROUTING and OUTPUT chains in the nat table but it doesn't seem to help.
iptables -A PREROUTING -t nat -p udp -i lo --dport domain -j REDIRECT --to-ports 5300
and
iptables -A OUTPUT -t nat -p udp -d localhost --dport domain -j REDIRECT --to-ports 5300
Anyone have luck doing this? What am I missing?
Thanks, Ben
