Hongwei Li wrote:
Hongwei Li wrote:
Hongwei Li wrote:
I have a question about iptables in fc5. I have iptables 1.3.5-1.2
installed.
By default, the iptables has a line
-A RH-Firewall-1-INPUT -p icmp --icmp-type any -j ACCEPT
... and
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
I try to add the port 2049 for our lan nfs by adding aline before the
above
reject line:
-A RH-Firewall-1-INPUT -s 128.252.85.0/255.255.255.0 -m state --state NEW
-m
tcp -p tcp --dport 2049 -j ACCEPT
That rule will only match the initial packet of the stream. You will
also need to match states ESTABLISHED and RELATED:
-A RH-Firewall-1-INPUT -s 128.252.85.0/255.255.255.0 -m state --state
NEW,ESTABLISHED,RELATED -p tcp --dport 2049 -j ACCEPT
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
and restart iptables. But my other linux boxes cannot mount the exported
folder. If I stop the iptable, then they can mount it. I tried to open
several other ports: 137, 139, etc. But as long as the last line is there,
it
always failed. If I comment out the last line, then nfs works.
What is "icmp-host-prohibited"
Just what it says. You are prohibited from accessing this host.
I don't know if the output of tcpdump -nn helps or not:
...
16:02:40.803697 IP 128.252.85.35.22 > 128.252.85.103.2167: P
<snip />
oooh :( SSH makes alot of noise. Not too useful this way.
Here is iptables-save output:
# Generated by iptables-save v1.3.5 on Mon May 15 15:59:18 2006
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:RH-Firewall-1-INPUT - [0:0]
:okay - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT
-A OUTPUT -s 127.0.0.1 -j ACCEPT
-A OUTPUT -s 128.252.85.35 -j ACCEPT
-A RH-Firewall-1-INPUT -s 127.0.0.1 -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -s 128.252.85.35 -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -p icmp -m icmp --icmp-type any -j ACCEPT
-A RH-Firewall-1-INPUT -p ipv6-crypt -j ACCEPT
-A RH-Firewall-1-INPUT -p ipv6-auth -j ACCEPT
-A RH-Firewall-1-INPUT -d 224.0.0.251 -p udp -m udp --dport 5353 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp -m udp --dport 631 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m tcp --dport 631 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW,RELATED,ESTABLISHED -m tcp
--dport 21 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW,RELATED,ESTABLISHED -m tcp
--dport 22 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW,RELATED,ESTABLISHED -m tcp
--dport 25 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW,RELATED,ESTABLISHED -m tcp
--dport 80 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp -m state --state NEW,RELATED,ESTABLISHED -m udp
--dport 137 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp -m state --state NEW,RELATED,ESTABLISHED -m udp
--dport 139 -j ACCEPT
-A RH-Firewall-1-INPUT -s 128.252.85.0/255.255.255.0 -p tcp -m state --state
NEW,RELATED,ESTABLISHED -m tcp --dport 2049 -j ACCEPT
-A RH-Firewall-1-INPUT -s 128.252.85.0/255.255.255.0 -p udp -m state --state
NEW,RELATED,ESTABLISHED -m udp --dport 2049 -j ACCEPT
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
-A okay -p tcp -m tcp --tcp-flags SYN,RST,ACK SYN -j ACCEPT
-A okay -p tcp -m state --state RELATED,ESTABLISHED -j ACCEPT
COMMIT
# Completed on Mon May 15 15:59:18 2006
I just added udp for nfs port, but still the same problem.
Ok. Just looked through your "iptables-save". There is some
duplication but nothing that I can see that is wrong.
Since you are hitting the REJECT you are not matching a previous rule.
From what I can see, the rules must be failing because
a) source address/mask isn't what is being used;
b) port number is not the one being used.
If you use "tcpdump -nn port ! ssh" while you try using nfs you should
receive something more useable.
