What is the best way to turn off the iptables

[lina <lina.lastname@gmail.com>]

Hi,

What is the best way to turn off the iptables?

or come back to its default settings. Flush my current one.

Since I tried to configure the iptables, I have encountered the
following problems:

1] I can't access the cups and some other ports I opened in localhost.

I comment the line 5 still not work.

# Allow all loopback (lo0) traffic and drop all traffic to 127/8 that
doesn't use lo0
  4 -A INPUT -i lo -j ACCEPT
  5 #-A INPUT ! -i lo -d 127.0.0.0/8 -j REJECT

2] The shutdown process in decades long. I mean it used to be fast to
shutdown, now need wait ~3 mins

BTW, how to check the time of booting and shutting down?

3] My syslog is flooding with similar information (kernel: [
436.954509] --log-prefixIN=eth0 OUT=
MAC=ff:ff:ff:ff:ff:ff:00:30:67:08:28:b3:08:00 SRC=172.21.50.212
DST=172.21.51.255 LEN=78 TOS=0x00 PREC=0x00 TTL=128 ID=58729 PROTO=UDP
SPT=137 DPT=137 LEN=58 ).

google showed me it's possible to put the log not in syslog.

4] Are there someone willing to sharing some iptables template, a bit
mature one with explaination.

Thanks with best regards,

P.S. The current one I used ( mainly adopted from
http://wiki.debian.org/iptables ), Here it is:

  1 *filter
  2
  3 # Allow all loopback (lo0) traffic and drop all traffic to 127/8
that doesn't use lo0
  4 -A INPUT -i lo -j ACCEPT
  5 #-A INPUT ! -i lo -d 127.0.0.0/8 -j REJECT
  6
  7 # Accept all established inbound connections
  8 -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
  9
 10 # Allows all outbound traffic
 11 # You could modify this to only allow certain traffic
 12 -A OUTPUT -j ACCEPT
 13
 14 # Allow HTTP and HTTPS connections from anywhere (the normal ports
for websites)
 15 -A INPUT -p tcp --dport 80 -j ACCEPT
 16 -A INPUT -p tcp --dport 443 -j ACCEPT
 17
 18 # Allow SSH connections
 19 #-A INPUT -p tcp --dport 22 -j ACCEPT
 20 -A INPUT -p tcp -m state --state NEW --dport 22 -j ACCEPT
 21
 22 # Allow ping
 23 -A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT
 24
 25 # log iptables denied calls (access via 'dmesg' command)
 26 -A INPUT -m limit --limit 5/min -j LOG --log-prefix "iptables
denied: " --log-level warning
 27
 28 # Reject all other inbound - default deny unless explicitly allowed policy:
 29 -A INPUT -j REJECT
 30 -A FORWARD -j REJECT
 31
 32 COMMIT