You just need to do the drop on all other port 25 outbound, also the NEW,ESTABLISHED thing doesn't really help you here as you want all types to work.
I'd also suggest you leave off the -o eth0 too as you are trying to prevent outbound traffic in general, regardless of it's routing.
edit: According to the iptables help, you can actually specify negation - ie:
Never tried this myself though so YMMV
My server is running on a port 16386, in the case when this port is blocked by some other application ( anti virus etc. ) or firewall then how do i know it's block? Is bind will return any specific error in this case.
I have to know is it blocked or not? (2 Replies)
May I know what is the TCP/UCP port range for any default AIX NFS? Based on rpcinfo -p, I got the following output:
program vers proto port service
100000 4 udp 111 portmapper
100000 3 udp 111 portmapper
100000 2 udp 111 portmapper
100000 4 ... (4 Replies)
Hi To All,
I want to Route my web application to Mysql Database through a proxy server.so for this which approach should i use
1)iptables
2)squid
if Iptables how can i make this worked .this is the ip network i'm having
web application---------Proxy server-----------------Mysql Database... (0 Replies)
Hello
I'm beginner in the linux scripting and i would like to get help. I want to create a script that can block one or more Port even see all the TCP port. The ports must be blocked even when starting my machine.
Of course requires a second script which will allow the ports that you want to... (0 Replies)
Hi Guys,
Please could you tell me if it is possible to have a single rule/filter to allow a certain port range instead of a separate rule for each port?
I'm sure it must be possible but I am unable to find the syntax.
Thanks
Chris (4 Replies)
In my Linux system ephemeral port range is showing different ranges as follows
$ cat /proc/sys/net/ipv4/ip_local_port_range
32768 61000
cat /etc/sysctl.conf | grep net.ipv4.ip_local_port_range
net.ipv4.ip_local_port_range = 9000 65500
Which will be the effective ephemeral port... (5 Replies)
I'll start with I'm not an AIX expert, I inherited a lot of AIX servers to maintain.
My problem is on AIX 7.1 TL4 SP4 environments. I'm running named as a DNS forwarder only to internal DNS servers.
These AIX servers have a customized UDP ephemeral port range to avoid conflicting with the... (0 Replies)
hi,
i would like to create a bash script that check which port in my Linux server are closed (not in use) from a specific range, port range (3000-3010).
the print output need to be only 1 port, and it will be nice if the output will be saved as a variable or in same file.
my code is:
... (2 Replies)
Discussion started by: yossi
2 Replies
LEARN ABOUT X11R4
tc-fw
Firewall mark classifier in tc(8) Linux Firewall mark classifier in tc(8)NAME
fw - fwmark traffic control filter
SYNOPSIS
tc filter ... fw [ classid CLASSID ] [ action ACTION_SPEC ]
DESCRIPTION
the fw filter allows to classify packets based on a previously set fwmark by iptables. If it is identical to the filter's handle, the fil-
ter matches. iptables allows to mark single packets with the MARK target, or whole connections using CONNMARK. The benefit of using this
filter instead of doing the heavy-lifting with tc itself is that on one hand it might be convenient to keep packet filtering and classifi-
cation in one place, possibly having to match a packet just once, and on the other users familiar with iptables but not tc will have a less
hard time adding QoS to their setups.
OPTIONS
classid CLASSID
Push matching packets to the class identified by CLASSID.
action ACTION_SPEC
Apply an action from the generic actions framework on matching packets.
EXAMPLES
Take e.g. the following tc filter statement:
tc filter add ... handle 6 fw classid 1:1
will match if the packet's fwmark value is 6. This is a sample iptables statement marking packets coming in on eth0:
iptables -t mangle -A PREROUTING -i eth0 -j MARK --set-mark 6
SEE ALSO tc(8), iptables(8), iptables-extensions(8)iproute2 21 Oct 2015 Firewall mark classifier in tc(8)