When I log the length of a echo-request packet,
iptables -A OUTPUT -p icmp -m icmp --icmp-type 8 -j LOG
I saw the length was LEN=84, but in wireshark, the captured packet size was 0x60, why does it differ?
Exercise:
Protection of WEB and DNS servers using the context-free rules for packet filtering:
- Protect your WEB-server, so that would be for him can be accessed by browsers, and could go to dns.
- Protect your primary DNS-server so that it could be to contact clients and secondary servers.
- Allow ICMP ping to / from your site (s).
- the rest is declined.
My solution that:
Code:
CentOS 4.x
I've got several old CentOS 4.x systems and have configured iptables to allow ICMP traffic.
I read that certain types¹ of ICMP packets can be harmful. Questions:
Which ones and why?
How should I layout an iptables ruleset to handle each type of ICMP packet?
Should I rate-limit any of these types of ICMP packets? And how?
[¹] The types I read about: Redirect (5), Timestamp (13) and Address Mask Request (17).
I have the following rule,which i believe will restrict icmp packets to 1/s.
For the following iptables rule:
iptables -A INPUT -p icmp -m icmp --icmp-type 255 -j ACCEPT
I am not sure what the point of "-m" is given that "-p" is already present. Does it serve any purpose in this case?
I am setuping my server and I must disable the ping requests for everyone except me and a list of hosts (aaa.bbb.ccc.ddd).
I am using the tool ufw, on ubuntu server, I read that I have to comment those lines:
ok icmp codes
-A ufw-before-input -p icmp --icmp-type destination-unreachable -j ACCEPT
-A ufw-before-input -p icmp --icmp-type source-quench -j ACCEPT
-A ufw-before-input -p icmp --
I am new to iptables and learning them from here
I have questions about the following:
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT This is the rule that does most of the work, and again we are adding
(-A) it to the INPUT chain. Here we're using the -m switch to load a
module (state).
Hello all. I'd welcome some advice here.
I acquired a new home wireless router a few days ago.
Having configured it, I set it up to email me its logs periodically.
Here is the first:
<Log Starts>
Oct 19 21:52:24 | Drop PING request from WAN (ip:99.195.134.66).