Chapter 15 - firewalls
Hello,
I've collected several questions. Pls help me to fins the answer.I'm usuing CentOS7
1.I've disabled the firewalld (systemctl disable firewalld systemctl stop firewalld). I've configured the iptables with the iptables CMD.It's Ok. What the different the iptables/netfilter and firewalld ? How to do it correctly ? Must firewalld be stopped not to use it together with iptables/nftables? Any compatibility between firewalld and iptables ?
2. Chapter - Distribution Default:
It's possible to find /etc/sysconfig/iptables-config and /etc/sysconfig/ip6 tables-config instead of /etc/sysconfig/iptables. Is it the same file ?
3. How to save all my settings for the iptables not to lost it after rebooting ?
There is no the "service iptable save" command! As backup It's possible to save as the iptables-save > /root/ iptables.backup and iptables-restore < /root/iptables.backup . I think it's better than nothing but how to save it correctly ?
4. What do you mean " service iptables stop" ? You mean SysV , don't you ? I think Systemd is everything. There is no iptables/iptablesd. I cannot find systemctl status iptablesd. this is no here --> "systemctl | grep iptables" Is it possible to check the status with systemctl (not iptables -L)?
5. Where can I find the logs about unsuccessful connection attempts for the iptables ? Can i find statistics/logs If the connections are established ? Must " -j LOG..." be added to all rules where I'd like to see established connections ?
6. Firewalld is compatible with nftables. When about the iptables ? Does iptables compatible with nftables ?
Regards,
Alexey
Comments
-
Pls let me know some example about the Mangle table ? When must the table be used ?
0 -
There is no "must use" tables, only common or optional configurations.
The "mangle" table is generally used for changing the packet, like changing the MTU size or the RTT. Features of the less common tables "mangle","raw" and "security" are not covered in detail in this course.
Please see "man iptables" for additional information on the tables "mangle","raw" and "security" tables.0 -
iptables and firewall-cmd are both configuration programs that can configure netfilter firewalls, they use different configuration files. Firewalld package has a monitoring service called "firewalld" that implements the configuration created by "firewall-cmd" and friends.
As for the iptables vs iptqbles -config files in /etc/sysconfig, one file describes the iptables commands to netfilter and the other configures the environment for the iptables module. iptables-config is well documeted in the file.
Sorry, missed a "service" command, it will be purged.
You can use "iptables-save" and "iptables-restore".Use the "LOG" target.
Yes, firewalld can configure iptables or nftables.
iptables is not intended to configure nftables.
nft configures nftables.
There are of course exceptions and compatibility modes to migrate configurations and commands. Migration & conversion features are out of scope for this chapter.Regards Lee
0 -
As far as I understand there are two ways how to configure the netfilter -- iptables and firewalld. Don't they interfere one with one ? What is the best way to configure netfiler - iptables ? firewalld ? it's better to add some labs about firewalld.
As for saving configurations of the netfilter which is configure with iptables, I can set iptables-save but the configuration is deleted as soon as OS is rebooted. any other way ?
As for the "LOG" target, it's additional CMD. If i got wrong and something didn't work Would it possible to find unsuccessful connection attempts ? E.g. would i found anything in my OS about attempts if "iptables -P INPUT DROP " and "iptables -P FORWARD DROP " were set ?
Thank you
0 -
firewalld is covered in some detail in LFS201, and iptables etc in LFS211 so as to avoid repetition. YOu should have taken LFS201 before LFS211 as a pre-req (or the equivalent of course).
iptables-save saves the configuration. That is where its name comes from. Iptables-restore restores it. That is why it has restore in the name. It saves the configuration in /etc AFAIK.
It might be more productive if you put perhaps a little more effort into answering questions yourself before asking on the forum, just because this is not a real time chat and it is not unusual to wait 24 hours or more to get a response. iptables does have quite a bit of stuff in it, and while it is all conceptually not hard there is just a lot of things to absorb. (which is why we hold back on it in LFS201 and do it in LFS211) It will eventually be a diminishing legacy infrastructure, but not yet.
0 -
Hello coop,
Hope everything is Ok on your side.
Have you ever read you labs ? I mean theory and practice too. For example, It is really funny to see that the NFS is tested with loopback(127.0.0.1) instead of creating a simple topology with two OS. Why cannot I answer questions here. I've lost my money pls lose your time to answer for questions. Pls be informed it's impossible to perform the most of the labs step by step due to your mistakes I suggest asking Google to understand topics how to prepare the course.I've read the LFS201. I've asked here the best practice how to do it. This course(LFS211) is theoretical which cannot be used at all in production setup.
As for the configurations , A script must be created to load the iptables-restore after rebooting an OS.
So be polite the next time before chatting here. Probably you don't know Linux is open source word
Thank you. I'm waiting for your thanks for me because i'm improving your course with my messages here!
Regards!
-1 -
sigh. You oscillate between nice and being abusive. You should read your posts before sending and think about what kind of response they are likely to inspire.
You should understand that thousands of students have taken these courses without the constant kinds of problems you are running into and asking for immediate help. Sure there are mistakes here and there and differences because there are many different Linux distributions and versions even with distributions (Centos 7 vs 8, Ubuntu 20.04 vs 18.04 vs 16.04, Debian, Fedora etc) so a little patience on your side would be appreciated. Statments like "cannot be used at all" are not likely to engender patient and friendly response. or "Pls be informed it's impossible to perform the most of the labs step by step due to your mistakes" when thousands of students have done precisely that -- successfully complete the labs and learn from them.
I am not going to engage on this further because I am not an expert much less the expert on this course. Remember the live instructor version of this course has a list price of about $3K; you cannot get that instant help in the e-learning course.
0 -
Ha-ha. relax! Checking NFS with a loopback is funny. why not ))))
I wanted to pay $3K for LFS422 but...I lose my interest. If you cannot create a good lab for so easy topics how can...regards!
0
Categories
- All Categories
- 167 LFX Mentorship
- 219 LFX Mentorship: Linux Kernel
- 795 Linux Foundation IT Professional Programs
- 355 Cloud Engineer IT Professional Program
- 179 Advanced Cloud Engineer IT Professional Program
- 82 DevOps Engineer IT Professional Program
- 127 Cloud Native Developer IT Professional Program
- 112 Express Training Courses
- 112 Express Courses - Discussion Forum
- 6.2K Training Courses
- 48 LFC110 Class Forum - Discontinued
- 17 LFC131 Class Forum
- 35 LFD102 Class Forum
- 227 LFD103 Class Forum
- 14 LFD110 Class Forum
- 39 LFD121 Class Forum
- 15 LFD133 Class Forum
- 7 LFD134 Class Forum
- 17 LFD137 Class Forum
- 63 LFD201 Class Forum
- 3 LFD210 Class Forum
- 5 LFD210-CN Class Forum
- 2 LFD213 Class Forum - Discontinued
- 128 LFD232 Class Forum - Discontinued
- 1 LFD233 Class Forum
- 2 LFD237 Class Forum
- 23 LFD254 Class Forum
- 697 LFD259 Class Forum
- 109 LFD272 Class Forum
- 3 LFD272-JP クラス フォーラム
- 10 LFD273 Class Forum
- 152 LFS101 Class Forum
- 1 LFS111 Class Forum
- 1 LFS112 Class Forum
- 1 LFS116 Class Forum
- 1 LFS118 Class Forum
- LFS120 Class Forum
- 7 LFS142 Class Forum
- 7 LFS144 Class Forum
- 3 LFS145 Class Forum
- 1 LFS146 Class Forum
- 3 LFS147 Class Forum
- 1 LFS148 Class Forum
- 15 LFS151 Class Forum
- 1 LFS157 Class Forum
- 33 LFS158 Class Forum
- 8 LFS162 Class Forum
- 1 LFS166 Class Forum
- 1 LFS167 Class Forum
- 3 LFS170 Class Forum
- 2 LFS171 Class Forum
- 1 LFS178 Class Forum
- 1 LFS180 Class Forum
- 1 LFS182 Class Forum
- 1 LFS183 Class Forum
- 29 LFS200 Class Forum
- 736 LFS201 Class Forum - Discontinued
- 2 LFS201-JP クラス フォーラム
- 14 LFS203 Class Forum
- 102 LFS207 Class Forum
- 1 LFS207-DE-Klassenforum
- 1 LFS207-JP クラス フォーラム
- 301 LFS211 Class Forum
- 55 LFS216 Class Forum
- 48 LFS241 Class Forum
- 42 LFS242 Class Forum
- 37 LFS243 Class Forum
- 15 LFS244 Class Forum
- LFS245 Class Forum
- LFS246 Class Forum
- 50 LFS250 Class Forum
- 1 LFS250-JP クラス フォーラム
- LFS251 Class Forum
- 154 LFS253 Class Forum
- LFS254 Class Forum
- LFS255 Class Forum
- 5 LFS256 Class Forum
- 1 LFS257 Class Forum
- 1.3K LFS258 Class Forum
- 10 LFS258-JP クラス フォーラム
- 111 LFS260 Class Forum
- 159 LFS261 Class Forum
- 41 LFS262 Class Forum
- 82 LFS263 Class Forum - Discontinued
- 15 LFS264 Class Forum - Discontinued
- 11 LFS266 Class Forum - Discontinued
- 20 LFS267 Class Forum
- 24 LFS268 Class Forum
- 29 LFS269 Class Forum
- 1 LFS270 Class Forum
- 199 LFS272 Class Forum
- 1 LFS272-JP クラス フォーラム
- LFS274 Class Forum
- 3 LFS281 Class Forum
- 9 LFW111 Class Forum
- 260 LFW211 Class Forum
- 182 LFW212 Class Forum
- 13 SKF100 Class Forum
- 1 SKF200 Class Forum
- 1 SKF201 Class Forum
- 782 Hardware
- 198 Drivers
- 68 I/O Devices
- 37 Monitors
- 96 Multimedia
- 174 Networking
- 91 Printers & Scanners
- 83 Storage
- 743 Linux Distributions
- 80 Debian
- 67 Fedora
- 15 Linux Mint
- 13 Mageia
- 23 openSUSE
- 143 Red Hat Enterprise
- 31 Slackware
- 13 SUSE Enterprise
- 348 Ubuntu
- 461 Linux System Administration
- 39 Cloud Computing
- 70 Command Line/Scripting
- Github systems admin projects
- 90 Linux Security
- 77 Network Management
- 101 System Management
- 46 Web Management
- 64 Mobile Computing
- 17 Android
- 34 Development
- 1.2K New to Linux
- 1K Getting Started with Linux
- 371 Off Topic
- 114 Introductions
- 174 Small Talk
- 19 Study Material
- 507 Programming and Development
- 285 Kernel Development
- 204 Software Development
- 1.8K Software
- 211 Applications
- 180 Command Line
- 3 Compiling/Installing
- 405 Games
- 309 Installation
- 97 All In Program
- 97 All In Forum
Upcoming Training
-
August 20, 2018
Kubernetes Administration (LFS458)
-
August 20, 2018
Linux System Administration (LFS301)
-
August 27, 2018
Open Source Virtualization (LFS462)
-
August 27, 2018
Linux Kernel Debugging and Security (LFD440)