Firewall (Openbsd PF)
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TCPDUMP Caution
TCPDUMP q Refer to book ”Open Source Network Administration” m Online sample chapter: http://www.phptr.com/articles/article.asp?p=170902&seqNum=4 q Some tools are not based directly on the data being transmitted on a network, but information related to that data. m For example, network bandwidth values m System logs on network equipment q Sometimes needs to examine the packets themselves. m Diagnose some particularly tricky network problems q Widely used open source tool for directly analyzing packets: tcpdump m http://www.tcpdump.org/ Network Analyzer 1-1 Caution q Before you use tcpdump or other analyzer: m Will be able to see some private data m Consult/research Legal implication first m Respect the privacy of other users Network Analyzer 1-2 1 What Tcpdump can do for you q View the entire data portion of an Ethernet frame or other link layer protocol m An IP packet m An ARP packet m Or any protocol at a higher layer than Ethernet. q Very useful m Tcpdump is to a network administrator like a microscope to a biologist. m Give a very clear picture of a specific part of your network m Can be used when the problem is simply that something is not working properly. Network Analyzer 1-3 What tcpdump can do for you? q Case1 : Web browser can not load pages from a server – it hangs. m Problem with client? Server? Or between? m Run tcpdump while loading • Watch every stage to see the following – DNS query – HTTP request to server – Server respond q Case 2: help debug denial of service attacks. -
The Title Title: Subtitle March 2007
sub title The Title Title: Subtitle March 2007 Copyright c 2006-2007 BSD Certification Group, Inc. Permission to use, copy, modify, and distribute this documentation for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. THE DOCUMENTATION IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS DOCUMENTATION INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CON- SEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEG- LIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS DOCUMENTATION. NetBSD and pkgsrc are registered trademarks of the NetBSD Foundation, Inc. FreeBSD is a registered trademark of the FreeBSD Foundation. Contents Introduction vii 1 Installing and Upgrading the OS and Software 1 1.1 Recognize the installation program used by each operating system . 2 1.2 Recognize which commands are available for upgrading the operating system 6 1.3 Understand the difference between a pre-compiled binary and compiling from source . 8 1.4 Understand when it is preferable to install a pre-compiled binary and how to doso ...................................... 9 1.5 Recognize the available methods for compiling a customized binary . 10 1.6 Determine what software is installed on a system . 11 1.7 Determine which software requires upgrading . 12 1.8 Upgrade installed software . 12 1.9 Determine which software have outstanding security advisories . -
Active-Active Firewall Cluster Support in Openbsd
Active-Active Firewall Cluster Support in OpenBSD David Gwynne School of Information Technology and Electrical Engineering, University of Queensland Submitted for the degree of Bachelor of Information Technology COMP4000 Special Topics Industry Project February 2009 to leese, who puts up with this stuff ii Acknowledgements I would like to thank Peter Sutton for allowing me the opportunity to do this work as part of my studies at the University of Queensland. A huge thanks must go to Ryan McBride for answering all my questions about pf and pfsync in general, and for the many hours working with me on this problem and helping me test and debug the code. Thanks also go to Theo de Raadt, Claudio Jeker, Henning Brauer, and everyone else at the OpenBSD network hackathons who helped me through this. iii Abstract The OpenBSD UNIX-like operating system has developed several technologies that make it useful in the role of an IP router and packet filtering firewall. These technologies include support for several standard routing protocols such as BGP and OSPF, a high performance stateful IP packet filter called pf, shared IP address and fail-over support with CARP (Common Address Redundancy Protocol), and a protocol called pfsync for synchronisation of the firewalls state with firewalls over a network link. These technologies together allow the deployment of two or more computers to provide redundant and highly available routers on a network. However, when performing stateful filtering of the TCP protocol with pf, the routers must be configured in an active-passive configuration due to the current semantics of pfsync. -
I3: Maximizing Packet Capture Performance
I3: Maximizing Packet Capture Performance Andrew Brown Agenda • Why do captures drop packets, how can you tell? • Software considerations • Hardware considerations • Potential hardware improvements • Test configurations/parameters • Performance results Sharkfest 2014 What is a drop? • Failure to capture a packet that is part of the traffic in which you’re interested • Dropped packets tend to be the most important • Capture filter will not necessarily help Sharkfest 2014 Why do drops occur? • Applications don’t know that their data is being captured • Result: Only one chance to capture a packet • What can go wrong? Let’s look at the life of a packet Sharkfest 2014 Internal packet flow • Path of a packet from NIC to application (Linux) • Switch output queue drops • Interface drops • Kernel drops Sharkfest 2014 Identifying drops • Software reports drops • L4 indicators (TCP ACKed lost segment) • L7 indicators (app-level sequence numbers revealed by dissector) Sharkfest 2014 When is (and isn’t) it necessary to take steps to maximize capture performance? • Not typically necessary when capturing traffic of <= 1G end device • More commonly necessary when capturing uplink traffic from a TAP or SPAN port • Some sort of action is almost always necessary at 10G • Methods described aren’t always necessary • Methods focus on free solutions Sharkfest 2014 Software considerations - Windows • Quit unnecessary programs • Avoid Wireshark for capturing ˗ Saves to TEMP ˗ Additional processing for packet statistics • Uses CPU • Uses memory over time, can lead -
Mellanox OFED for Freebsd for Connectx-4 and Above Adapter Cards User Manual
Mellanox OFED for FreeBSD for ConnectX-4 and above Adapter Cards User Manual Rev 3.5.2 www.mellanox.com Mellanox Technologies NOTE: THIS HARDWARE, SOFTWARE OR TEST SUITE PRODUCT (“PRODUCT(S)”) AND ITS RELATED DOCUMENTATION ARE PROVIDED BY MELLANOX TECHNOLOGIES “AS-IS” WITH ALL FAULTS OF ANY KIND AND SOLELY FOR THE PURPOSE OF AIDING THE CUSTOMER IN TESTING APPLICATIONS THAT USE THE PRODUCTS IN DESIGNATED SOLUTIONS. THE CUSTOMER'S MANUFACTURING TEST ENVIRONMENT HAS NOT MET THE STANDARDS SET BY MELLANOX TECHNOLOGIES TO FULLY QUALIFY THE PRODUCT(S) AND/OR THE SYSTEM USING IT. THEREFORE, MELLANOX TECHNOLOGIES CANNOT AND DOES NOT GUARANTEE OR WARRANT THAT THE PRODUCTS WILL OPERATE WITH THE HIGHEST QUALITY. ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT ARE DISCLAIMED. IN NO EVENT SHALL MELLANOX BE LIABLE TO CUSTOMER OR ANY THIRD PARTIES FOR ANY DIRECT, INDIRECT, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES OF ANY KIND (INCLUDING, BUT NOT LIMITED TO, PAYMENT FOR PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY FROM THE USE OF THE PRODUCT(S) AND RELATED DOCUMENTATION EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Mellanox Technologies 350 Oakmead Parkway Suite 100 Sunnyvale, CA 94085 U.S.A. www.mellanox.com Tel: (408) 970-3400 Fax: (408) 970-3403 © Copyright 2019. Mellanox Technologies Ltd. All Rights Reserved. Mellanox®, Mellanox logo, Mellanox Open Ethernet®, LinkX®, Mellanox Spectrum®, Mellanox Virtual Modular Switch®, MetroDX®, MetroX®, MLNX-OS®, ONE SWITCH. -
Performance, Scalability on the Server Side
Performance, Scalability on the Server Side John VanDyk Presented at Des Moines Web Geeks 9/21/2009 Who is this guy? History • Apple // • Macintosh • Windows 3.1- Server 2008R2 • Digital Unix (Tru64) • Linux (primarily RHEL) • FreeBSD Systems Iʼve worked with over the years. Languages • Perl • Userland Frontier™ • Python • Java • Ruby • PHP Languages Iʼve worked with over the years (Userland Frontier™ʼs integrated language is UserTalk™) Open source developer since 2000 Perl/Python/PHP MySQL Apache Linux The LAMP stack. Time to Serve Request Number of Clients Performance vs. scalability. network in network out RAM CPU Storage These are the basic laws of physics. All bottlenecks are caused by one of these four resources. Disk-bound •To o l s •iostat •vmstat Determine if you are disk-bound by measuring throughput. vmstat (BSD) procs memory page disk faults cpu r b w avm fre flt re pi po fr sr tw0 in sy cs us sy id 0 2 0 799M 842M 27 0 0 0 12 0 23 344 2906 1549 1 1 98 3 3 0 869M 789M 5045 0 0 0 406 0 10 1311 17200 5301 12 4 84 3 5 0 923M 794M 5219 0 0 0 5178 0 27 1825 21496 6903 35 8 57 1 2 0 931M 784M 909 0 0 0 146 0 12 955 9157 3570 8 4 88 blocked plenty of RAM, idle processes no swapping CPUs A disk-bound FreeBSD machine. b = blocked for resources fr = pages freed/sec cs = context switches avm = active virtual pages in = interrupts flt = memory page faults sy = system calls per interval vmstat (RHEL5) # vmstat -S M 5 25 procs ---------memory-------- --swap- ---io--- --system- -----cpu------ r b swpd free buff cache si so bi bo in cs us sy id wa st 1 0 0 1301 194 5531 0 0 0 29 1454 2256 24 20 56 0 0 3 0 0 1257 194 5531 0 0 0 40 2087 2336 34 27 39 0 0 2 0 0 1183 194 5531 0 0 0 53 1658 2763 33 28 39 0 0 0 0 0 1344 194 5531 0 0 0 34 1807 2125 29 19 52 0 0 no blocked busy but not processes overloaded CPU in = interrupts/sec cs = context switches/sec wa = time waiting for I/O Solving disk bottlenecks • Separate spindles (logs and databases) • Get rid of atime updates! • Minimize writes • Move temp writes to /dev/shm Overview of what weʼre about to dive into. -
BSD UNIX Toolbox 1000+ Commands for Freebsd, Openbsd
76034ffirs.qxd:Toolbox 4/2/08 12:50 PM Page iii BSD UNIX® TOOLBOX 1000+ Commands for FreeBSD®, OpenBSD, and NetBSD®Power Users Christopher Negus François Caen 76034ffirs.qxd:Toolbox 4/2/08 12:50 PM Page ii 76034ffirs.qxd:Toolbox 4/2/08 12:50 PM Page i BSD UNIX® TOOLBOX 76034ffirs.qxd:Toolbox 4/2/08 12:50 PM Page ii 76034ffirs.qxd:Toolbox 4/2/08 12:50 PM Page iii BSD UNIX® TOOLBOX 1000+ Commands for FreeBSD®, OpenBSD, and NetBSD®Power Users Christopher Negus François Caen 76034ffirs.qxd:Toolbox 4/2/08 12:50 PM Page iv BSD UNIX® Toolbox: 1000+ Commands for FreeBSD®, OpenBSD, and NetBSD® Power Users Published by Wiley Publishing, Inc. 10475 Crosspoint Boulevard Indianapolis, IN 46256 www.wiley.com Copyright © 2008 by Wiley Publishing, Inc., Indianapolis, Indiana Published simultaneously in Canada ISBN: 978-0-470-37603-4 Manufactured in the United States of America 10 9 8 7 6 5 4 3 2 1 Library of Congress Cataloging-in-Publication Data is available from the publisher. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600. Requests to the Publisher for permis- sion should be addressed to the Legal Department, Wiley Publishing, Inc., 10475 Crosspoint Blvd., Indianapolis, IN 46256, (317) 572-3447, fax (317) 572-4355, or online at http://www.wiley.com/go/permissions. -
Linux Kernel and Driver Development Training Slides
Linux Kernel and Driver Development Training Linux Kernel and Driver Development Training © Copyright 2004-2021, Bootlin. Creative Commons BY-SA 3.0 license. Latest update: October 9, 2021. Document updates and sources: https://bootlin.com/doc/training/linux-kernel Corrections, suggestions, contributions and translations are welcome! embedded Linux and kernel engineering Send them to [email protected] - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 1/470 Rights to copy © Copyright 2004-2021, Bootlin License: Creative Commons Attribution - Share Alike 3.0 https://creativecommons.org/licenses/by-sa/3.0/legalcode You are free: I to copy, distribute, display, and perform the work I to make derivative works I to make commercial use of the work Under the following conditions: I Attribution. You must give the original author credit. I Share Alike. If you alter, transform, or build upon this work, you may distribute the resulting work only under a license identical to this one. I For any reuse or distribution, you must make clear to others the license terms of this work. I Any of these conditions can be waived if you get permission from the copyright holder. Your fair use and other rights are in no way affected by the above. Document sources: https://github.com/bootlin/training-materials/ - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 2/470 Hyperlinks in the document There are many hyperlinks in the document I Regular hyperlinks: https://kernel.org/ I Kernel documentation links: dev-tools/kasan I Links to kernel source files and directories: drivers/input/ include/linux/fb.h I Links to the declarations, definitions and instances of kernel symbols (functions, types, data, structures): platform_get_irq() GFP_KERNEL struct file_operations - Kernel, drivers and embedded Linux - Development, consulting, training and support - https://bootlin.com 3/470 Company at a glance I Engineering company created in 2004, named ”Free Electrons” until Feb. -
Of Mobile Devices: a Survey on Network Traffic Analysis
1 The Dark Side(-Channel) of Mobile Devices: A Survey on Network Traffic Analysis Mauro Conti, Senior Member, IEEE, QianQian Li, Alberto Maragno, and Riccardo Spolaor*, Member, IEEE. Abstract—In recent years, mobile devices (e.g., smartphones elements enable both smartphones and tablets to have the and tablets) have met an increasing commercial success and same functionalities typically offered by laptops and desktop have become a fundamental element of the everyday life for computers. billions of people all around the world. Mobile devices are used not only for traditional communication activities (e.g., voice According to the statistics reported in [1], smartphone calls and messages) but also for more advanced tasks made users were 25:3% of the global population in 2015, and this possible by an enormous amount of multi-purpose applications percentage is expected to grow till 37% in 2020. Similarly, the (e.g., finance, gaming, and shopping). As a result, those devices statistics about tablets reported in [2] indicate a global penetra- generate a significant network traffic (a consistent part of the overall Internet traffic). For this reason, the research community tion of 13:8% in 2015, expected to reach 19:2% in 2020. The has been investigating security and privacy issues that are related driving forces of this tremendous success are the ubiquitous to the network traffic generated by mobile devices, which could Internet connectivity, thanks to the worldwide deployment of be analyzed to obtain information useful for a variety of goals cellular and Wi-Fi networks, and a large number of apps (ranging from fine-grained user profiling to device security and available in the official (and unofficial) marketplaces. -
PF: the Openbsd Packet Filter
PF: The OpenBSD Packet Filter Languages: [en] [de] [es] [fr] [id] [ja] [pl] [up to FAQ] [Next: Getting Started] PF: The OpenBSD Packet Filter Table of Contents ● Basic Configuration ❍ Getting Started ❍ Lists and Macros ❍ Tables ❍ Packet Filtering ❍ Network Address Translation ❍ Traffic Redirection (Port Forwarding) ❍ Shortcuts For Creating Rulesets ● Advanced Configuration ❍ Runtime Options ❍ Scrub (Packet Normalization) ❍ Anchors and Named (Sub) Rulesets ❍ Packet Queueing and Prioritization ❍ Address Pools and Load Balancing ❍ Packet Tagging ● Additional Topics ❍ Logging ❍ Performance ❍ Issues with FTP ❍ Authpf: User Shell for Authenticating Gateways ● Example Rulesets ❍ Example: Firewall for Home or Small Office Packet Filter (from here on referred to as PF) is OpenBSD's system for filtering TCP/IP traffic and doing Network Address Translation. PF is also capable of normalizing and conditioning TCP/IP traffic and providing bandwidth control and packet prioritization. PF has been a part of the GENERIC OpenBSD kernel since OpenBSD 3.0. Previous OpenBSD releases used a different firewall/NAT package which is no longer supported. PF was originally developed by Daniel Hartmeier and is now maintained and developed by Daniel and the rest of the OpenBSD team. This set of documents is intended as a general introduction to the PF system as run on OpenBSD. It is intended to be used as a supplement to the man pages, not as a replacement for them. This document covers all of PF's major features. For a complete and http://www.openbsd.org/faq/pf/index.html (1 of 2) [02/06/2005 14:54:58] PF: The OpenBSD Packet Filter in-depth view of what PF can do, please start by reading the pf(4) man page. -
David Gwynne <[email protected]>
firewalling with OpenBSD's pf and pfsync David Gwynne <[email protected]> Thursday, 17 January 13 introduction ‣ who am i? ‣ what is openbsd? ‣ what are pf and pfsync? ‣ how do i use them? ‣ ask questions whenever you want Thursday, 17 January 13 who am i? ‣ infrastructure architect in EAIT at UQ ‣ i do stuff, including run the firewalls ‣ a core developer in openbsd ‣ i generally play with storage ‣ but i play with the network stack sometimes Thursday, 17 January 13 what is openbsd? ‣ open source general purpose unix-like operating system ‣ descended from the original UNIX by way of berkeley and netbsd ‣ aims for “portability, standardization, correctness, proactive security and integrated cryptography.” ‣ supports various architectures/platforms Thursday, 17 January 13 what is openbsd? ‣ one source tree for everything ‣ kernel, userland, doco ‣ bsd/isc/mit style licenses on all code (with some historical exceptions) ‣ 6 month dev cycle resulting in a release ‣ 3rd party software via a ports tree ‣ emergent focus on network services Thursday, 17 January 13 what is openbsd? ‣ it is very aggressive ‣ changes up and down the stack (compiler to kernel) to make a harsher, stricter, and less predictable runtime environment ‣ minimal or no backward compatibility as things move forward ‣ whole tree is checked for new bugs ‣ randomise as much as possible all over Thursday, 17 January 13 what is openbsd? ‣ it is extremely conservative ‣ tree must compile and work at all times ‣ big changes go in at the start of the cycle ‣ we’re not afraid to back stuff out ‣ peer review is necessary ‣ we do back away from some tweaks for the sake of usability Thursday, 17 January 13 what is pf? ‣ short for packet filter ‣ the successor to IP Filter (ipf) ‣ ipf was removed due to license issues ‣ the exec summary is that it is a stateful filter for IP (v4 and v6) traffic ‣ does a little bit more than that though.. -
Tcpdump Basics
TCPdump Basics What we will cover: What is/are TCPdump/WinDump? Why use TCPdump? Installation of TCPdump on Unix/Windows It’s installed, now what? Changing the amount of data collected Reading TCPdump/WinDump Output TCP Flags in TCPdump/WinDump Absolute & Relative Sequence Numbers Dumping TCPdump/WinDump output in hexadecimal format TCPdump ManPage TCPdump is a tool we can use for packet analysis. We will not use ethereal (wireshark) because it does “too much” for us. TCPdump will keep everything “raw” and that’s the way we like it! *note: it is expected that the reader will try out all the TCPdump/WinDump commands listed in the lesson on their own computers as well as the practical exercises. You have to actually run the commands to learn how to use the tool. What is/are TCPdump/WinDump? TCPdump, and its cousin WinDump, is software that allows us to see inside the traffic activity that occurs on a network. TCPdump is a Unix tool used to gather data from the network, decipher the bits, and display the output in a human readable format (granted it does take a little bit of instruction to learn the TCPdump language). Why use TCPdump? Network traffic travels in data packets; each data packet contains the information that it needs to travel across the network. This information is contained in a TCP header. A TCP header will contain the destination and source address, state information, and protocol identifiers. The rest of the packet contains the data that is being sent. Devices that are responsible for routing read the information in these packets and send them to their correct destination.