Peer-To-Peer Communication Across Network Address Translators
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A Secure Peer-To-Peer Web Framework
A Secure Peer-to-Peer Web Framework Joakim Koskela Andrei Gurtov Helsinki Institute for Information Technology Helsinki Institute for Information Technology PO Box 19800, 00076 Aalto PO Box 19800, 00076 Aalto Email: joakim.koskela@hiit.fi Email: andrei.gurtov@hiit.fi Abstract—We present the design and evaluation of a se- application, that can be deployed without investing in dedi- cure peer-to-peer HTTP middleware framework that enables cated infrastructure while addressing issues such as middlebox a multitude of web applications without relying on service traversal, mobility, security and identity management. providers. The framework is designed to be deployed in existing network environments, allowing ordinary users to create private II. PEER-TO-PEER HTTP services without investing in network infrastructure. Compared to previous work, scalability, NAT/firewall traversal and peer From its launch in the early 1990s, the HyperText Transfer mobility is achieved without the need for maintaining dedicated Protocol (HTTP) had grown to be one of the most popular servers by utilizing new network protocols and re-using existing protocols on the Internet today. It is used daily for everything network resources. from past-time activities, such as recreational browsing, gam- I. INTRODUCTION ing and media downloads, to business- and security-critical Peer-to-peer (P2P) systems have been popular within net- applications such as payment systems and on-line banking. work research during the past years as they have the potential The success of HTTP has clearly grown beyond its original to offer more reliable, fault-tolerant and cost-efficient network- design as a simple, easy to manage protocol for exchanging ing. -
I.L. 40-614A 1 1. INTRODUCTION the Basic Interface to Remote Terminal, Or BIRT, Is an INCOM Network Master. BIRT Gives Users An
I.L. 40-614A 1. INTRODUCTION 3. DESCRIPTION The Basic Interface to Remote Terminal, or BIRT, is 3.1. Power Requirements an INCOM Network Master. BIRT gives users an economical way of getting information from their Range: 48 Vdc to 250 Vdc and 120 Vac INCOM-compatible devices since it connects directly between a user’s external MODEM or personal com- Burden: 3.5 W @ 48 Vdc puter and the INCOM network. 9 W @ 250 Vdc 5 W @ 120 Vac BIRT can directly replace Westinghouse MINTs, talk- ing to all INCOM-based communication devices. 3.2. Temperature Range BIRTs also include a special high-speed mode for communicating with SADIs – allowing users to collect For Operation: 0˚ to +55˚ C data from other manufacturer’s relays more rapidly For Storage: -20˚ to +80˚ C than ever before. 3.3. Physical Dimensions BIRTs are built to handle the abuse of substation environment; their “hardened” RS-232 serial port can The BIRT enclosure dimensions are identical to the handle surges and sustained high voltages that ERNI and SADI, as shown in figure 1. would destroy ordinary serial ports, and BIRTs can run on a wide range of voltages, from 48 to 250 Vdc Dimensions and weight of chassis or even 120 Vac, with no jumpers or adjustments needed. Height: 5.26” (133.6) mm) Width: 3.32” (84.3) mm) Depth: 5.92” (150.4) mm) 2. FEATURES Weight: 2.0 lbs (0.9 kg) BIRT is designed to be very flexible in its RS-232 External Wiring: See figures 2 and 3. -
Windows Command Prompt Cheatsheet
Windows Command Prompt Cheatsheet - Command line interface (as opposed to a GUI - graphical user interface) - Used to execute programs - Commands are small programs that do something useful - There are many commands already included with Windows, but we will use a few. - A filepath is where you are in the filesystem • C: is the C drive • C:\user\Documents is the Documents folder • C:\user\Documents\hello.c is a file in the Documents folder Command What it Does Usage dir Displays a list of a folder’s files dir (shows current folder) and subfolders dir myfolder cd Displays the name of the current cd filepath chdir directory or changes the current chdir filepath folder. cd .. (goes one directory up) md Creates a folder (directory) md folder-name mkdir mkdir folder-name rm Deletes a folder (directory) rm folder-name rmdir rmdir folder-name rm /s folder-name rmdir /s folder-name Note: if the folder isn’t empty, you must add the /s. copy Copies a file from one location to copy filepath-from filepath-to another move Moves file from one folder to move folder1\file.txt folder2\ another ren Changes the name of a file ren file1 file2 rename del Deletes one or more files del filename exit Exits batch script or current exit command control echo Used to display a message or to echo message turn off/on messages in batch scripts type Displays contents of a text file type myfile.txt fc Compares two files and displays fc file1 file2 the difference between them cls Clears the screen cls help Provides more details about help (lists all commands) DOS/Command Prompt help command commands Source: https://technet.microsoft.com/en-us/library/cc754340.aspx. -
How to Find out the IP Address of an Omron
Communications Middleware/Network Browser How to find an Omron Controller’s IP address Valin Corporation | www.valin.com Overview • Many Omron PLC’s have Ethernet ports or Ethernet port options • The IP address for a PLC is usually changed by the programmer • Most customers do not mark the controller with IP address (label etc.) • Very difficult to communicate to the PLC over Ethernet if the IP address is unknown. Valin Corporation | www.valin.com Simple Ethernet Network Basics IP address is up to 12 digits (4 octets) Ex:192.168.1.1 For MOST PLC programming applications, the first 3 octets are the network address and the last is the node address. In above example 192.168.1 is network address, 1 is node address. For devices to communicate on a simple network: • Every device IP Network address must be the same. • Every device node number must be different. Device Laptop EX: Omron PLC 192.168.1.1 192.168.1.1 Device Laptop EX: Omron PLC 127.27.250.5 192.168.1.1 Device Laptop EX: Omron PLC 192.168.1.3 192.168.1.1 Valin Corporation | www.valin.com Omron Default IP Address • Most Omron Ethernet devices use one of the following IP addresses by default. Omron PLC 192.168.250.1 OR 192.168.1.1 Valin Corporation | www.valin.com PING Command • PING is a way to check if the device is connected (both virtually and physically) to the network. • Windows Command Prompt command. • PC must use the same network number as device (See previous) • Example: “ping 172.21.90.5” will test to see if a device with that IP address is connected to the PC. -
Distributed Deep Learning in Open Collaborations
Distributed Deep Learning In Open Collaborations Michael Diskin∗y~ Alexey Bukhtiyarov∗| Max Ryabinin∗y~ Lucile Saulnierz Quentin Lhoestz Anton Sinitsiny~ Dmitry Popovy~ Dmitry Pyrkin~ Maxim Kashirin~ Alexander Borzunovy~ Albert Villanova del Moralz Denis Mazur| Ilia Kobelevy| Yacine Jernitez Thomas Wolfz Gennady Pekhimenko♦♠ y Yandex, Russia z Hugging Face, USA ~ HSE University, Russia | Moscow Institute of Physics and Technology, Russia } University of Toronto, Canada ♠ Vector Institute, Canada Abstract Modern deep learning applications require increasingly more compute to train state-of-the-art models. To address this demand, large corporations and institutions use dedicated High-Performance Computing clusters, whose construction and maintenance are both environmentally costly and well beyond the budget of most organizations. As a result, some research directions become the exclusive domain of a few large industrial and even fewer academic actors. To alleviate this disparity, smaller groups may pool their computational resources and run collaborative experiments that benefit all participants. This paradigm, known as grid- or volunteer computing, has seen successful applications in numerous scientific areas. However, using this approach for machine learning is difficult due to high latency, asymmetric bandwidth, and several challenges unique to volunteer computing. In this work, we carefully analyze these constraints and propose a novel algorithmic framework designed specifically for collaborative training. We demonstrate the effectiveness of our approach for SwAV and ALBERT pretraining in realistic conditions and achieve performance comparable to traditional setups at a fraction of the cost. arXiv:2106.10207v1 [cs.LG] 18 Jun 2021 Finally, we provide a detailed report of successful collaborative language model pretraining with 40 participants. 1 Introduction The deep learning community is becoming increasingly more reliant on transfer learning. -
AMNESIA 33: How TCP/IP Stacks Breed Critical Vulnerabilities in Iot
AMNESIA:33 | RESEARCH REPORT How TCP/IP Stacks Breed Critical Vulnerabilities in IoT, OT and IT Devices Published by Forescout Research Labs Written by Daniel dos Santos, Stanislav Dashevskyi, Jos Wetzels and Amine Amri RESEARCH REPORT | AMNESIA:33 Contents 1. Executive summary 4 2. About Project Memoria 5 3. AMNESIA:33 – a security analysis of open source TCP/IP stacks 7 3.1. Why focus on open source TCP/IP stacks? 7 3.2. Which open source stacks, exactly? 7 3.3. 33 new findings 9 4. A comparison with similar studies 14 4.1. Which components are typically flawed? 16 4.2. What are the most common vulnerability types? 17 4.3. Common anti-patterns 22 4.4. What about exploitability? 29 4.5. What is the actual danger? 32 5. Estimating the reach of AMNESIA:33 34 5.1. Where you can see AMNESIA:33 – the modern supply chain 34 5.2. The challenge – identifying and patching affected devices 36 5.3. Facing the challenge – estimating numbers 37 5.3.1. How many vendors 39 5.3.2. What device types 39 5.3.3. How many device units 40 6. An attack scenario 41 6.1. Other possible attack scenarios 44 7. Effective IoT risk mitigation 45 8. Conclusion 46 FORESCOUT RESEARCH LABS RESEARCH REPORT | AMNESIA:33 A note on vulnerability disclosure We would like to thank the CERT Coordination Center, the ICS-CERT, the German Federal Office for Information Security (BSI) and the JPCERT Coordination Center for their help in coordinating the disclosure of the AMNESIA:33 vulnerabilities. -
User Datagram Protocol - Wikipedia, the Free Encyclopedia Página 1 De 6
User Datagram Protocol - Wikipedia, the free encyclopedia Página 1 de 6 User Datagram Protocol From Wikipedia, the free encyclopedia The five-layer TCP/IP model User Datagram Protocol (UDP) is one of the core 5. Application layer protocols of the Internet protocol suite. Using UDP, programs on networked computers can send short DHCP · DNS · FTP · Gopher · HTTP · messages sometimes known as datagrams (using IMAP4 · IRC · NNTP · XMPP · POP3 · Datagram Sockets) to one another. UDP is sometimes SIP · SMTP · SNMP · SSH · TELNET · called the Universal Datagram Protocol. RPC · RTCP · RTSP · TLS · SDP · UDP does not guarantee reliability or ordering in the SOAP · GTP · STUN · NTP · (more) way that TCP does. Datagrams may arrive out of order, 4. Transport layer appear duplicated, or go missing without notice. TCP · UDP · DCCP · SCTP · RTP · Avoiding the overhead of checking whether every RSVP · IGMP · (more) packet actually arrived makes UDP faster and more 3. Network/Internet layer efficient, at least for applications that do not need IP (IPv4 · IPv6) · OSPF · IS-IS · BGP · guaranteed delivery. Time-sensitive applications often IPsec · ARP · RARP · RIP · ICMP · use UDP because dropped packets are preferable to ICMPv6 · (more) delayed packets. UDP's stateless nature is also useful 2. Data link layer for servers that answer small queries from huge 802.11 · 802.16 · Wi-Fi · WiMAX · numbers of clients. Unlike TCP, UDP supports packet ATM · DTM · Token ring · Ethernet · broadcast (sending to all on local network) and FDDI · Frame Relay · GPRS · EVDO · multicasting (send to all subscribers). HSPA · HDLC · PPP · PPTP · L2TP · ISDN · (more) Common network applications that use UDP include 1. -
Xerox® Colorqube 8580/8880 Color Printer 3 System Administrator Guide
Xerox® ColorQube® 8580 / 8880 Color Printer Imprimante couleur System Administrator Guide Guide de l’administrateur système © 2015 Xerox Corporation. All rights reserved. Unpublished rights reserved under the copyright laws of the United States. Contents of this publication may not be reproduced in any form without permission of Xerox Corporation. Copyright protection claimed includes all forms of matters of copyrightable materials and information now allowed by statutory or judicial law or hereinafter granted, including without limitation, material generated from the software programs which are displayed on the screen such as styles, templates, icons, screen displays, looks, and so on. Xerox® and Xerox and Design®, Phaser®, PhaserSMART®, PhaserMatch®, PhaserCal®, PhaserMeter™, CentreWare®, PagePack®, eClick®, PrintingScout®, Walk-Up®, WorkCentre®, FreeFlow®, SMARTsend®, Scan to PC Desktop®, MeterAssistant®, SuppliesAssistant®, Xerox Secure Access Unified ID System®, Xerox Extensible Interface Platform®, ColorQube®, Global Print Driver®, and Mobile Express Driver® are trademarks of Xerox Corporation in the United States and/or other countries. Adobe® Reader®, Adobe® Type Manager®, ATM™, Flash®, Macromedia®, Photoshop®, and PostScript® are trademarks of Adobe Systems Incorporated in the United States and/or other countries. Apple, Bonjour, EtherTalk, TrueType, iPad, iPhone, iPod, iPod touch, Mac and Mac OS are trademarks of Apple Inc., registered in the U.S. and other countries. AirPrint and the AirPrint logo are trademarks of Apple Inc. HP-GL®, HP-UX®, and PCL® are trademarks of Hewlett-Packard Corporation in the United States and/or other countries. IBM® and AIX® are trademarks of International Business Machines Corporation in the United States and/or other countries. Microsoft®, Windows Vista®, Windows®, and Windows Server® are trademarks of Microsoft Corporation in the United States and other countries. -
Introduction to Peer-To-Peer Networks
Introduction to Peer-to-Peer Networks The Story of Peer-to-Peer The Nature of Peer-to-Peer: Generals & Paradigms Unstructured Peer-to-Peer Systems Sample Applications 1 Prof. Dr. Thomas Schmidt http:/www.informatik.haw-hamburg.de/~schmidt A Peer-to-Peer system is a self-organizing system of equal, autonomous entities (peers) which aims for the shared usage of distributed resources in a networked environment avoiding central services. Andy Oram 2 Prof. Dr. Thomas Schmidt http:/www.informatik.haw-hamburg.de/~schmidt The Old Days NetNews (nntp) Usenet since 1979, initially based on UUCP Exchange (replication) of news articles by subscription Group creation/deletion decentralised DNS Distributed delegation of name authorities: file sharing of host tables Name “Servers” act as peers Hierarchical information space permits exponential growth Systems are manually configured distributed peers 3 Prof. Dr. Thomas Schmidt http:/www.informatik.haw-hamburg.de/~schmidt SETI@home: Distributed Computing Search for Extraterrestrial Intelligence (SETI) Analyse radio sig- nals from space Globally shared computing res. Idea 1995 First version 1998 2002 ≈ 4 Mio clnt E.g. Screensaver From Anderson et. al.: SETI@home, Comm. ACM, 45 (11), Nov. 2002 http://setiathome.berkeley.edu/ - ongoing 4 Prof. Dr. Thomas Schmidt http:/www.informatik.haw-hamburg.de/~schmidt SETI@home (2) http-based client-server model No client-client communication Data chunks: load & return N-redundancy for fault detection Attacks: bogus code From Anderson -
Peer-To-Peer Networks
Peer-to-Peer Networks 14-740: Fundamentals of Computer Networks Credit to Bill Nace, 14-740, Fall 2017 Material from Computer Networking: A Top Down Approach, 6th edition. J.F. Kurose and K.W. Ross traceroute • P2P Overview • Architecture components • Napster (Centralized) • Gnutella (Distributed) • Skype and KaZaA (Hybrid, Hierarchical) • KaZaA Reverse Engineering Study 14-740: Spring 2018 2 What is P2P? • Client / Server interaction • Client: any end-host • Server: specific end-host • P2P: Peer-to-peer • Any end-host • Aim to leverage resources available on “clients” (peers) • Hard drive space • Bandwidth (especially upload) • Computational power • Anonymity (i.e. Zombie botnets) • “Edge-ness” (i.e. being distributed at network edges) • Clients are particularly fickle • Users have not agreed to provide any particular level of service • Users are not altruistic -- algorithm must force participation without allowing cheating • Clients are not trusted • Client code may be modified • And yet, availability of resources must be assured P2P History • Proto-P2P systems exist • DNS, Netnews/Usenet • Xerox Grapevine (~1982): name, mail delivery service • Kicked into high gear in 1999 • Many users had “always-on” broadband net connections • 1st Generation: Napster (music exchange) • 2nd Generation: Freenet, Gnutella, Kazaa, BitTorrent • More scalable, designed for anonymity, fault-tolerant • 3rd Generation: Middleware -- Pastry, Chord • Provide for overlay routing to place/find resources 14-740: Spring 2018 6 P2P Architecture • Content Directory -
Cs-204: Computer Networks
CS-204: COMPUTER NETWORKS Lecture 5 Chapter 19- Network Layer: Logical Addressing Instructor: Dr. Vandana Kushwaha 1. INTRODUCTION Communication at the network layer is host-to-host (computer-to-computer); a computer somewhere in the world needs to communicate with another computer somewhere else in the world. Usually, computers communicate through the Internet. The packet transmitted by the sending computer may pass through several LANs or WANs before reaching the destination computer. For this level of communication, we need a global addressing scheme; we called this logical addressing or IP address. 2. IPv4 ADDRESSES An IPv4 address is a 32-bit address that uniquely and universally defines the connection of a device (for example, a computer or a router) to the Internet. IPv4 addresses are unique. They are unique in the sense that each address defines one, and only one, connection to the Internet. Two devices on the Internet can never have the same address at the same time. But by using some strategies, an address may be assigned to a device for a time period and then taken away and assigned to another device. On the other hand, if a device operating at the network layer has m connections to the Internet, it needs to have m addresses. A router is such a device which needs as many IP addresses as the number of ports are there in it. 2.1. Address Space A protocol such as IPv4 that defines addresses has an address space. An address space is the total number of addresses used by the protocol. If a protocol uses N bits to define an address, the address space is 2N because each bit can have two different values (0 or 1) and N bits can have 2N values. -
Routing Loop Attacks Using Ipv6 Tunnels
Routing Loop Attacks using IPv6 Tunnels Gabi Nakibly Michael Arov National EW Research & Simulation Center Rafael – Advanced Defense Systems Haifa, Israel {gabin,marov}@rafael.co.il Abstract—IPv6 is the future network layer protocol for A tunnel in which the end points’ routing tables need the Internet. Since it is not compatible with its prede- to be explicitly configured is called a configured tunnel. cessor, some interoperability mechanisms were designed. Tunnels of this type do not scale well, since every end An important category of these mechanisms is automatic tunnels, which enable IPv6 communication over an IPv4 point must be reconfigured as peers join or leave the tun- network without prior configuration. This category includes nel. To alleviate this scalability problem, another type of ISATAP, 6to4 and Teredo. We present a novel class of tunnels was introduced – automatic tunnels. In automatic attacks that exploit vulnerabilities in these tunnels. These tunnels the egress entity’s IPv4 address is computationally attacks take advantage of inconsistencies between a tunnel’s derived from the destination IPv6 address. This feature overlay IPv6 routing state and the native IPv6 routing state. The attacks form routing loops which can be abused as a eliminates the need to keep an explicit routing table at vehicle for traffic amplification to facilitate DoS attacks. the tunnel’s end points. In particular, the end points do We exhibit five attacks of this class. One of the presented not have to be updated as peers join and leave the tunnel. attacks can DoS a Teredo server using a single packet. The In fact, the end points of an automatic tunnel do not exploited vulnerabilities are embedded in the design of the know which other end points are currently part of the tunnels; hence any implementation of these tunnels may be vulnerable.