Route Selection Feature Overview and Configuration Guide
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
RED HAT ENTERPRISE LINUX 5, 6, and 7 Common Administrative
RED HAT ENTERPRISE LINUX 5, 6, AND 7 SOFTWARE MANAGEMENT NETWORKING Common administrative commands TASK RHEL TASK RHEL yum install iptables and ip6tables 5 6 5 yum groupinstall /etc/sysconfig/ip*tables Install software iptables and ip6tables 1 Be aware of potential issues when using subscription-manager yum install 7 Configure firewall /etc/sysconfig/ip*tables 6 SYSTEM BASICS on Red Hat Enterprise Linux 5: https://access.redhat.com/ yum group install system-config-firewall solutions/129003. TASK RHEL yum info firewall-cmd 2 Subscription-manager is used for Satellite 6, Satellite 5.6 with 5 6 7 SAM and newer, and Red Hat’s CDN. yum groupinfo firewall-config /etc/sysconfig/rhn/systemid 5 3 RHN tools are deprecated on Red Hat Enterprise Linux 7. View software info /etc/hosts yum info 5 6 rhn_register should be used for Satellite server 5.6 and newer 7 /etc/resolv.conf /etc/sysconfig/rhn/systemid yum group info View subscription information 6 only. For details, see: Satellite 5.6 unable to register RHEL 7 Configure name subscription-manager identity client system due to rhn-setup package not included in Minimal resolution /etc/hosts installation (https://access.redhat.com/solutions/737373) Update software yum update 5 6 7 /etc/resolv.conf 7 subscription-manager identity 7 nmcli con mod rhn_register 5 Upgrade software yum upgrade 5 6 7 /etc/sysconfig/network 5 6 subscription-manager 1 Configure hostname hostnamectl rhn_register Configure software subscription-manager repos 5 6 7 /etc/hostname 7 rhnreg_ks 6 /etc/yum.repos.d/*.repo Configure -
Configuring Static Routing
Configuring Static Routing This chapter contains the following sections: • Finding Feature Information, on page 1 • Information About Static Routing, on page 1 • Licensing Requirements for Static Routing, on page 4 • Prerequisites for Static Routing, on page 4 • Guidelines and Limitations for Static Routing, on page 4 • Default Settings for Static Routing Parameters, on page 4 • Configuring Static Routing, on page 4 • Verifying the Static Routing Configuration, on page 10 • Related Documents for Static Routing, on page 10 • Feature History for Static Routing, on page 10 Finding Feature Information Your software release might not support all the features documented in this module. For the latest caveats and feature information, see the Bug Search Tool at https://tools.cisco.com/bugsearch/ and the release notes for your software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "New and Changed Information"chapter or the Feature History table in this chapter. Information About Static Routing Routers forward packets using either route information from route table entries that you manually configure or the route information that is calculated using dynamic routing algorithms. Static routes, which define explicit paths between two routers, cannot be automatically updated; you must manually reconfigure static routes when network changes occur. Static routes use less bandwidth than dynamic routes. No CPU cycles are used to calculate and analyze routing updates. You can supplement dynamic routes with static routes where appropriate. You can redistribute static routes into dynamic routing algorithms but you cannot redistribute routing information calculated by dynamic routing algorithms into the static routing table. -
What Is Routing?
What is routing? • forwarding – moving packets between ports - Look up destination address in forwarding table - Find out-port or hout-port, MAC addri pair • Routing is process of populat- ing forwarding table - Routers exchange messages about nets they can reach - Goal: Find optimal route for ev- ery destination - . or maybe good route, or just any route (depending on scale) Routing algorithm properties • Static vs. dynamic - Static: routes change slowly over time - Dynamic: automatically adjust to quickly changing network conditions • Global vs. decentralized - Global: All routers have complete topology - Decentralized: Only know neighbors & what they tell you • Intra-domain vs. Inter-domain routing - Intra-: All routers under same administrative control - Intra-: Scale to ∼100 networks (e.g., campus like Stanford) - Inter-: Decentralized, scale to Internet Optimality A 6 1 3 2 F 1 E B 4 1 9 C D • View network as a graph • Assign cost to each edge - Can be based on latency, b/w, utilization, queue length, . • Problem: Find lowest cost path between two nodes - Must be computed in distributed way Distance Vector • Local routing algorithm • Each node maintains a set of triples - (Destination, Cost, NextHop) • Exchange updates w. directly connected neighbors - periodically (on the order of several seconds to minutes) - whenever table changes (called triggered update) • Each update is a list of pairs: - (Destination, Cost) • Update local table if receive a “better” route - smaller cost - from newly connected/available neighbor • Refresh existing -
Don't Trust Traceroute (Completely)
Don’t Trust Traceroute (Completely) Pietro Marchetta, Valerio Persico, Ethan Katz-Bassett Antonio Pescapé University of Southern California, CA, USA University of Napoli Federico II, Italy [email protected] {pietro.marchetta,valerio.persico,pescape}@unina.it ABSTRACT In this work, we propose a methodology based on the alias resolu- tion process to demonstrate that the IP level view of the route pro- vided by traceroute may be a poor representation of the real router- level route followed by the traffic. More precisely, we show how the traceroute output can lead one to (i) inaccurately reconstruct the route by overestimating the load balancers along the paths toward the destination and (ii) erroneously infer routing changes. Categories and Subject Descriptors C.2.1 [Computer-communication networks]: Network Architec- ture and Design—Network topology (a) Traceroute reports two addresses at the 8-th hop. The common interpretation is that the 7-th hop is splitting the traffic along two Keywords different forwarding paths (case 1); another explanation is that the 8- th hop is an RFC compliant router using multiple interfaces to reply Internet topology; Traceroute; IP alias resolution; IP to Router to the source (case 2). mapping 1 1. INTRODUCTION 0.8 Operators and researchers rely on traceroute to measure routes and they assume that, if traceroute returns different IPs at a given 0.6 hop, it indicates different paths. However, this is not always the case. Although state-of-the-art implementations of traceroute al- 0.4 low to trace all the paths -
Dynamic Routing: Routing Information Protocol
CS 356: Computer Network Architectures Lecture 12: Dynamic Routing: Routing Information Protocol Chap. 3.3.1, 3.3.2 Xiaowei Yang [email protected] Today • ICMP applications • Dynamic Routing – Routing Information Protocol ICMP applications • Ping – ping www.duke.edu • Traceroute – traceroute nytimes.com • MTU discovery Ping: Echo Request and Reply ICMP ECHO REQUEST Host Host or or Router router ICMP ECHO REPLY Type Code Checksum (= 8 or 0) (=0) identifier sequence number 32-bit sender timestamp Optional data • Pings are handled directly by the kernel • Each Ping is translated into an ICMP Echo Request • The Pinged host responds with an ICMP Echo Reply 4 Traceroute • xwy@linux20$ traceroute -n 18.26.0.1 – traceroute to 18.26.0.1 (18.26.0.1), 30 hops max, 60 byte packets – 1 152.3.141.250 4.968 ms 4.990 ms 5.058 ms – 2 152.3.234.195 1.479 ms 1.549 ms 1.615 ms – 3 152.3.234.196 1.157 ms 1.171 ms 1.238 ms – 4 128.109.70.13 1.905 ms 1.885 ms 1.943 ms – 5 128.109.70.138 4.011 ms 3.993 ms 4.045 ms – 6 128.109.70.102 10.551 ms 10.118 ms 10.079 ms – 7 18.3.3.1 28.715 ms 28.691 ms 28.619 ms – 8 18.168.0.23 27.945 ms 28.028 ms 28.080 ms – 9 18.4.7.65 28.037 ms 27.969 ms 27.966 ms – 10 128.30.0.246 27.941 ms * * Traceroute algorithm • Sends out three UDP packets with TTL=1,2,…,n, destined to a high port • Routers on the path send ICMP Time exceeded message with their IP addresses until n reaches the destination distance • Destination replies with port unreachable ICMP messages Path MTU discovery algorithm • Send packets with DF bit set • If receive an ICMP error message, reduce the packet size Today • ICMP applications • Dynamic Routing – Routing Information Protocol Dynamic Routing • There are two parts related to IP packet handling: 1. -
The Routing Table V1.12 – Aaron Balchunas 1
The Routing Table v1.12 – Aaron Balchunas 1 - The Routing Table - Routing Table Basics Routing is the process of sending a packet of information from one network to another network. Thus, routes are usually based on the destination network, and not the destination host (host routes can exist, but are used only in rare circumstances). To route, routers build Routing Tables that contain the following: • The destination network and subnet mask • The “next hop” router to get to the destination network • Routing metrics and Administrative Distance The routing table is concerned with two types of protocols: • A routed protocol is a layer 3 protocol that applies logical addresses to devices and routes data between networks. Examples would be IP and IPX. • A routing protocol dynamically builds the network, topology, and next hop information in routing tables. Examples would be RIP, IGRP, OSPF, etc. To determine the best route to a destination, a router considers three elements (in this order): • Prefix-Length • Metric (within a routing protocol) • Administrative Distance (between separate routing protocols) Prefix-length is the number of bits used to identify the network, and is used to determine the most specific route. A longer prefix-length indicates a more specific route. For example, assume we are trying to reach a host address of 10.1.5.2/24. If we had routes to the following networks in the routing table: 10.1.5.0/24 10.0.0.0/8 The router will do a bit-by-bit comparison to find the most specific route (i.e., longest matching prefix). -
Oracle® Solaris 11.4 Network Administration Cheatsheet
Oracle Solaris 11.4 Network Administration Cheatsheet This cheatsheet includes examples of commonly used network administration commands. See the dladm(8), ipadm(8), and route(8) man pages for further details. For more information about configuring the network in Oracle Solaris 11.4, see Configuring and Managing Network Components in Oracle Solaris 11.4. Commonly Used Network Administration Commands Note - Some of following commands include parameters and values that are provided as examples only. Action Command Administering Datalinks Display all of the datalinks (physical and virtual) on a system. # dladm show-link Display all of the physical datalinks on a system. # dladm show-phys Display all of the properties for all of the datalinks on a system. # dladm show-linkprop Display all of the properties for a specific datalink on a system. # dladm show-linkprop net0 Display a specific property for a specific datalink on a system. # dladm show-linkprop -p mtu net0 Administering IP Interfaces and Addresses Display general information about a system's IP interfaces. # ipadm Display a system's IP interfaces and addresses. # ipadm show-addr Create an IP interface and then configure a static IPv4 address for that interface. # ipadm create-ip net0 # ipadm create-addr -a 203.0.113.0/24 net0/addr Obtain an IP address from a DHCP server. # ipadm create-ip net0 # ipadm create-addr -T dhcp net0/addr Create an auto-generated IPv6 address. # ipadm create-ip net0 # ipadm create-addr -T addrconf net0/addr Change the netmask property for an IP address object name (net3/v4) to 8. # ipadm set-addrprop -p prefixlen=8 net3/v4 Configure a persistent default route on a system. -
Blue Coat SGOS Command Line Interface Reference, Version 4.2.3
Blue Coat® Systems ProxySG™ Command Line Interface Reference Version SGOS 4.2.3 Blue Coat ProxySG Command Line Interface Reference Contact Information Blue Coat Systems Inc. 420 North Mary Ave Sunnyvale, CA 94085-4121 http://www.bluecoat.com/support/contact.html [email protected] http://www.bluecoat.com For concerns or feedback about the documentation: [email protected] Copyright© 1999-2006 Blue Coat Systems, Inc. All rights reserved worldwide. No part of this document may be reproduced by any means nor modified, decompiled, disassembled, published or distributed, in whole or in part, or translated to any electronic medium or other means without the written consent of Blue Coat Systems, Inc. All right, title and interest in and to the Software and documentation are and shall remain the exclusive property of Blue Coat Systems, Inc. and its licensors. ProxySG™, ProxyAV™, CacheOS™, SGOS™, Spyware Interceptor™, Scope™, RA Connector™, RA Manager™, Remote Access™ are trademarks of Blue Coat Systems, Inc. and CacheFlow®, Blue Coat®, Accelerating The Internet®, WinProxy®, AccessNow®, Ositis®, Powering Internet Management®, The Ultimate Internet Sharing Solution®, Permeo®, Permeo Technologies, Inc.®, and the Permeo logo are registered trademarks of Blue Coat Systems, Inc. All other trademarks contained in this document and in the Software are the property of their respective owners. BLUE COAT SYSTEMS, INC. DISCLAIMS ALL WARRANTIES, CONDITIONS OR OTHER TERMS, EXPRESS OR IMPLIED, STATUTORY OR OTHERWISE, ON SOFTWARE AND DOCUMENTATION FURNISHED HEREUNDER INCLUDING WITHOUT LIMITATION THE WARRANTIES OF DESIGN, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL BLUE COAT SYSTEMS, INC., ITS SUPPLIERS OR ITS LICENSORS BE LIABLE FOR ANY DAMAGES, WHETHER ARISING IN TORT, CONTRACT OR ANY OTHER LEGAL THEORY EVEN IF BLUE COAT SYSTEMS, INC. -
P2P Resource Sharing in Wired/Wireless Mixed Networks 1
INT J COMPUT COMMUN, ISSN 1841-9836 Vol.7 (2012), No. 4 (November), pp. 696-708 P2P Resource Sharing in Wired/Wireless Mixed Networks J. Liao Jianwei Liao College of Computer and Information Science Southwest University of China 400715, Beibei, Chongqing, China E-mail: [email protected] Abstract: This paper presents a new routing protocol called Manager-based Routing Protocol (MBRP) for sharing resources in wired/wireless mixed networks. MBRP specifies a manager node for a designated sub-network (called as a group), in which all nodes have the similar connection properties; then all manager nodes are employed to construct the backbone overlay network with ring topology. The manager nodes act as the proxies between the internal nodes in the group and the external world, that is not only for centralized management of all nodes to a certain extent, but also for avoiding the messages flooding in the whole network. The experimental results show that compared with Gnutella2, which uses super-peers to perform similar management work, the proposed MBRP has less lookup overhead including lookup latency and lookup hop count in the most of cases. Besides, the experiments also indicate that MBRP has well configurability and good scaling properties. In a word, MBRP has less transmission cost of the shared file data, and the latency for locating the sharing resources can be reduced to a great extent in the wired/wireless mixed networks. Keywords: wired/wireless mixed network, resource sharing, manager-based routing protocol, backbone overlay network, peer-to-peer. 1 Introduction Peer-to-Peer technology (P2P) is a widely used network technology, the typical P2P network relies on the computing power and bandwidth of all participant nodes, rather than a few gathered and dedicated servers for central coordination [1, 2]. -
Command-Line IP Utilities This Document Lists Windows Command-Line Utilities That You Can Use to Obtain TCP/IP Configuration Information and Test IP Connectivity
Guide to TCP/IP: IPv6 and IPv4, 5th Edition, ISBN 978-13059-4695-8 Command-Line IP Utilities This document lists Windows command-line utilities that you can use to obtain TCP/IP configuration information and test IP connectivity. Command parameters and uses are listed for the following utilities in Tables 1 through 9: ■ Arp ■ Ipconfig ■ Netsh ■ Netstat ■ Pathping ■ Ping ■ Route ■ Tracert ARP The Arp utility reads and manipulates local ARP tables (data link address-to-IP address tables). Syntax arp -s inet_addr eth_addr [if_addr] arp -d inet_addr [if_addr] arp -a [inet_address] [-N if_addr] [-v] Table 1 ARP command parameters and uses Parameter Description -a or -g Displays current entries in the ARP cache. If inet_addr is specified, the IP and data link address of the specified computer appear. If more than one network interface uses ARP, entries for each ARP table appear. inet_addr Specifies an Internet address. -N if_addr Displays the ARP entries for the network interface specified by if_addr. -v Displays the ARP entries in verbose mode. -d Deletes the host specified by inet_addr. -s Adds the host and associates the Internet address inet_addr with the data link address eth_addr. The physical address is given as six hexadecimal bytes separated by hyphens. The entry is permanent. eth_addr Specifies physical address. if_addr If present, this specifies the Internet address of the interface whose address translation table should be modified. If not present, the first applicable interface will be used. Pyles, Carrell, and Tittel 1 Guide to TCP/IP: IPv6 and IPv4, 5th Edition, ISBN 978-13059-4695-8 IPCONFIG The Ipconfig utility displays and modifies IP address configuration information. -
Lab 5.5.2: Examining a Route
Lab 5.5.2: Examining a Route Topology Diagram Addressing Table Device Interface IP Address Subnet Mask Default Gateway S0/0/0 10.10.10.6 255.255.255.252 N/A R1-ISP Fa0/0 192.168.254.253 255.255.255.0 N/A S0/0/0 10.10.10.5 255.255.255.252 10.10.10.6 R2-Central Fa0/0 172.16.255.254 255.255.0.0 N/A N/A 192.168.254.254 255.255.255.0 192.168.254.253 Eagle Server N/A 172.31.24.254 255.255.255.0 N/A host Pod# A N/A 172.16. Pod#.1 255.255.0.0 172.16.255.254 host Pod# B N/A 172.16. Pod#. 2 255.255.0.0 172.16.255.254 S1-Central N/A 172.16.254.1 255.255.0.0 172.16.255.254 All contents are Copyright © 1992–2007 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information. Page 1 of 7 CCNA Exploration Network Fundamentals: OSI Network Layer Lab 5.5.1: Examining a Route Learning Objectives Upon completion of this lab, you will be able to: • Use the route command to modify a Windows computer routing table. • Use a Windows Telnet client command telnet to connect to a Cisco router. • Examine router routes using basic Cisco IOS commands. Background For packets to travel across a network, a device must know the route to the destination network. This lab will compare how routes are used in Windows computers and the Cisco router. -
Routing Tables
Routing Tables A routing table is a grouping of information stored on a networked computer or network router that includes a list of routes to various network destinations. The data is normally stored in a database table and in more advanced configurations includes performance metrics associated with the routes stored in the table. Additional information stored in the table will include the network topology closest to the router. Although a routing table is routinely updated by network routing protocols, static entries can be made through manual action on the part of a network administrator. How Does a Routing Table Work? Routing tables work similar to how the post office delivers mail. When a network node on the Internet or a local network needs to send information to another node, it first requires a general idea of where to send the information. If the destination node or address is not connected directly to the network node, then the information has to be sent via other network nodes. In order to save resources, most local area network nodes will not maintain a complex routing table. Instead, they will send IP packets of information to a local network gateway. The gateway maintains the primary routing table for the network and will send the data packet to the desired location. In order to maintain a record of how to route information, the gateway will use a routing table that keeps track of the appropriate destination for outgoing data packets. All routing tables maintain routing table lists for the reachable destinations from the router’s location.