||Home||Switchboard||Unix Administration||Red Hat||TCP/IP Networks||Neoliberalism||Toxic Managers|
|(slightly skeptical) Educational society promoting "Back to basics" movement against IT overcomplexity and bastardization of classic Unix|
|News||Solaris books||Recommended Links||DHCP Server||Selected Solaris man pages||Reference|
The Solaris DHCP client is a daemon (dhcpagent ). DHCP clients from other vendors can also use the services of the Solaris DHCP server.
The DHCP clientís process ( dhcpagent ):
The Solaris DHCP client is installed and enabled on a system during installation of the Solaris when you specify that you want to use DHCP to configure network interfaces.
The dhcpagent daemon obtains configuration information that is needed by other processes involved in booting the system. For this reason, dhcpagent is started early in the boot process by the system startup scripts; booting is suspended until the network configuration information is obtained or timeout occurs.
The presence of the file /etc/dhcp.interface (for example, /etc/dhcp.hme0) indicates to the startup scripts that DHCP is to be used on the specified interface. Upon finding a dhcp.interface file, the startup scripts start the dhcpagent .
After starting up, dhcpagent waits until it receives instructions to configure a network interface.
The startup scripts issue the ifconfig interface dhcp start command, which instructs dhcpagent to start DHCP. If commands are contained within the dhcp.interface file, they are appended to the dhcp start option of ifconfig . See the ifconfig man page for more information about options used with dhcp .
After the information packet is obtained from a DHCP server, dhcpagent configures the network interface and brings it up, controlling the interface for the duration of the lease time for the IP address. dhcpagent maintains the configuration data in an internal table held in memory.
The system startup scripts use the dhcpinfo command to extract configuration option values from the dhcpagent ís table.
The values are used in configuring the system and becoming part of the network.
The agent waits passively until a set period elapses (usually half the lease time) and then requests an extension of the lease from a DHCP server.
If dhcpagent finds that the interface is down or the IP address has changed, it does not control the interface until it is instructed by ifconfig to do so.
If dhcpagent finds that the interface is up and the IP address hasnít changed, it sends a request to the server for a lease renewal. If the lease cannot be renewed, dhcpagent takes the interface down at the end of the lease time.
The Solaris DHCP client does not need to be managed under normal system operation. It automatically starts when the system boots, renegotiates leases, and stops when the system shuts down. You cannot manually start and stop the dhcpagent daemon.
However, you can use the ifconfig command as superuser on the client machine to affect the clientís management of the network interface if necessary.
The ifconfig command lets you:
This might be useful when you change options on the server, such as adding
IP addresses or changing the subnet mask, that you want clients to use immediately.
This is useful for situations where the network interface has a valid IP
address, but the client system needs updated network options. For example, this
might be useful if you do not use DHCP to manage IP addresses, but do use it
for configuring hosts on the network.
This happens automatically, but you might want to use this if you change
the lease time and want clients to use the new lease time immediately rather
than waiting for the next attempt at lease renewal.
This happens automatically when the lease expires. You might want to issue
this command if the lease time is long and you need to take down the network
interface for an extended period of time or you are removing the system from
This enables the client to use the same IP address when it reboots.
The display includes information about whether an IP address has been bound to the client; the number of requests sent, received, and declined; flags indicating whether this is the primary interface; and times indicating when the lease was obtained, expires, and when attempts to renew it will/did start. For example:
# ifconfig hme0 dhcp status Interface State Sent Recv Declined Flags hme0 BOUND 1 1 0 [PRIMARY] (Began, Expires, Renew) = (07/15/1999 15:27, 07/17/1999 13:31, 07/16/ 1999 15:24)
The file /etc/default/dhcpagent on the client system contains tunable parameters for dhcpagent . You can use a text editor to change several parameters that affect client operation.
The file is well-documented so please refer to the file for more information about the parameters.
The lease is dropped rather than released, so the DHCP server does not know that the IP address is not in active use. If the lease is still valid when the system is rebooted, the DHCP client sends an abbreviated request to use the same IP address and network configuration information it had used before the system was rebooted. If the DHCP server permits this, the client can use the information that it wrote to disk when the system shut down. If the server does not permit using the information, the client initiates the DHCP protocol sequence described previously and obtains new network configuration information.
The DHCP client daemon can manage several different interfaces on one system simultaneously, each with its own IP address and lease time. If more than one network interface is configured for DHCP, the client issues separate requests to configure them and maintains a separate set of network configuration options for each interface.
However, although the parameters are stored separately, some of the parameters are global in nature, applying to the system as a whole, rather than to a particular network interface. Options such as hostname, NIS domain name, and timezone are global parameters and should have the same values for each interface, but it might not be the case due to errors in the information entered by the DHCP administrator. To ensure that there is only one answer to a query for a global parameter, only the parameters for the primary network interface are requested. You can insert the word primary in the /etc/dhcp. interface file for the interface you want to be treated as the primary interface.
You can use DHCP services in a network you are creating, or in an existing network.
If you are setting up a network, see Chapter 5 before attempting to set up DHCP services. If you have an existing network, continue in this chapter.
This chapter describes what you need to do before setting up DHCP service on your network.
The planning information is targeted for use with DHCP Manager, although you can also use the command-line utility dhcpconfig to set up DHCP service.
Groupthink : Two Party System as Polyarchy : Corruption of Regulators : Bureaucracies : Understanding Micromanagers and Control Freaks : Toxic Managers : Harvard Mafia : Diplomatic Communication : Surviving a Bad Performance Review : Insufficient Retirement Funds as Immanent Problem of Neoliberal Regime : PseudoScience : Who Rules America : Neoliberalism : The Iron Law of Oligarchy : Libertarian Philosophy
War and Peace : Skeptical Finance : John Kenneth Galbraith :Talleyrand : Oscar Wilde : Otto Von Bismarck : Keynes : George Carlin : Skeptics : Propaganda : SE quotes : Language Design and Programming Quotes : Random IT-related quotes : Somerset Maugham : Marcus Aurelius : Kurt Vonnegut : Eric Hoffer : Winston Churchill : Napoleon Bonaparte : Ambrose Bierce : Bernard Shaw : Mark Twain Quotes
Vol 25, No.12 (December, 2013) Rational Fools vs. Efficient Crooks The efficient markets hypothesis : Political Skeptic Bulletin, 2013 : Unemployment Bulletin, 2010 : Vol 23, No.10 (October, 2011) An observation about corporate security departments : Slightly Skeptical Euromaydan Chronicles, June 2014 : Greenspan legacy bulletin, 2008 : Vol 25, No.10 (October, 2013) Cryptolocker Trojan (Win32/Crilock.A) : Vol 25, No.08 (August, 2013) Cloud providers as intelligence collection hubs : Financial Humor Bulletin, 2010 : Inequality Bulletin, 2009 : Financial Humor Bulletin, 2008 : Copyleft Problems Bulletin, 2004 : Financial Humor Bulletin, 2011 : Energy Bulletin, 2010 : Malware Protection Bulletin, 2010 : Vol 26, No.1 (January, 2013) Object-Oriented Cult : Political Skeptic Bulletin, 2011 : Vol 23, No.11 (November, 2011) Softpanorama classification of sysadmin horror stories : Vol 25, No.05 (May, 2013) Corporate bullshit as a communication method : Vol 25, No.06 (June, 2013) A Note on the Relationship of Brooks Law and Conway Law
Fifty glorious years (1950-2000): the triumph of the US computer engineering : Donald Knuth : TAoCP and its Influence of Computer Science : Richard Stallman : Linus Torvalds : Larry Wall : John K. Ousterhout : CTSS : Multix OS Unix History : Unix shell history : VI editor : History of pipes concept : Solaris : MS DOS : Programming Languages History : PL/1 : Simula 67 : C : History of GCC development : Scripting Languages : Perl history : OS History : Mail : DNS : SSH : CPU Instruction Sets : SPARC systems 1987-2006 : Norton Commander : Norton Utilities : Norton Ghost : Frontpage history : Malware Defense History : GNU Screen : OSS early history
The Peter Principle : Parkinson Law : 1984 : The Mythical Man-Month : How to Solve It by George Polya : The Art of Computer Programming : The Elements of Programming Style : The Unix Haterís Handbook : The Jargon file : The True Believer : Programming Pearls : The Good Soldier Svejk : The Power Elite
Most popular humor pages:
Manifest of the Softpanorama IT Slacker Society : Ten Commandments of the IT Slackers Society : Computer Humor Collection : BSD Logo Story : The Cuckoo's Egg : IT Slang : C++ Humor : ARE YOU A BBS ADDICT? : The Perl Purity Test : Object oriented programmers of all nations : Financial Humor : Financial Humor Bulletin, 2008 : Financial Humor Bulletin, 2010 : The Most Comprehensive Collection of Editor-related Humor : Programming Language Humor : Goldman Sachs related humor : Greenspan humor : C Humor : Scripting Humor : Real Programmers Humor : Web Humor : GPL-related Humor : OFM Humor : Politically Incorrect Humor : IDS Humor : "Linux Sucks" Humor : Russian Musical Humor : Best Russian Programmer Humor : Microsoft plans to buy Catholic Church : Richard Stallman Related Humor : Admin Humor : Perl-related Humor : Linus Torvalds Related humor : PseudoScience Related Humor : Networking Humor : Shell Humor : Financial Humor Bulletin, 2011 : Financial Humor Bulletin, 2012 : Financial Humor Bulletin, 2013 : Java Humor : Software Engineering Humor : Sun Solaris Related Humor : Education Humor : IBM Humor : Assembler-related Humor : VIM Humor : Computer Viruses Humor : Bright tomorrow is rescheduled to a day after tomorrow : Classic Computer Humor
The Last but not Least Technology is dominated by two types of people: those who understand what they do not manage and those who manage what they do not understand ~Archibald Putt. Ph.D
Copyright © 1996-2020 by Softpanorama Society. www.softpanorama.org was initially created as a service to the (now defunct) UN Sustainable Development Networking Programme (SDNP) without any remuneration. This document is an industrial compilation designed and created exclusively for educational use and is distributed under the Softpanorama Content License. Original materials copyright belong to respective owners. Quotes are made for educational purposes only in compliance with the fair use doctrine.
FAIR USE NOTICE This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available to advance understanding of computer science, IT technology, economic, scientific, and social issues. We believe this constitutes a 'fair use' of any such copyrighted material as provided by section 107 of the US Copyright Law according to which such material can be distributed without profit exclusively for research and educational purposes.
This is a Spartan WHYFF (We Help You For Free) site written by people for whom English is not a native language. Grammar and spelling errors should be expected. The site contain some broken links as it develops like a living tree...
|You can use PayPal to to buy a cup of coffee for authors of this site|
Last Modified: March 12, 2019