Newsgroups: gmane.linux.debian.user Date: Wed, 24 May 2006 17:54:04 +0200
Newsgroups: gmane.linux.debian.user Date: Wed, 24 May 2006 17:54:04 +0200
> My crabby ISP is so screwed up, that I need 4 or more seconds to resolve > google.com, and many time I would get "domain name not found" right in > the middling while I'm looking my yahoo email. It's no use complaining > to my ISP. I just installed the DNS cache server. > > The problem is it won't be long before my etc/resolv.conf, which points > to my own DNS cache server, get changed. How can I solve that? Is there > any hooks like ipup(?) for dial up?
You might want to look at the "resolvconf" package.
George Borisov
> The problem is it won't be long before my etc/resolv.conf, which points > to my own DNS cache server, get changed. How can I solve that? Is there > any hooks like ipup(?) for dial up?
if you use pump for a dhcp client, there are a couple of ways to tell it not to update the DNS resolver configuration (add '-d' in the init script, or even better put 'device eth0 { nodns }' in pump.conf)
if you don't use pump, you can either look for a similar feature in your dhcp client or simply 'apt-get install pump' (it will replace your current client)
Joris
> if you use pump for a dhcp client, there are a couple of ways to tell it
> not to update the DNS resolver configuration (add '-d' in the init
> script, or even better put 'device eth0 { nodns }' in pump.conf)
And if you are using dhclient you can add the following line to your /etc/dhclient.conf
supersede domain-name-servers 127.0.0.1;
"man dhclient.conf" for more details
Ken Wahl
dhclient-script provides the enter and exit hooks for local customizations to to override the default behaviour of the client in creating a /etc/resolv.conf file.
After all processing has completed, /etc/dhclient-script checks for the presence of the /etc/dhclient-exit-hooks script, which if present is invoked using the '.' command.
Newsgroups: gmane.linux.debian.user Date: Fri, 06 Oct 2006 18:16:28 +0100
> > Also, eveytime I change resolv.conf it gets changed back to something > > else... > > I think he means that his resolv.conf gets overwritten by the information > provided by the dhcp server as discussed here (with solution): > > http://forums.debian.net/viewtopic.php?t=7239[]
in short, he probably needs in /etc/dhclient.conf
prepend domain-name-servers 127.0.0.1;
and perhaps also
supersede domain-name "mydomain.tld";
they should already be in there commented out, just needs to uncomment and put in correct data.
Richard Lyons
AUTHORS
v.<1.3
Yoichi Hariguchi <yoichi@fore.com>
v.1.3
Sergei Viznyuk <sv@phystech.com>
dhcpcd -k ifconfig eth0 down dhcpcd $ route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 131.162.160.0 * 255.255.248.0 U 0 0 0 eth0 loopback * 255.0.0.0 U 0 0 0 lo default vlan-160.acadia 0.0.0.0 UG 0 0 0 eth0
/etc/dhcpc/dhcpcd-eth0.info
dhcpcd -k # in /sbin
ifconfig eth0 down
dhcpcd
?
ifconfig eth0 131.162.131.132 broadcast 131.162.167.255 netmask 255.255.248.0
route # in /sbin
route add default gw 131.162.128.1 netmask 0.0.0.0 metric 1
route add -net 131.162.160.0 netmask '255.255.248.0' dev eth0 route add -net default gw 131.162.160.1 netmask '0.0.0.0' dev eth0
dhcpcd - a wrapper for the DHCP client daemon.
In Debian, the DHCP client daemon binary is called dhcpcd-bin and it is invoked via a wrapper called dhcpcd. Dhcpcd is normally invoked by ifup(8) but ifup only allows the setting of a limited number of dhcpcd command line flags. The dhcpcd wrapper reads extra flags from /etc/dhcpc/config and then invokes dhcpcd-bin(8) It also adds the hostname as an argument to the command line, unless it is already set by ifup or /etc/dhcpc/config or SET_HOSTNAME is configured. In that case there is no point in sending the old hostname with the DHCP request when it will be overridden by a new name supplied by the DHCP server.
Version: 1:2.0.3-1
dhcpcd [-dknoprBCDHNRSTY] [-t <timeout>] [-c <ExecFilePath>]
[-h <hostname>] [-i <vendorClassID>] [-I <clientID>]
[-l <leasetime>] [-s [ipaddr]] [-F none|ptr|both] [-G [gateway]]
[-w <windowsize>] [-L <ConfigDir>] [-e <etcDir>]
[-m <routeMetric>] [interface]
It gets the host information (IP address, netmask, broadcast address, etc.) from a DHCP server and configures the network interface of the machine on which it is running. It also tries to renew the lease time according to RFC2131.
V: dhcpcd 2.0, 20 July 2005
/etc/dhcpc/dhcpcd.exe
script file, which dhcpcd will try to execute whenever it con-
figures or brings down the interface. The path to this exe-
cutable script can be changed with -c <ExecFilePath> option.
Dhcpcd passes 3 parameters to dhcpcd.exe script:
dhcpcd.exe <HostInfoFilePath> <up|down|new> [-d]
The first parameter <HostInfoFilePath> is path to dhcpcd-<inter-
face>.info file. The word <interface> is actually replaced with
interface name dhcpcd is attached to, e.g. "eth0". The second
parameter values <up|down|new> mean the interface has been
brought up with the same IP address as before ("up"), or with
the new IP address ("new"), or the interface has been brought
down ("down"). Parameter -d is passed in a case dhcpcd has been
started with -d debug flag.
documented on: 2006.07.22
DHCP Client
This is a split off from the dhcp package and contains the DHCP client tools.
Tag: interface::commandline, network::configuration, protocol::dhcp, protocol::ip, role::sw:client, use::configuring
This is the DHCP client from version 2 of the Internet Software Consortium DHCP package. For more information visit the ISC web site at http://www.isc.org.
head -5 /etc/dhcpc/dhcpcd-eth0.info
and put it into /etc/rc.d/rc.inet1, then set
DHCP="no" # Use DHCP ("yes" or "no")
The will achieve the same result of a serious Q&A of command 'netconfig'.
set
DHCP="yes"
#! /bin/sh # rc.inet1 This shell script boots up the base INET system. HOSTNAME=`cat /etc/HOSTNAME` # Attach the loopback device. /sbin/ifconfig lo 127.0.0.1 /sbin/route add -net 127.0.0.0 netmask 255.0.0.0 lo # IF YOU HAVE AN ETHERNET CONNECTION, use these lines below to configure the # eth0 interface. # Edit these values to set up a static IP address: IPADDR="131.162.131.132" # REPLACE with YOUR IP address! NETMASK="255.255.248.0" # REPLACE with YOUR netmask! NETWORK="131.162.128.0" # REPLACE with YOUR network address! BROADCAST="131.162.135.255" # REPLACE with YOUR broadcast address, if you # have one. If not, leave blank and edit below. GATEWAY="131.162.128.1" # REPLACE with YOUR gateway address! # To use DHCP instead of a static IP, set this value to "yes": DHCP="yes" # Use DHCP ("yes" or "no") # OK, time to set up the interface: if [ "$DHCP" = "yes" ]; then # use DHCP to set everything up: echo "Attempting to configure eth0 by contacting a DHCP server..." /sbin/dhcpcd elif [ ! "$IPADDR" = "127.0.0.1" ]; then # set up IP statically: # Set up the ethernet card: echo "Configuring eth0 as ${IPADDR}..." /sbin/ifconfig eth0 ${IPADDR} broadcast ${BROADCAST} netmask ${NETMASK} # If that didn't succeed, give the system administrator some hints: if [ ! $? = 0 ]; then cat << EOF Your ethernet card was not initialized properly. Here are some reasons why this may have happened, and the solutions: 1. Your kernel does not contain support for your card. Including all the network drivers in a Linux kernel can make it too large to even boot, and sometimes including extra drivers can cause system hangs. To support your ethernet, either edit /etc/rc.d/rc.modules to load the support at boottime, or compile and install a kernel that contains support. EOF fi # Older kernel versions need this to set up the eth0 routing table: KVERSION=`uname -r | cut -f 1,2 -d .` if [ "$KVERSION" = "1.0" -o "$KVERSION" = "1.1" \ -o "$KVERSION" = "1.2" -o "$KVERSION" = "2.0" -o "$KVERSION" = "" ]; then /sbin/route add -net ${NETWORK} netmask ${NETMASK} eth0 fi # If there is a gateway defined, then set it up: if [ ! "$GATEWAY" = "" ]; then /sbin/route add default gw ${GATEWAY} netmask 0.0.0.0 metric 1 fi fi # End of rc.inet1
pump
% pump -s
Device eth0
IP: 192.168.2.12
Netmask: 255.255.255.0
Broadcast: 192.168.2.255
Network: 192.168.2.0
Boot server 192.168.2.1
Next server 0.0.0.0
Gateway: 192.168.2.1
Gateways: 192.168.2.1
Hostname: cxmr.dyndns.org
Domain: no-domain-set.bellcanada
Nameservers: 192.168.2.1 192.168.2.1
Renewal time: Tue Oct 31 22:44:11 2006
Expiration time: Wed Nov 1 00:14:11 2006
% pump -i eth0 --status
Device eth0
IP: 192.168.2.12
Netmask: 255.255.255.0
Broadcast: 192.168.2.255
Network: 192.168.2.0
Boot server 192.168.2.1
Next server 0.0.0.0
Gateway: 192.168.2.1
Gateways: 192.168.2.1
Hostname: cxmr.dyndns.org
Domain: no-domain-set.bellcanada
Nameservers: 192.168.2.1 192.168.2.1
Renewal time: Tue Oct 31 22:44:11 2006
Expiration time: Wed Nov 1 00:14:11 2006
$ pump pump: must be run as root
NAME
pump - configure network interface via BOOTP or DHCP protocol
DESCRIPTION
pump is a daemon that manages network interfaces that are controlled
by either the DHCP or BOOTP protocol.
Once pump is managing an interface, you can run pump to query the status of that interface. For example, /sbin/pump -i eth0 --status will print the current status of device eth0.
COMMAND-LINE OPTIONS
switch long option description
-h --hostname=hostname Hostname to request
-i --interface=iface Interface to configure (normally eth0)
-k --kill Kill daemon (and disable all interfaces)
-r --release Release interface
-R --renew Force immediate lease renewal
-s --status Display interface status
-? --help Show this help message
--usage Display brief usage message
LOGGING
Pump logs a good deal of information to syslog, much of it at the
DEBUG level. If you're having trouble, it's a good idea to turn up
syslog's logging level.
killall dhclient
# -- otherwise there would be multi-instances of dhclient which will
cause trouble. (two lease in /var/state/dhcp/dhclient.leases)
ifconfig eth0 down
dhclient
or,
dhclient eth0
ifconfig
$ cat /var/lib/dhcp/dhclient.leases
lease {
interface "eth0";
fixed-address 192.168.0.255;
option subnet-mask 255.255.255.0;
option time-offset -18000;
option routers 192.168.0.1;
option dhcp-lease-time 21600;
option dhcp-message-type 5;
option domain-name-servers 192.168.0.1;
option dhcp-server-identifier 192.168.0.100;
option nis-domain "domain.org";
option domain-name "domain.org";
renew 5 2002/12/13 06:44:25;
rebind 5 2002/12/13 09:07:10;
expire 5 2002/12/13 09:52:10;
}
cat /var/state/dhcp/dhclient.leases
documented on: 2000.10.15 Sun 00:41:40
Newsgroups: comp.os.linux.misc,comp.os.linux.redhat,linux.redhat.misc
> - Can anyone tell me where is the DHCP configuration file? I tried to look > for /etc/dhcpc and /etc/dhcpcd
Are you using dhcpcd or pump or something else? There isn't really any DHCP configuration file, as that would defeat the whole point of DHCP, which is that you don't have to go configure every machine! The way DHCP works is basically that the client shouts onto the Ethernet:
Help! I need an address! And the server replies: How about this one? Sure, that one sounds good. May I have it? Here you go, and here's the other stuff that goes with it.
As you can see, there isn't much configuring that _could_ be done on the client side. If you just want more verbose logging, you can use "dhcpcd -d", which produces debugging output. If you're using pump, I don't know, but the man page should be able to tell you.
JDW
$ grep DHCP_HOSTNAME /etc/sysconfig/network-scripts/ifup
if [ -n "${DHCP_HOSTNAME}" ]; then
PUMPARGS="-h ${DHCP_HOSTNAME}"
DHCPCDARGS="-h ${DHCP_HOSTNAME}"
/etc/sysconfig/network-scripts/ifup in Rh7.2 will default load dhcpcd first. Pump is used only when dhcpcd is not installed.
Newsgroups: comp.os.linux.misc
> tell me how to switch PUMP to DHCPCD?
It's as simple as un-installing pump and installing dhcpcd. The ifup script will try both.
Tony Lill
Take a look at the book "Linux Firewalls" by Robert L. Ziegler, New Riders, page 425 - 432. He gives a good description of switching from pump to dhcpcd.
I just switched to dhcpcd myself from pump because I'm using an internet firewall with web services (Apache, wu-ftp, etc, etc) with a dynamic IP (rather than static) IP address. As a consequence I need dhcpcd to run the firewall script again any time the ip address changes.
Some things to consider:
"pump" is used in Redhat 6.0 and beyond. "dhcpcd" was used in pre-6.0.
dhcpcd is included in the Redhat distribution even though it's not used, (ie: an RPM).
To install I would first manually create /etc/dhcpc, then install. Next I would place any scripts for dhcpcd to run in /etc/dhcpc/dhcpcd-eth0.exe, (this is not an executable, it is a bash script you create from scratch! Replace "eth0" with whatever your interface is, though I never had any luck with "ppp0".
Now type /sbin/dhcpcd and you will get an ip address assigned. Type "/sbin/dhcpcd -k" to shut down dhcpcd. It will leave your eth0 down, so when done you have to do "ifup eth0".
Apparently the current version of dhcpcd doesn't run the /etc/dhcpc/dhcpcd-eth0.exe bash script if the new IP address assignment is the same as the old IP address. Older versions of dhcpcd ran the script even when the IP didn't change.
In Redhat 6.0 (and possibly other versions) where pump is used you may want to modify /sbin/ifup to use dhcpcd rather than pump, for example
if [ -n "$PUMP" ]; then
echo -n "Determining IP information for $DEVICE..."
if /sbin/dhcpcd; then
/etc/rc.d/init.d/myfirewallbashscript
else
echo "failed."
exit 1
fi
else ...
Tom
'dhcpcd': (dynamic host configuration protocol client daemon)
'dhcpd' (dynamic host configuration protocol daemon).
rpm -e pump rpm -q pump psbn pump
rpm -ivv dhcpcd-1.3.18pl3-1.i386.rpm rpm -qil dhcpcd
dhcpcd ifconfig head -5 /etc/dhcpc/dhcpcd-eth0.info cat /etc/resolv.conf
AOK.
$ type netconfig netconfig is /usr/sbin/netconfig
$ file /usr/sbin/netconfig /usr/sbin/netconfig: ELF 32-bit LSB executable, Intel 80386, version 1, dynamically linked (uses shared libs), stripped
Netconfig will ask a series of questions of network configuration(no card).
netconf is actually a symbolic link to linuxconf, which limits linuxconf for only network configuaration task (card & env).
$ type netconf netconf is /sbin/netconf
$ ls /sbin/netconf lrwxrwxrwx 1 root root /sbin/netconf -> linuxconf*