I avoid the problem of a separate /etc/resolv.conf for each of my ISP's
by never using my ISP's DNS servers.
I found that DNS lookups to my local ISP took as long as lookups to the
the main internet DNS servers A through M, about 4 seconds.
So, I run a local DNS server, and I have but one entry
in my /etc/resolv.conf,
nameserver 192.168.1.1
If you have but one local computer, you could use the default
nameserver 127.0.0.1
Again, in this file, I have no ISP nameservers.
This neatly solves the problem with ISP nameservers,
but you need local DNS with more than just caching.
For DNS, the debian package "bind" installed /var/named/named.root,
which includes the internet's main DNS servers A through M.
While the documentation on using the "bind" package was not clear,
intuition takes you a long way [I spent about 10 hours mulling
over what to do with DNS; I would like to see more suggestions in
README.debian files with each package, perhaps what the package
maintainer does with it].
I use the debian ppp package version 2.3.6-2, so rather
than make my own ip-up file, I put files (without a decimal,
eg, ignored are the files up-mail.old) in /etc/ppp/ip-up.d.
Actually, I have but one file there, the further below file
/etc/ppp/ip-up.d/dns-mail-news-time_jameson .
For me, depending on my ISP, this file mostly handles differences
for mail-user-agents and mail-transfer-agents.
>From this "dns-mail-news-time_jameson" file,
you can infer how you could alter /etc/resolv.conf
according to your current ISP.
Following somebody else's lead, since I run a local DNS server,
I have two separate files
/var/named/named.root.real
/var/named/named.root.fake
according as I have a ppp connection or
as I do not have a ppp connection.
#!/bin/bash
# BEGINNING OF /etc/ppp/ip-up.d/dns-mail-news-time_jameson .
# Some first line like the above is obligatory for run-parts.
# This files controlling program, /etc/ip-up, sets the following
# alpha-numberic variables,
# PPP_IFACE
# PPP_TTY
# PPP_SPEED
# PPP_LOCAL #LOCAL IP ADDRESS, NEEDED FOR DYNAMIC PPP
# PPP_REMOTE
# PPP_IPPARAM
#
# Here, I copy needed configuration files depending on my ISP mnsinc.com
# or pressroom.com.
#
# You probably also want to
# "cp /etc/resolv.conf.connected /etc/resolv.conf here;
# I think not anymore, though maybe copy some named configuration files\
# when go down.
# "knews" will not over-ride the environment variable NNTP,
# but has news.mnsinc.com in /usr/X11R6/lib/X11/app-defaults/Knews.
#
# For testing,
echo $PPP_IFACE $PPP_TTY $PPP_SPEED $PPP_LOCAL $PPP_REMOTE \
>/tmp/ip-up.d.dns-mail.out
case "$PPP_REMOTE" in
206.239*|206.55*)
###This is my ISP mnsinc.com.
##/bin/cp /etc/named.conf.mnsinc-version \
# /etc/named.conf #used by "named" DNS; \
# I no longer use forwarders though
##/bin/cp /var/named/boot.options.mnsinc-version \
# /var/named/boot.options #used by "named" DNS; \
# I no longer use forwarders though
#
/bin/ln -fs /etc/mailname.mnsinc-version \
/etc/mailname #used by pine for outgoing addresses.
/bin/ln -fs /etc/smail/config.mnsinc-version \
/etc/smail/config #for outgoing mail
/bin/ln -fs /etc/nmh/mts.conf.mnsinc-version \
/etc/nmh/mts.conf #for mh MUAs to give correct \
#"SENDER:[EMAIL PROTECTED]" and possibly "From:".
/bin/ln -fs /etc/news/server.mnsinc-version \
/etc/news/server #News server, probably only \
#referenced via my bash, though post-installed by knews.
# logger "working with mnsinc.com" \
#used for debugging this script.
;;
198.69.131*)
###This is my ISP pressroom.com.
##/bin/cp /etc/named.conf.pressroom-version \
## /etc/named.conf #used by "named" DNS; \
## I no longer use forwarders though.
##/bin/cp /var/named/boot.options.pressroom-version \
## /var/named/boot.options #used by "named" DNS;\
## I no longer use forwarders though.
#
/bin/ln -fs /etc/mailname.pressroom-version \
/etc/mailname #used by pine for outgoing addresses.
/bin/ln -fs /etc/smail/config.pressroom-version \
/etc/smail/config #for outgoing mail
/bin/ln -fs /etc/nmh/mts.conf.pressroom-version \
/etc/nmh/mts.conf #for mh MUAs giving correct \
#"SENDER:[EMAIL PROTECTED]" and possibly "From:".
/bin/ln -fs /etc/news/server.pressroom-version \
/etc/news/server #News server, probably only \
#referenced via my bash, though post-installed \
#by knews.
# logger "working with pressroom.com" \
#used for debugging this script.
;;
*)
logger '/etc/ppp/ip-up: Oh no! Can not recognize \
the IP address of the now connected ISP provider.'
;;
esac
# IP-MASQUERADING:
# re-run the following, which clears and resets ip-masquerading,
# using the new PPP_LOCAL (local ppp interface's ip address).
/etc/rc.boot/ipmasq
# DNS (IP) LOOKUP DAEMON:
/bin/ln -fs /var/named/named.root.real /var/named/named.root
# The following starts named from bind package for DNS.
# You can check that "named" works well by the speed of "nslookup ...".
#/usr/sbin/named
/usr/sbin/ndc restart
# MAIL OUTGOING:
/usr/bin/runq #Send pending mail.
# TIME SETTING:
# According to the man pages, the following ntpdate will have no effect
# if the daemon xntpd already runs;
# so I shouldn't run xntpd at startup from /etc/init.d/xntp3.
# When I ran under UTC, if I ran Microsoft NT, the time was off by 5
# hours [England - East Coast time];
# when I booted into Linux, the time was off by 1 hour
# [this was probably the Linux kernel handling daylight savings time];
# when I ran ntpdate, the time became correct.
# Consequently, because my wife uses NT,
# I accomodate NT by not running in UTC time but rather running
# in local time.
# In ip-down, I set the hardware clock and /etc/adjtime with
# /sbin/hwclock --set --date="`/bin/date`"
/usr/sbin/ntpdate -t 8 -b -s black-ice.cc.vt.edu ntp.css.gov \
louie.udel.edu #Set the date now (xntpd will not change \
#time if greater than, for example, 45 minutes).
/usr/sbin/xntpd #Continuously change the date;
#This once ran on boot from within /etc/init.d/xntp3
# GET A BACKGROUND WEATHER MAP
lynx -source http://weather.yahoo.com/graphics/satellite/east_usa.jpg \
>/var/tmp/satmap.jpg
# ENDING OF /etc/ppp/ip-up.d/dns-mail-news-time_jameson
--
Jim Burt, NJ9L, Fairfax, Virginia, USA
[EMAIL PROTECTED] http://www.mnsinc.com/jameson
[EMAIL PROTECTED] (703) 235-5213 ext. 132 (work)
"A poor man associating with a rich man will soon be too poor
to buy even a pair of breeches." --Chinese Proverb
