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Moriah
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PostPosted: Thu Jul 28, 2005 12:37 am    Post subject: /etc/hosts broken Reply with quote

I have installed this system twice this week, and each time, the resolver behaves in a broken way. It can resolve domain names via lookup thru an external name server, but it gets all confused looking up names in /etc/hosts :?:

First, some background:
Code:
ezekiel ~ # uname -a
Linux ezekiel.elilabs.com 2.6.12-gentoo-r6 #1 Wed Jul 27 15:51:38 CDT 2005 i686 AMD Athlon(tm)  AuthenticAMD GNU/Linux
ezekiel ~ #
Code:
ezekiel ~ # cat /etc/resolv.conf
domain elilabs.com
nameserver 198.147.221.34
nameserver 192.107.41.34
nameserver 216.68.4.10
ezekiel ~ #
Code:
ezekiel ~ # cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1       localhost.localdomain   localhost


# static ip addresses on lan -- 192.168.1.0/24
#
192.168.1.1             aaron           aaron.elilabs.com
192.168.1.2             elisha          elisha.elilabs.com
192.168.1.3             ezra            ezra.elilabs.com
192.168.1.4             gabriel         gabriel.elilabs.com
192.168.1.5             lp              lp.elilabs.com
192.168.1.6             abraham         abraham.elilabs.com
192.168.1.7             ruth            ruth.elilabs.com
192.168.1.8             shaphan         shaphan.elilabs.com
192.168.1.9             samuel          samuel.elilabs.com
192.168.1.11            daniel          daniel.elilabs.com
192.168.1.13            ezekiel         ezekiel.elilabs.com

### temporary addresses
#
192.168.1.50            neweli          neweli.elilabs.com


# static ip addresses on dmz -- 192.168.2.0/24
#
192.168.2.1             nehemiah        nehemiah.elilabs.com
#192.168.2.10           urim            urim.elilabs.com
192.168.1.102           urim            urim.elilabs.com
#192.168.2.11           thummim         thummim.elilabs.com
192.168.1.101           thummim         thummim.elilabs.com
192.168.2.13            eli             eli.elilabs.com         www.elilabs.com         elilabs.com
#192.168.1.101          eli             eli.elilabs.com         www.elilabs.com         elilabs.com


# static ip addresses allocated by xnet
#
# our cidr block: 205.243.154.192/28 & 204.248.49.62
#
# xnet servers
#
198.147.221.34          ns1.xnet.com            # nameserver
198.147.221.35          ns2.xnet.com            # nameserver
198.147.221.66          typhoon.xnet.com        # shell
198.147.221.37          flood.xnet.com          # news

# static ip addresses allocated by zoomtown
#
# zoomtown servers
#
216.68.4.10             ns1.zoomtown.com
216.68.5.10             ns2.zoomtown.com
#
# our gateway
#
10.251.36.120           dsl                     dsl.elilabs.com
10.251.36.1             dslam                   dslam.elilabs.zoomtown.com
216.68.54.75            dhcp                    dhcp.elilabs.zoomtown.com


# static ip addresses allocated by iglou
#
64.253.104.156          eli01.cindsl01.iglou.com        # tunnel ppp0 on nehemiah
204.255.233.225         lanadvantage-01.iglou.com       # lac (tunnel server)
64.253.104.1            cindsl01-2.iglou.com            # our gateway to the internet via iglou
#
192.107.41.34           dns1.iglou.com
192.107.41.21           dns2.iglou.com
192.107.41.38           shellaccess.com

#
# our cidr block: 64.253.103.8/29
#
# 64.253.103.8          network
# 64.253.103.9          spare1.elilabs.com
# 64.253.103.10         urim.elilabs.com        ns1.elilabs.com
# 64.253.103.11         thummim.elilabs.com     ns2.elilabs.com
# 64.253.103.12         spare2.elilabs.com
# 64.253.103.13         www.elilabs.com         eli.elilabs.com         elilabs.com
# 64.253.103.14         spare3.elilabs.com
# 64.253.103.15         broadcast

# disable annoying delays on drudge site
127.0.0.2       code.fastclick.net
127.0.0.3       a.tribalfusion.com
127.0.0.4       servedby.advertising.com
127.0.0.5       cserver.mii.instacontent.com
127.0.0.6       media.fastclick.net
ezekiel ~ #
Now some examples of good behavior:
Code:
ezekiel ~ # ping localhost
PING localhost (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.061 ms
64 bytes from localhost (127.0.0.1): icmp_seq=2 ttl=64 time=0.023 ms

--- localhost ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1000ms
rtt min/avg/max/mdev = 0.023/0.042/0.061/0.019 ms
ezekiel ~ # ping ftp.uu.net
PING ftp.uu.net (192.48.96.9) 56(84) bytes of data.
64 bytes from ftp.UU.NET (192.48.96.9): icmp_seq=1 ttl=244 time=102 ms
64 bytes from ftp.UU.NET (192.48.96.9): icmp_seq=2 ttl=244 time=121 ms
64 bytes from ftp.UU.NET (192.48.96.9): icmp_seq=3 ttl=244 time=113 ms

--- ftp.uu.net ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2002ms
rtt min/avg/max/mdev = 102.145/112.576/121.962/8.123 ms
ezekiel ~ # ping forums.gentoo.org
PING forums.gentoo.org (140.211.166.170) 56(84) bytes of data.
64 bytes from dove.gentoo.osuosl.org (140.211.166.170): icmp_seq=1 ttl=49 time=155 ms
64 bytes from dove.gentoo.osuosl.org (140.211.166.170): icmp_seq=2 ttl=49 time=152 ms

--- forums.gentoo.org ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 999ms
rtt min/avg/max/mdev = 152.407/154.113/155.819/1.706 ms
ezekiel ~ #

Now some examples of bad behavior:
Code:
ezekiel ~ # ping ezekiel
ping: unknown host ezekiel
ezekiel ~ # ping elisha
ping: unknown host elisha
ezekiel ~ # ping ezra
PING elilabs.com (64.253.103.13) 56(84) bytes of data.
64 bytes from elijah-5.iglou.com (64.253.103.13): icmp_seq=1 ttl=63 time=2.06 ms

--- elilabs.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 2.066/2.066/2.066/0.000 ms
ezekiel ~ # ping eli
PING elilabs.com (64.253.103.13) 56(84) bytes of data.
64 bytes from elijah-5.iglou.com (64.253.103.13): icmp_seq=1 ttl=63 time=1.72 ms

--- elilabs.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 1.720/1.720/1.720/0.000 ms
ezekiel ~ #
Notice that ezekiel cannot even resolve its own name. It resolves ezra to the wrong ip address -- the same one it correctly resolves eli to.

I have fiddled with this until my patience is exhausted. I have posted for help before, but it took a while to really characterize the total symptom set. At one time, it would not resolve localhost.

After I noticed this weird behaviour on the part of the resolver, I decided that maybe an ebuild was temporarily screwed up, so I reinstalled the system last night and this morning. The new installation produces the same symptoms.

BTW The /etc/hosts and /etc/resolv.conf files were copied from a system that works.

HELP :evil:
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cyrillic
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PostPosted: Thu Jul 28, 2005 12:52 am    Post subject: Re: /etc/hosts broken Reply with quote

Have you tried putting the FQDN before the hostname ?

Like this
Code:
127.0.0.1       localhost.localdomain   localhost


Instead of this
Code:
192.168.1.13            ezekiel         ezekiel.elilabs.com
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ONEEYEMAN
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PostPosted: Thu Jul 28, 2005 12:57 am    Post subject: Reply with quote

Hi, Moriah,
What is you subnet mask? Is it 255.255.255.0? Or 255.255.0.0?
Also what is the output of the "ifconfig eth0"?

Thank you.
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Moriah
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PostPosted: Thu Jul 28, 2005 1:01 am    Post subject: Reply with quote

Regarding the subnetmask:
Code:
ezekiel ~ # ifconfig
eth0      Link encap:Ethernet  HWaddr 00:0D:61:51:E5:87 
          inet addr:192.168.1.13  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1400  Metric:1
          RX packets:29488 errors:0 dropped:0 overruns:0 frame:0
          TX packets:13183 errors:0 dropped:0 overruns:0 carrier:0
          collisions:2 txqueuelen:1000
          RX bytes:5731304 (5.4 Mb)  TX bytes:2759344 (2.6 Mb)
          Interrupt:11 Base address:0xb800

lo        Link encap:Local Loopback 
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:14 errors:0 dropped:0 overruns:0 frame:0
          TX packets:14 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:1176 (1.1 Kb)  TX bytes:1176 (1.1 Kb)

ezekiel ~ #
Regarding reversing the order of the FDQN names and the bare ones, all I can say is that the same /etc/hosts file works on several -- albiet older -- systems. Did they change something recently that reverses the ordering?
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ONEEYEMAN
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PostPosted: Thu Jul 28, 2005 1:06 am    Post subject: Reply with quote

I think that cyrillic is correct.
That's the correct order of the things.

Thank you.
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Moriah
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PostPosted: Thu Jul 28, 2005 1:10 am    Post subject: Reply with quote

Well, I just reversed the order, and it made no difference in the symptoms.
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cyrillic
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PostPosted: Thu Jul 28, 2005 1:13 am    Post subject: Reply with quote

Moriah wrote:
Regarding reversing the order of the FDQN names and the bare ones, all I can say is that the same /etc/hosts file works on several -- albiet older -- systems. Did they change something recently that reverses the ordering?

I don't mess with domains on my own lan, but I read somewhere that the order was significant, and the bare hostname should go last.

ps. I use net-dns/dnsmasq for local DNS and DHCP. I would think with a setup as complicated as yours, something like this would make life easier than having a huge /etc/hosts file.
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Moriah
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PostPosted: Thu Jul 28, 2005 1:16 am    Post subject: Reply with quote

Well, I have been doing it this way for the last 10 years or so, and it worked fine until very recently. In fact, it still does work on most of the systems; its just the new ones (Ihave several with the same problem that were supposed to be "upgrades") that are messed up. Something has definately changed in the domain name resolver, and it sure looks broken to me.
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ONEEYEMAN
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PostPosted: Thu Jul 28, 2005 3:15 am    Post subject: Reply with quote

How do you connecting to the network? Are you using the router, hub or...?
You mentioned that you have other Gentoo boxes thatworks fine. Are they connected to the same network. Can you "ping" from the working PC the ezekiel? Can you ping it by IP address?

Thank you.
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gentoo_dude
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PostPosted: Thu Jul 28, 2005 3:28 am    Post subject: Reply with quote

I would also check that the kernel routes correctly the network
post your
Code:
 route
output
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Moriah
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PostPosted: Thu Jul 28, 2005 3:55 am    Post subject: Reply with quote

Here it is:
Code:
ezekiel ~ # route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.1.0     *               255.255.255.0   U     0      0        0 eth0
127.0.0.0       localhost       255.0.0.0       UG    0      0        0 lo
default         192.168.1.1     0.0.0.0         UG    0      0        0 eth0
ezekiel ~ #
I seem to have determined that the poor system doesn't know its own dnsdomainname, as seen here:
Code:
ezekiel ~ # dnsdomainname
dnsdomainname: Unknown host
ezekiel ~ #
So I am beginning to think that this may be at the root of the problem.

Recently, the use of /etc/hostname and /etc/dnsdomainname has been depricated in preference for /etc/conf.d/hostname and /etc/conf.d/domainname and as far as I can tell, that was the beginning of sorrows. :cry:

Just for the record, here is what is enabled with rc-update:
Code:
ezekiel ~ # rc-update show
            bootmisc | boot                         
             checkfs | boot                         
           checkroot | boot                         
               clock | boot                         
         consolefont | boot                         
          domainname |      default                 
                 gpm |                               
              hdparm |                               
            hostname | boot                         
             keymaps | boot                         
               local |      default nonetwork       
          localmount | boot                         
             modules | boot                         
            net.eth0 |      default                 
              net.lo | boot                         
            netmount |      default                 
                nscd |                               
             numlock |                               
           rmnologin | boot                         
              rsyncd |                               
                sshd |      default                 
           syslog-ng |      default                 
             urandom | boot                         
          vixie-cron |      default                 
ezekiel ~ #
I just can't believe that I am the only person who has seen this. Surely there must be others...
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Moriah
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PostPosted: Thu Jul 28, 2005 4:11 am    Post subject: Reply with quote

In reply to ONEEYEMAN, who said:
Quote:
How do you connecting to the network? Are you using the router, hub or...?
You mentioned that you have other Gentoo boxes thatworks fine. Are they connected to the same network. Can you "ping" from the working PC the ezekiel? Can you ping it by IP address?
You may see how I connect to the network from the diagram at http://www.elilabs.com/elilabs_network.html but to make it short, it is a classic dual firewall with a dmz setup.

I get my connecttion from a cable modem which is in bridge mode and the gateway firewall (running iptables and l2tpd) gets a dynamic ip address from the cable provider's dhcp server. It then uses this address to connect to an L2TP LAC and builds an L2TP tunnel to an ISP that provides me with my CIDR block of static ip addresses for the servers on the dmz. The dmz is static natted by the firewall so that only the firewall's iptables configuration file needs to change if any of the server addresses change.

Also on the dmz is the choke firewall, which is masqueraded behind the gateway firewall to be invisible from the internet. The choke firewall performs a second level of masquerading for the workstations etc. on the lan.

This whole setup works beautifully, except for these 4 new machines, which are all experiencing the same goofy problem; therefore, I know it is not the connection to the internet.

All the machines acting badly are behind the choke firewall. All the other machines working properly are either on the lan, the dmz, or they are one of the two firewalls.

I can ping any of the sick systems from any machine using a numerical ip address, and I can ping from any of the sick boxes to anywhere using a numerical ip address, It is not a network problem; it is a resolver problem. Addresses that are resolved by a true domain name server query work correctly on the sick boxes. It is only addresses in the /etc/hosts file that are messed up.

As I posted above, the sick machines do not know what their domain name is. :o
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dr_walm
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PostPosted: Thu Jul 28, 2005 7:40 am    Post subject: Reply with quote

I hade the same problem but solved it with creating
Code:
/etc/nsswitch.conf

and add
Code:
hosts: files dns

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jmbsvicetto
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PostPosted: Thu Jul 28, 2005 10:58 am    Post subject: Reply with quote

Hi.

In case you're missing the /etc/nsswitch.conf file, here is mine
Code:
atl64 linux # cat /etc/nsswitch.conf
# /etc/nsswitch.conf:
# $Header: /var/cvsroot/gentoo-x86/sys-libs/glibc/files/nsswitch.conf,v 1.1 2005/05/17 00:52:41 vapier Exp $

passwd:      compat
shadow:      compat
group:       compat

hosts:       files dns
networks:    files dns

services:    db files
protocols:   db files
rpc:         db files
ethers:      db files
netmasks:    files
netgroup:    files
bootparams:  files

automount:   files
aliases:     files
atl64 linux #

By the way, the /etc/nsswitch.conf file belongs to the glibc package.
Code:
atl64 linux # equery belongs /etc/nsswitch.conf
[ Searching for file(s) /etc/nsswitch.conf in *... ]
sys-libs/glibc-2.3.5 (/etc/nsswitch.conf)
atl64 linux #

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MickKi
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PostPosted: Thu Jul 28, 2005 12:52 pm    Post subject: Reply with quote

Hi Moriah,

Not sure if this helps, but since you are referring to recent changes . . . the /etc/hostname and /etc/dnsdomainname files have been replaced by /etc/conf.d/hostname and /etc/conf.d/domainname, after baselayout-1.11.12-r4. You'll need to rename/move/delete the old files after you have made the appropriate entries in the new ../conf.d/ equivalents.
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vthokiestm
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PostPosted: Thu Jul 28, 2005 5:41 pm    Post subject: Reply with quote

I'm having the same problem. I just upgraded my system and I can no longer resolve any name in /etc/hosts.
It's like /etc/hosts is being completely ignored.

Updating /etc/nsswitch didn't help either.
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TreeFree
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PostPosted: Thu Jul 28, 2005 9:29 pm    Post subject: Thanks jorge & dr_walm Reply with quote

I just did a fresh install and found out I was infact missing /etc/nsswitch.conf file too which was not allowing localhost to be resolved. I created the file and copied in the contents that jorge posted and I'm back in business. Thanks!! :D
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PostPosted: Thu Jul 28, 2005 10:52 pm    Post subject: Reply with quote

Glad to help.
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tosk
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PostPosted: Sun Jul 31, 2005 3:27 am    Post subject: Reply with quote

I also was having this problem and the nsswitch.conf solution solved the problem.
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gmtl3
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PostPosted: Mon Aug 01, 2005 10:35 pm    Post subject: Reply with quote

For what it's worth. I was having a similar problem, with "search" and "domain" statement conflicts in /etc/resolv.conf preventing non-FQND entries for local domain to not get resolved for things like ping/ssh/etc. Simply making sure the "domain" statement was above the "search" statement fixed it.

Hope this helps someone else.
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PostPosted: Tue Aug 02, 2005 7:33 am    Post subject: Reply with quote

Moved from Installing Gentoo to Networking & Security.
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Larde
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PostPosted: Tue Aug 02, 2005 11:46 am    Post subject: Reply with quote

gmtl3 wrote:
[...] I was having a similar problem, with "search" and "domain" statement conflicts in /etc/resolv.conf[...] Simply making sure the "domain" statement was above the "search" statement fixed it.

Hope this helps someone else.


Well, what you wanted to say is: Use either the "search" or the "domain" statement. There can only be one... :-)

Or as the manpage calls it:
Code:

   The  domain  and search keywords are mutually exclusive.  If more than one instance of these keywords
   is present, the last instance wins.


Or, as a better, non-gentoo manpage calls it:
Code:

   A search entry defines the list of domains to search when resolving a name. Only one domain
   entry or search entry can be used. If the domain entry is used, the default search list is
   the default domain. A search entry should be used when a search list other than the default
   is required. The entry is of the form:

   search DomainName ...

   The search entry can have up to a maximum of 1024 characater strings for the DomainName variable.
   The first DomainName variable is interpreted as the default domain name.

   The domain entry and search entry are mutually exclusive. If both entries are used, the one that
   appears last will override the other.


Just to be nitpicking... ;-)


Yours,
Larde
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mfairchi
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Joined: 23 Apr 2002
Posts: 57
Location: Ventura, California

PostPosted: Thu Aug 04, 2005 6:50 am    Post subject: worked for me Reply with quote

I was having basicly the same probelm.
somehow /etc/nsswitch.conf had
hosts: files wins

I changed it to
hosts: files dns

now everything works fine
:)
thanks,
Michael
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vthokiestm
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Joined: 21 Jan 2004
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PostPosted: Mon Aug 08, 2005 5:24 pm    Post subject: /etc/nsswitch.conf must be user readable Reply with quote

Finally figured this out. Users couldn't read /etc/nsswitch.conf.

I fixed my machine with...

Code:
chmod 644 /etc/nsswitch.conf


...and everything is working now!!!
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