DNS problem with IP Masq Gateway

DNS problem with IP Masq Gateway

Post by Matthew H » Sat, 23 Jan 1999 04:00:00



My linux gateway with IP masquerade enable has a problem with its DNS
lookup.  I have a LAN with 4 Windoze host machines connected to a linux
gateway with IP masquerade configured.  The hosts work fine with some
applications like Web and ICQ.  However, my linux gateway cannot resolve
internet domain name.  I can resolve names within the LAN thru. the
hosts file.  Everytime i try "ping www.yahoo.com" there is no reply.
when i try "nslookup", i got the following

*** Can't find server name for address xxx.xxx.xxx.xxx: No response from
server.

xxx.xxx.xxx.xxx is the DNS i use for every host machines.

my resolv.conf has the entry

nameserver xxx.xxx.xxx.xxx

and nsswitch.conf

hosts: files dns

looks like resolver cannot talk to the dns i specified.
Please help.

Thanks
Matthew

 
 
 

DNS problem with IP Masq Gateway

Post by David Kirkpatric » Sat, 23 Jan 1999 04:00:00


How are you connected to the net?  Is xxx.xxx.xxx.xxx the
nameserver provided by your ISP?  Are you only local or
even going to an ISP?  What is in hosts, lmhosts and networks?


> My linux gateway with IP masquerade enable has a problem with its DNS
> lookup.  I have a LAN with 4 Windoze host machines connected to a linux
> gateway with IP masquerade configured.  The hosts work fine with some
> applications like Web and ICQ.  However, my linux gateway cannot resolve
> internet domain name.  I can resolve names within the LAN thru. the
> hosts file.  Everytime i try "ping www.yahoo.com" there is no reply.
> when i try "nslookup", i got the following

> *** Can't find server name for address xxx.xxx.xxx.xxx: No response from
> server.

> xxx.xxx.xxx.xxx is the DNS i use for every host machines.

> my resolv.conf has the entry

> nameserver xxx.xxx.xxx.xxx

> and nsswitch.conf

> hosts: files dns

> looks like resolver cannot talk to the dns i specified.
> Please help.

> Thanks
> Matthew

--




 
 
 

DNS problem with IP Masq Gateway

Post by David Moulto » Sat, 23 Jan 1999 04:00:00


...

Quote:> applications like Web and ICQ.  However, my linux gateway cannot resolve
> internet domain name.  I can resolve names within the LAN thru. the
> hosts file.  Everytime i try "ping www.yahoo.com" there is no reply.
> when i try "nslookup", i got the following

> looks like resolver cannot talk to the dns i specified.

Can you ping outside machines using the IP address and not the domain name?
It might be a routing issue.

Also, just a suggestion, I set up my gateway to be a caching DNS as well.
This seems to speed up the lookups at least a little.

dave

 
 
 

DNS problem with IP Masq Gateway

Post by David Kirkpatric » Sat, 23 Jan 1999 04:00:00


The problem is sometimes due to not having your ISP nameserver
specified in /etc/resolv.conf.  See PPP-HOWTO and grep
resolv.conf.
Leave the default route open so PPP0 can use it.  You did not
mention
what your are running RH/Slack... etc or whats in hosts or
networks.
DNS resolution can have an order - its usually something like
hosts,
lmhosts and DNS - wins will be in there if your running MS
machines.
In RH you can specify this order.
d



> ...

> > applications like Web and ICQ.  However, my linux gateway cannot resolve
> > internet domain name.  I can resolve names within the LAN thru. the
> > hosts file.  Everytime i try "ping www.yahoo.com" there is no reply.
> > when i try "nslookup", i got the following

> > looks like resolver cannot talk to the dns i specified.

> Can you ping outside machines using the IP address and not the domain name?
> It might be a routing issue.

> Also, just a suggestion, I set up my gateway to be a caching DNS as well.
> This seems to speed up the lookups at least a little.

> dave

--



 
 
 

DNS problem with IP Masq Gateway

Post by Matthew H » Tue, 26 Jan 1999 04:00:00


Thanks for the reply

I've read the PPP-HOWTO, NET-3-HOWTO, IP-Masq-HOWTO and DNS-HOWTO but i
cannot find a solution.  I am using RedHat 5.2 and using a ppp-on script
to dial out to the internet.  The DNS Ip address i am using is the dns
of my isp and all of my hosts use the same DNS IP which works fine for
them.  I am able to ping internet address by IP but not by name.  My
hosts can ping the internet by both IP and Name.

Here shows some of my files in /etc
--resolv.conf--
nameserver xxx.xxx.xxx.xxx

--hosts--
127.0.0.1       localhost.name.ca  localhost
192.168.0.3     486dx33.name.ca    486dx33
192.168.0.1     matthew.name.ca    matthew
192.168.0.5     earth.name.ca      earth
192.168.0.2     zx6r.name.ca       zx6r  

--networks--
loopback        127.0.0.0
localnet        192.168.0.0  

--nsswitch.conf--
shadow:     files nisplus nis
group:      files nisplus nis

hosts:      files dns

services:   nisplus [NOTFOUND=return] files
networks:   nisplus [NOTFOUND=return] files
protocols:  nisplus [NOTFOUND=return] files
rpc:        nisplus [NOTFOUND=return] files
ethers:     nisplus [NOTFOUND=return] files
netmasks:   nisplus [NOTFOUND=return] files
bootparams: nisplus [NOTFOUND=return] files

netgroup:   nisplus

publickey:  nisplus

automount:  files nisplus
aliases:    files nisplus

--
Thanks,

Matthew


> The problem is sometimes due to not having your ISP nameserver
> specified in /etc/resolv.conf.  See PPP-HOWTO and grep
> resolv.conf.
> Leave the default route open so PPP0 can use it.  You did not
> mention
> what your are running RH/Slack... etc or whats in hosts or
> networks.
> DNS resolution can have an order - its usually something like
> hosts,
> lmhosts and DNS - wins will be in there if your running MS
> machines.
> In RH you can specify this order.
> d



> > ...

> > > applications like Web and ICQ.  However, my linux gateway cannot resolve
> > > internet domain name.  I can resolve names within the LAN thru. the
> > > hosts file.  Everytime i try "ping www.yahoo.com" there is no reply.
> > > when i try "nslookup", i got the following

> > > looks like resolver cannot talk to the dns i specified.

> > Can you ping outside machines using the IP address and not the domain name?
> > It might be a routing issue.

> > Also, just a suggestion, I set up my gateway to be a caching DNS as well.
> > This seems to speed up the lookups at least a little.

> > dave

> --




 
 
 

1. NFS and Samba Problem in IP Masq Gateway

I have a xDSL (1MegModem) access at home and using a RedHat 5.2 Linux
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Masquerade and most of the applications works fine e.g. ICQ, Read_Audio,
HTTP, FTP and Netmeeting (with PhonePatch).  I also use ipportfw to
forward ports to internal Personal Web Servers.  My problem is I cannot
mount the windows harddrives to this Linux box.  I am running NFS Daemon
on my windows machine (I tried several different NFSDs).  

And every time I try
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it returns
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but i try
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it returns
umount: /tmp/linux: not mounted

The problem seems to start when I installed the second Ethernet card for
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Another problem is Samba.  I can access te harddrive of this linux box
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2nd Ethernet card.  I cannot access the drive anymore.  I can't even
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just dead after that (I cannot find it in 'ps aux').

Is there anything wrong would be caused by the setup of this second
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