DNS works, but get 'no route to host' for everything.

DNS works, but get 'no route to host' for everything.

Post by Hank Jansse » Sun, 17 Jan 1999 04:00:00



Greetings all,

I am having a perplexing problem with one part of my PPP setup. I have
setup my PPP to my ISP okay, and everything works (including IP masqueing).
I can connect to the outside world without any problems. (This is done with
the help of dynamic IP)

Now, I was also trying to set this up so I can connect to my work
machines. This is a very large network, (this is done with the help of a
static IP adress assigned to me by my employer.)   I have added the DNS
name servers to my resolv.conf file. And dialing out works just great. But
that is where it stops pretty much.   When I do a ping to a system on my
employers network by name it goes out and seems to look up the IP adress
just fine, eg;

           $ ping system.on.employer.network
           PING system.on.employer.network (XXX.YYY.ZZZ.OOO): 56 data bytes

The XXX.YYY.ZZZ.OOO, is correct. And was correct for all names that I tried
for systems on my employers network. But than ping locks up. When I try to
use telnet to get to those systems I get a;

           No Route To Host.

Using tcpdump gives me pretty much an icmp message stating that what I want
to contact is unreachable. But I do see in the tcpdump messages that my
system is sending the IP adress assigned to me by my employer.

I get this for both the name or the direct IP adress.

Route for both connections gives me;

[The names have been changed to protect the innocent.]

THIS ONE WORKS OKAY, MY NORMAL ISP.

[root /etc]# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
MY.ISP          *               255.255.255.255 UH     1500 0          0 ppp0
192.168.1.0     *               255.255.255.0   U      1500 0          0 eth0
loopback        *               255.0.0.0       U      3584 0          0 lo
default         MY.ISP          0.0.0.0         UG     1500 0          0 ppp0

THIS ONE DOES NOT, MY WORK.  (Yet, it looks the same as my ISP one)

[root /etc]# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
MY.WORK         *               255.255.255.255 UH    0      0        0 ppp0
192.168.1.0     *               255.255.255.0   U     0      0       16 eth0
loopback        *               255.0.0.0       U     0      0       21 lo
default         MY.WORK         0.0.0.0         UG    0      0       16 ppp0

I have tried to change my default gateway to the IP adress that my employer
gave me, and that did not make  any difference.  I have changed the GATEWAY
field in /etc/sysconfig and rebooted, and that did not make any difference
either.

So at this  point I am very confused  and have no idea  what else might  be
wrong.  Does anybody have any idea's???

Oh yes, this of course seems to work just fine in winblows...

Thanks for all help,

Hank.

-------------------------- http://www.anteus.com ---------------------------
Hank Janssen.                       | In order to keep a true perspective of
Anteus Ltd. Seattle                 | one's importance, everyone should have

 
 
 

DNS works, but get 'no route to host' for everything.

Post by Brian McCaule » Mon, 18 Jan 1999 04:00:00



> I am having a perplexing problem with one part of my PPP setup. I have
> setup my PPP to my ISP okay, and everything works (including IP masqueing).
> I can connect to the outside world without any problems. (This is done with
> the help of dynamic IP)

> Now, I was also trying to set this up so I can connect to my work
> machines. This is a very large network, (this is done with the help of a
> static IP adress assigned to me by my employer.)

If this address correctly getting assigned to the ppp0 interface?  If
not then this would explain your problem.

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 ###LL  LL\\ (Brian McCauley)  |

 
 
 

DNS works, but get 'no route to host' for everything.

Post by David Kirkpatric » Fri, 22 Jan 1999 04:00:00


Hank,
   Who exactly is in your resolv.conf?  Also what is in
/etc/hosts,
/etc/networks and /etc/sysconfig/network-scripts/ipcfg-*?  I have
about the same setup.  A few hosts with an NT router with a Linux
box running PPP and masquerading.  Connected to the NT box is
another
network.  All machines DNS entries point to the ISP's dns
numbers.
The other hosts on my networks are defined in hosts and lmhosts.
Every
one can ping and lookup by name but it happend differently under
different circumstances.  Do you have WINS enabled on the MS
machines?
But what exactly is your setup?  Who gets the static ip from the
work network.  Is it the linux box or a router in between?  What
are these machines dns entries?  
   The process for DNS resolution on RH is selectable but most
machines default to something like wins, hosts, dns.  Depending
on
whats in hosts and if static routes were added to wins you will
get
varying results.  What has been done on your systems?  You did
not
mention which ip addressses your working with or what the network
topography was or what addresses were in resolv.conf.  It would
be
helpful to have them.
    When things are working right you can watch with tcpdump arp
getting things square and the networks come up.  
"Who has xxxx.xxx.xx tell yyy.yyy.yy" then the reply from
xxxx.xxx.xx
with its mac address.  Have linux up and watching eth0 then boot
the other machines and see who can report into linux.
David Kirkpatrick

> I am having a perplexing problem with one part of my PPP setup. I have
> setup my PPP to my ISP okay, and everything works (including IP masqueing).
> I can connect to the outside world without any problems. (This is done with
> the help of dynamic IP)

> Now, I was also trying to set this up so I can connect to my work
> machines. This is a very large network, (this is done with the help of a
> static IP adress assigned to me by my employer.)   I have added the DNS
> name servers to my resolv.conf file. And dialing out works just great. But
> that is where it stops pretty much.   When I do a ping to a system on my
> employers network by name it goes out and seems to look up the IP adress
> just fine, eg;

>            $ ping system.on.employer.network
>            PING system.on.employer.network (XXX.YYY.ZZZ.OOO): 56 data bytes

> The XXX.YYY.ZZZ.OOO, is correct. And was correct for all names that I tried
> for systems on my employers network. But than ping locks up. When I try to
> use telnet to get to those systems I get a;

>            No Route To Host.

> Using tcpdump gives me pretty much an icmp message stating that what I want
> to contact is unreachable. But I do see in the tcpdump messages that my
> system is sending the IP adress assigned to me by my employer.

> I get this for both the name or the direct IP adress.

> Route for both connections gives me;

> [The names have been changed to protect the innocent.]

> THIS ONE WORKS OKAY, MY NORMAL ISP.

> [root /etc]# route
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
> MY.ISP          *               255.255.255.255 UH     1500 0          0 ppp0
> 192.168.1.0     *               255.255.255.0   U      1500 0          0 eth0
> loopback        *               255.0.0.0       U      3584 0          0 lo
> default         MY.ISP          0.0.0.0         UG     1500 0          0 ppp0

> THIS ONE DOES NOT, MY WORK.  (Yet, it looks the same as my ISP one)

> [root /etc]# route
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
> MY.WORK         *               255.255.255.255 UH    0      0        0 ppp0
> 192.168.1.0     *               255.255.255.0   U     0      0       16 eth0
> loopback        *               255.0.0.0       U     0      0       21 lo
> default         MY.WORK         0.0.0.0         UG    0      0       16 ppp0

> I have tried to change my default gateway to the IP adress that my employer
> gave me, and that did not make  any difference.  I have changed the GATEWAY
> field in /etc/sysconfig and rebooted, and that did not make any difference
> either.

> So at this  point I am very confused  and have no idea  what else might  be
> wrong.  Does anybody have any idea's???

> Oh yes, this of course seems to work just fine in winblows...

> Thanks for all help,

> Hank.

> -------------------------- http://www.anteus.com ---------------------------
> Hank Janssen.                       | In order to keep a true perspective of
> Anteus Ltd. Seattle                 | one's importance, everyone should have


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