# Can ping router/firewall can't reach internet?

## Dazza

Hi All

I'm having some rather strange problems.  I had installed gentoo without any  probs at all. Good Work guys. Was able to reach internet no problem and was rather impresed with gentoo esp with the junk machine that I'd set up.

Anyway, my joy turned to confusion as all of a sudden I couldn't access the internet. Not too good. I had just installed apache2 and perl and compiled up an app that I was interested in. Anyway all was working merrily and machines  within our small network could access the webpages etc. The I decided to emerge some other stuff and realised I couldn't. Then the fiasco began!

Checked and rechecked my /etc/conf.d/net and it seems to be correct:-

iface_eth0=10.1.0.20 broadcast 10.1.255.255 netmask 255.255.0.0

at the bottom

gateway="eth0/10.1.0.1"

Which is ok?

My resolv.conf

contains

domain Blah.blah

nameserver 194.73.82.242

nameserver 10.1.0.1

Now this resolv.conf does seem to cause a problem. When I have the above included it takes an age for netstat -r to return. When I remove  the nameserver additions it flies.

Also don't like to say it but when I run it on a windows machine on the same network it is also fast.

As I mentioned earlier I can ping the gateway from the gentoo machine. So basically I'm lost. Oh, I also recompiled the kernel to get rid of the ipv6 module with not luck.

Please, please help.

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## smart

Hiya.

Don't worry about slow response from netstat -r. Have the same behaviour for ages but not a problem either. Strange but harmless probably.

From the IP of your machine and your GW i suspect that you actually subnetted 10.x.x.x down to a /24 network, not /16. That is your netmask should possibly be 255.255.255.0 with your router and your box sitting in 10.1.0.x. That would turn your broadcast address to 10.1.0.255 and possibly only now allow for resolving your box's Ethernet address aka MAC.

So try that.

Otherwise, give us a glimpse at the result of relevant parts of

ipconfig /all

on your M$ installation.

After all, try

host www.gentoo.org

to let us understand if DNS really works.Last edited by smart on Wed Dec 10, 2003 12:59 pm; edited 1 time in total

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## bmichaelsen

```
nameserver 194.73.82.242 
```

do you have a route to this nameserver???

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## smart

 *bmichaelsen wrote:*   

> 
> 
> ```
> nameserver 194.73.82.242 
> ```
> ...

 

hmmmm... aka gateway ?

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## NeddySeagoon

Dazza,

Post the result of /sbin/route -n

NeddySeagoon

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## Dazza

Heres the ifconfig for my windows machine.

I tried changing the netmask and broadcast address as suggested but it didn't make a difference.

Ethernet adapter Local Area Connection:

        Connection-specific DNS Suffix  . :

        Description . . . . . . . . . . . : Broadcom NetXtreme Gigabit Ethernet for hp

        Physical Address. . . . . . . . . : 00-0B-CD-B6-B4-A9

        Dhcp Enabled. . . . . . . . . . . : No

        IP Address. . . . . . . . . . . . : 10.1.0.10

        Subnet Mask . . . . . . . . . . . : 255.255.0.0

        Default Gateway . . . . . . . . . : 10.1.0.1

        DNS Servers . . . . . . . . . . . : 194.72.6.57

                                            194.73.82.242

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## dol-sen

In your first post you list your gateway as a nameserver in resolv.conf.   Your windows box lists 2 nameservers use both of those.

Also is your gateway running a dhcp server.  If it is it can pass all the correct nameserver, etc info to all machines not manually addressed.    In my lan I manually addressed each machine exept for my laptop.

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## smart

i'm still in doubt with the netmask. does the gateway really use the same / same broadcast address ?

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## Dazza

In answer to both the replies. I have tried using both the DNS servers in the past - unfortunately the same problem it just got removed as I have been trying to solve this problem. No we don't have dhcp running.

The netmask is as stated, I tried changing as you suggested smart, but it didn't help. Therefore I don't thik that this is at the root of the problem.

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## smart

you've got traceroute installed ?

in case try

traceroute 194.73.82.242

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## Dazza

I seem to have traceroute6? This is giving me 

traceroute: unknown host 194.73.82.242

I tried to do the same to 10.1.0.1 but got a similar reply.

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## NeddySeagoon

Dazza,

Since ping works out of your PC the hardware is OK. You must have a problem with routining.

Post the output of /sbin/route -n

Regards,

NeddySeagoon

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## smart

Quite possibly, Neddy is right and for whatever reason, your default GW is not set. Regarding traceroute you cannot use traceroute6 since it's designed for ipv6. you'd have to emerge traceroute .

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## Dazza

Destination    Gateway   Genmask          Flags    Metric  Ref   Use  Iface

10.1.0.0        0.0.0.0      255.255.0.0       U         0         0      0      eth0

127.0.0.0       1270.0.1   255.0.0.0          UG       0         0       0     lo

0.0.0.0           10.1.0.1    0.0.0.0             UG       1         0      0      eth0

Here's the table as requested for route -n

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## Dazza

sorry about the bad format above.

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## smart

too bad, except for a missing period in the 2nd line this looks allright.

is your gateway/firewall possibly a closed one and those windows boxes do and your gentoo machine used to use a proxy ?

EDIT: ah no, probably forget that one. your windows box seems to use external DNS directly. let's me think of the possibility that your gateway doesn't provide DNS. in that case, remove it's entry from resolv.conf for it will take seome time until it times out.

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## Dazza

No a proxy was never used and the windows machines don't use one.

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## smart

can you successfully ping any of the two numerical DNS's IP addresses ?

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## Dazza

I can ping the gateway and thats it. That does lead you to think that there is a problem there. But why all of a sudden for this machine and none of the others on the network.

BTW I appreciate your interest and help.

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## smart

is there some kind of logging in the router that you could evaluate ? the only place i can think of right now in charge would be the router, by either not allowing your box to go, or not masquerading it so that the receeiving server would receive your internal IP as sender. don't ask me why that could be just for this box. don't know. in any case, currently i see the router as the only possible source of problem.

for an unlikely 2nd track... did you compile your kernel with firewall support ?

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## NeddySeagoon

Dazza,

Can you ping 216.239.57.99?

Can you ping google.com?

They are both the same place. If ping works by IP and not by name, its a nameserver issue. If its doesn't work at all its a routing issue or hardware issue.

Hardware is ruled out, since you can ping your local LAN.

The routing table you posted looks OK, so if it is routing, then its something in the gateway.

Regards,

NeddySeagoon

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## Dazza

For anyone thats interested. I changed to a different network and used dhcp and everything worked. So basically the firewall had been modified to block me. Now that wasn't very nice was it  :Confused: 

Cheers for the help

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