Can't access the internet from Ubuntu guest

[coldcandor]

Hello all!

I have been bouncing between posts all day and none of them seem to help, so I gave up and registered so I could post specifics. Here's the rundown:

I am running Ubuntu Server 10.04 on the latest version of VirtualBox (4.1.8).
My host system is Windows XP SP3 (32 bit)
I am running a webserver off of this guest
I have a Bridged Adapter set up with these settings:
Name: MAC Bridge Miniport
Adapter Type: Intel PRO/1000 MT Desktop (82540EM)
Allow VMs
I have set up the web domain through godaddy
I can access the website successfully at coldcandor
I have port forwarding set up on my router for H T T P, FTP, SSH, and Telnet

Now here's the problem: I can't access the internet from the guest terminal. I can't ping, I can't run apt-get update, nothing. I also can't ping the webserver from my router using the local LAN IP. Obviously this wasn't always the case, because I was able to set up the web server, firewall, email, etc using apt-get the first time around. Unfortunately that was over a year ago at this point.

This is driving me insane. Please help!

Also, the anti-u r l paserer on this forum desperately needs fixing. I just spent 30 minutes trying to figure out why it was telling me I needed to wait a day and a post to include U R Ls. Stupid thing is detecting u r l and h t t p as actual addresses. I was extremely close to giving up completely and finding a different product.

[Sasquatch]

Sorry about the URL detection, but it's done to avoid more spam.

Please provide the IP address inside the Guest, along with how it's configured (should be in /etc/network/interfaces) and the configuration of the physical network (IP range, router IP, Host IP). Can you ping the Guest from the Host?

[coldcandor]

I do understand the why, but the regex can definitely be improved! Anyway, I won't dwell on that any further.

/etc/network/interfaces

Code: Select all

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
        address 192.168.1.5
        netmask 255.255.255.0
        network 192.168.1.0
        broadcast 192.168.1.255
        gateway 192.168.1.1
        # dns-* options are implemented by the resolvconf package, if installed
        dns-nameservers 192.168.1.1 68.237.161.12
        dns-search home

LAN IP range is the classic 192.168.1.255 mask.

I can NOT ping [public IP] (router) from inside the guest and I can NOT ping 192.168.1.5 (guest) from the router (I CAN ping the two physical PCs at .2 and .7, .7 is the VirtualBox host).

I'm not sure I understand all the pieces you are looking for, so hopefully that covers it!

[Sasquatch]

if the Guest (192.168.1.5) can ping the physical machines (192.168.1.2 and 192.168.1.7), then it should also be able to ping the router at 192.168.1.1. Remember, you might have configured the router to block ping on it's WAN port, so trying to ping it's external IP won't work. I've also modified your post to remove your public IP. Don't want unwanted visitors .

Instead of trying local and close-by devices, try something further. Like a DNS request. There are some network tests in the VirtualBox FAQ. Try them and report back.

[coldcandor]

Thanks for the presence of mind to remove that, wasn't even thinking about spam! I can in fact ping the router via the local .1 address, and pinging something far away (like yahoo) resolves the name fine so far as I can tell
18:16:33 {~} $ ping www.yahoo.com
PING any-fp3-real.wa1.b.yahoo.com (98.139.180.149) 56(84) bytes of data.
So I wouldn't be at all surprised if PINGs are blocked, but it appears DNS is working fine. In fact, I can ping my website and it will resolve to the correct IP, and to my surprise it now actually pings successfully! Things like yahoo still fail to return, however.

Unfortunately I have already found that post and nothing there helped.

So, I guess two things:
1) What exactly is a DNS request? I'll try one of those and see if I get anything different.
2) Should I try going through the whole process of switching from Bridged to NAT and custom setting up DNS? I have tried NAT before and couldn't get it to do anything whatsoever. As it sits now, the website works, along with all it's subdomains, I just can't do things like update installed modules on the guest system.

[Sasquatch]

If DNS resolving works, then it can reach internet. It asks the router to resolve the domain name to an IP address and that works. So next step is to use Google as example, do a DNS request, then a ping to both the domain name and the IP address you get and then dump both in a browser window.

The FAQ also noted traceroute, so you can see how far your traffic goes. E.g. it stops at the router, or it stops somewhere on the web. In the latter case, it's off your hands and internet should work fine.

If all fails, except the DNS resolving, then you have to look at your Host, how it connects to the internet. You may need a proxy.

[coldcandor]

Argh! Traceroute isn't installed...

The program 'traceroute' can be found in the following packages:
* traceroute
* traceroute-nanog
Try: sudo apt-get install <selected package>

Ping http://www.google.com gave me 74.125.113.103, which successfully directs me to google in a browser, so DNS is definitely working. Unfortunately I know nothing about proxy servers. Any thoughts or references you prefer?

[Sasquatch]

Ok, so the DNS resolving works. Then entering the IP address you got in a browser gave you the website. But, if you enter the domain name used for ping, it won't work, right? That really does not make sense.

[coldcandor]

Exactly. Now you understand why this is driving me insane! The simple fact that it can serve webpages to visitors means it can connect to the internet somehow, just not when I tell it to directly...

Your last comment before

If all fails, except the DNS resolving, then you have to look at your Host, how it connects to the internet. You may need a proxy.

Seems to fit, but I don't know what I would be looking for from that end.

[Sasquatch]

Proxies are servers that can speed up your internet experience by caching websites, but it can also be used to police access, like blocking certain sites. In companies, it's usually used to force users to use a proxy before they can use internet. DNS queries can bypass proxies, so they will always work.

But, since you can access websites through their IP address directly, it seems you don't need one. You can check your browser settings on the Host for it.

[coldcandor]

That certainly sounds like adding a proxy would be unlikely to fix anything, while removing or editing one is a common one. I can guarantee I do not currently use one.

You mentioned a couple times checking the host settings. Could you expand on that a little?

Also, thank you for spending so much time helping me through this! I really appreciate it.

[Sasquatch]

You have to compare the network settings of the Guest with the Host. This means the IP address (only the last digit will differ), gateway, DNS server(s), perhaps even browser proxy settings. Oh, and firewall, that too. I'm assuming here that you have the Guest on Bridged.

[isisBlues]

Will there be an impact if the guest is not bridged but is through NAT.
The site that I followed during the installation recommended NAT, but now I seem to be having a variation of this problem.
My guest terminal can't connect to the server, but it's browser is able to connect to the internet.