Re: [coLinux-users] unable to get slirp (ping) working

[Henry N. <hen...@ar...>]

  Hari Krishna Dara wrote:
> On Sat, May 8, 2010 at 3:39 PM, Henry Nestler wrote:
>>   Hari Krishna Dara wrote:
>>> eth0=slirp
>>>
>>> On the linux side, I used dhcp and after a reboot, I do get the right
>>> values for ip (10.0.2.15) and gateway (10.0.2.2). I can ping to
>>> 10.0.2.2 and 10.0.2.3 as well, but I can't ping to anything outside,
>>> even though their ip gets resolved.
>> Ping (IMCP-protocol) is not supported by SLiRP.
>> Try any other applications with TCP or UDP to check the connection, for
>> example "wget google.com"
>>
> I can't believe I missed to see this information already documented,
> thanks for pointing it out. I can see that I am able to access both
> internet and VPN via slirp.  However, there are a few issues:
> - Name resolution is not working well. I can't resolve names over VPN
> (even after adding my VPN name servers to /etc/resolve.conf file) and
> a few others that can be resolved from WXP (e.g., names in my local
> network).

SLiRP use only the first nameserver from Windows and forwards it under 
10.0.2.3. So, it is a good idea, to add more nameserver's in 
/etc/resolve.conf manualy. For me, it works in special environment with 
DNS server on intranet (closed DNS, not Internet) it was ok. Not 
explicitly tested for a VPN.

> - I have my tuntap adapter getting registered as the default gateway,
> so at first nothing worked. Only when I added the slirp gateway as the
> default gateway and removed the tuntap gateway from being the default,
> the internet even started worked. Is there a better solution for this
> than putting the route commands in /etc/rc.d/rc.local file?

Don't set any gateway for TAP.

TAP is a private network between Linux and host and not need a default 
gateway. The route for this network will automatically set after the 
interface will coming up.

That means, don't set gateway in file /etc/network/interfaces for tap 
device under Debian.

PS: In some docs a gateway was set, because TAP device was used as 
"Internet connect sharing" (ICS).

> On a side note, I also notice that tuntap adapter started becoming my
> default gateway on XP side as well, not sure what is causing this. May
> be a reboot will fix it.

I hope the TAP has an other network range as all your other networks 
(Ethernet cards and Wi-Fi). And the same as under Linux: Don't set a 
route or gateway for TAP device.

-- 
Henry N.