Re: [Vserver] Network problem

From: Herbert Poetzl <herbert_at_13thfloor.at>
Date: Mon 19 Dec 2005 - 19:35:40 GMT
Message-ID: <20051219193540.GD8047@MAIL.13thfloor.at>

On Mon, Dec 19, 2005 at 02:19:50PM -0500, Jairo Enrique Serrano Castaņeda wrote:
> 2005/12/19, Herbert Poetzl <herbert@13thfloor.at>:
> >
> > On Mon, Dec 19, 2005 at 01:00:48PM -0500, Jairo Enrique Serrano Castaņeda
> > wrote:
> > > >
> > > >
> > > > not unexpected, unless your router (172.16.3.16)
> > > > also masquerades private addresses like 192.168.1.2
> > >
> > >
> > > my unusual router are 172.16.3.16
> > >
> > > > how do it?
> > > >
> > > > simple:
> > > >
> > > iptables -t nat -I POSTROUTING -s 192.168.1.2 -j SNAT --to 172.16.3.102
> > >
> > >
> > > i have a "real" network ip of my lan... 172.16.3.103, i do a ip alias
> > >
> > > # Original
> > > iface eth0 inet static
> > > address 172.16.3.102
> > > netmask 255.255.255.0
> > > network 172.16.3.0
> > > broadcast 172.16.3.255
> > > gateway 172.16.3.16
> > > # dns-* options are implemented by the resolvconf package, if
> > > installed
> > > dns-nameservers 200.106.128.4
> > >
> > > #alias
> > > iface eth0:1 inet static
> > > address 172.16.3.103
> > > netmask 255.255.255.0
> > > network 172.16.3.0
> > > broadcast 172.16.3.255
> > > gateway 172.16.3.16
> >
> > the second gateway is confusing ... at least it might
> > give strange results for 'different' gateways/networks
> >
> > dns-nameservers 200.106.128.4
> > >
> > >
> > > in the virtual server have:
> > > root@sv1:/# route
> > > Kernel IP routing table
> > > Destination Gateway Genmask Flags Metric Ref Use
> > > Iface
> > > 172.16.3.0 * 255.255.255.0 U 0 0 0
> > eth0
> > > default 172.16.3.16 0.0.0.0 UG 0 0 0
> > eth0
> > > default 172.16.3.16 0.0.0.0 UG 0 0 0
> > eth0
> > >
> > > in the Host server have:
> > > savio@sv0:~$ route
> > > Kernel IP routing table
> > > Destination Gateway Genmask Flags Metric Ref Use
> > > Iface
> > > localnet * 255.255.255.0 U 0 0 0
> > eth0
> > > default 172.16.3.16 0.0.0.0 UG 0 0 0
> > eth0
> > > default 172.16.3.16 0.0.0.0 UG 0 0 0
> > eth0
> > >
> > > looks equal...
> >
> > yep, should be fine too, your last email contained
> > a guest setup with 192.168.x.x though ...
>
>
> sorry for the change... in not know to do... ;)
>
> > the two ips are functional...
> > >
> > ------------------------------------------------------------------------------------------------
> > >
> > > savio@sv0:~$ ping 172.16.3.102
> > > PING 172.16.3.102 (172.16.3.102) 56(84) bytes of data.
> > > 64 bytes from 172.16.3.102: icmp_seq=1 ttl=64 time=0.023 ms
> > > 64 bytes from 172.16.3.102: icmp_seq=2 ttl=64 time=0.007 ms
> > > --- 172.16.3.102 ping statistics ---
> >
> > as you see, this doesn't tell anything, it just
> > contacts localhost, and the packet is transmitted
> > via the loopback device (does not even hit the
> > network or router)
> >
> > > 2 packets transmitted, 2 received, 0% packet loss, time 999ms
> > > rtt min/avg/max/mdev = 0.007/0.015/0.023/0.008 ms
> > >
> > >
> > ------------------------------------------------------------------------------------------------
> > >
> > > savio@sv0:~$ ping 172.16.3.103
> > > PING 172.16.3.103 (172.16.3.103) 56(84) bytes of data.
> > > 64 bytes from 172.16.3.103: icmp_seq=1 ttl=64 time=0.018 ms
> > > 64 bytes from 172.16.3.103: icmp_seq=2 ttl=64 time=0.008 ms
> > > --- 172.16.3.103 ping statistics ---
> > > 2 packets transmitted, 2 received, 0% packet loss, time 1000ms
> > > rtt min/avg/max/mdev = 0.008/0.013/0.018/0.005 ms
> > >
> > >
> > ------------------------------------------------------------------------------------------------
> >
> > try the following (on the host) just to verify that
> > your router is doing the proper stuff:
> >
> > ping -c 2 -I 172.16.3.102 www.google.com
>
> ----------------------------------------------------------------------------------------------------------------------
> in the server..
> root@sv0:/home/savio# ping -c 2 -I 172.16.3.102 www.google.com
> PING www.l.google.com (64.233.187.104) from 172.16.3.102 : 56(84) bytes of
> data.
> 64 bytes from 64.233.187.104: icmp_seq=1 ttl=242 time=159 ms
> 64 bytes from 64.233.187.104: icmp_seq=2 ttl=242 time=213 ms
>
> --- www.l.google.com ping statistics ---
> 2 packets transmitted, 2 received, 0% packet loss, time 1002ms
> rtt min/avg/max/mdev = 159.191/186.328/213.466/27.140 ms
> ----------------------------------------------------------------------------------------------------------------------
> in the vserver...
> root@sv0:/home/savio# vserver sv1 enter
> mesg: /dev/pts/0: Operation not permitted
> root@sv1:/# ping -c 2 -I 172.16.3.102 www.google.com
> ping: unknown host www.google.com
>

the second ping is also supposed to be done
_on the host_ and not inside the guest

> :( dont works...
> ----------------------------------------------------------------------------------------------------------------------
>
> ping -c 2 -I 172.16.3.103 www.google.com
> >
> > if one of those fails (or both) then something is
> > broken with your router

if it failed on the host, then this means that
172.16.3.103 is not properly routed ...
you could try the following as a workaround:

 iptables -t nat -I POSTROUTING -s 172.16.3.103 -j SNAT --to 172.16.3.102

which remaps it to the 'working' ip ...
retry the ping on the host, and check inside
the guest ...

HTH,
Herbert

> i try to see in the router (not work with that - the firewall administrator
> its other people...)
>
> > but not resolv functional...
> >
> > verify that /etc/resolv.conf has proper nameserver
> > entries inside the guest (i.e. very likely the same
> > ones you have on the host)
>
>
> server:
> root@sv0:/home/savio# cat /etc/resolv.conf
> nameserver 200.106.128.4
> vserver:
> root@sv1:/# cat /etc/resolv.conf
> nameserver 200.106.128.4
>
> HTH,
> > Herbert
> >
> > > > any fault in the config???
> > > >
> > > > no, looks fine, although I'd add a prefix (e.g.
> > > > containing 24) to the interfaces/0
> > > >
> > > > HTH,
> > > > Herbert
> >
>
>
> Thanks a lot for your help!
>
> --
> Jairo Enrique Serrano Castaņeda
> Ingeniero de Sistemas UTB
> http://www.jsnat.com
> http://www.drupal.org.es

> _______________________________________________
> Vserver mailing list
> Vserver@list.linux-vserver.org
> http://list.linux-vserver.org/mailman/listinfo/vserver

_______________________________________________
Vserver mailing list
Vserver@list.linux-vserver.org
http://list.linux-vserver.org/mailman/listinfo/vserver
Received on Mon Dec 19 19:36:05 2005

[Next/Previous Months] [Main vserver Project Homepage] [Howto Subscribe/Unsubscribe] [Paul Sladen's vserver stuff]
Generated on Mon 19 Dec 2005 - 19:36:10 GMT by hypermail 2.1.8