Hello,
I might be the first to encounter this issue, so I think it is worth posting...
I am trying to set up a configuration in which a DomU and Dom0 are on
their own subnet, and DomU accesses the real network through Dom0''s
NAT.
These are the steps that I take (note, these steps worked fine in
"testing" and "stable" branches):
I first set up a bridge with a private IP:
brctl addbr mybr0
ip addr add 192.168.0.1/24 dev mybr0
ip link set mybr0 up
These are my network scripts in the xend config file:
(network-script network-route)
(vif-script vif-bridge)
(vif-bridge mybr0)
I start a DomU with an IP of 192.168.0.101, and I am able to ping Dom0
(192.186.0.1).
I enable IP forwarding, and I set up NAT:
sysctl -w net.ipv4.ip_forward=1 # (if not allready done by xend)
iptables -t nat -A POSTROUTING -j MASQUERADE \
-o eth0 -s 192.168.0.1/24
I am able to ping the outside world by IP, but name resolution, or any
other TCP/IP traffic does not work.
The very strange part is that tcpdump seems to show packets arriving
at their destination on the outside world hosts. but besides the ACKs,
the outside hosts do not respond.
I am not a networking expert, so I am sorry if my diagnoses is not full.
Here is a bit more info (on Dom0):
# iptables -t nat -L
Chain PREROUTING (policy ACCEPT)
target prot opt source destination
Chain POSTROUTING (policy ACCEPT)
target prot opt source destination
MASQUERADE all -- 192.168.0.0/24 anywhere
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0F:1F:8C:17:D6
inet addr: 10.0.20.10 Bcast:10.0.255.255 Mask:255.255.0.0
UP BROADCAST NOTRAILERS RUNNING MULTICAST MTU:1500 Metric:1
RX packets:30868 errors:0 dropped:0 overruns:0 frame:0
TX packets:1121 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:8172500 (7.7 Mb) TX bytes:158965 (155.2 Kb)
Base address:0xdf40 Memory:fcfe0000-fd000000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:5 errors:0 dropped:0 overruns:0 frame:0
TX packets:5 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:288 (288.0 b) TX bytes:288 (288.0 b)
mybr0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF
inet addr:192.168.0.1 Bcast:0.0.0.0 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:12 errors:0 dropped:0 overruns:0 frame:0
TX packets:13 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:834 (834.0 b) TX bytes:938 (938.0 b)
vif1.0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:13 errors:0 dropped:0 overruns:0 frame:0
TX packets:10 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1044 (1.0 Kb) TX bytes:812 (812.0 b)
# brctl show
bridge name bridge id STP enabled interfaces
mybr0 8000.feffffffffff no vif1.0
Thanks!
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Am Montag, den 20.06.2005, 11:40 -0700 schrieb Eitan Isaacson:> Hello, > I might be the first to encounter this issue, so I think it is worth posting... > > I am trying to set up a configuration in which a DomU and Dom0 are on > their own subnet, and DomU accesses the real network through Dom0''s > NAT. > > These are the steps that I take (note, these steps worked fine in > "testing" and "stable" branches): > > I first set up a bridge with a private IP: > > brctl addbr mybr0 > ip addr add 192.168.0.1/24 dev mybr0 > ip link set mybr0 up > > These are my network scripts in the xend config file: > > (network-script network-route) > (vif-script vif-bridge) > (vif-bridge mybr0) > > I start a DomU with an IP of 192.168.0.101, and I am able to ping Dom0 > (192.186.0.1). > > I enable IP forwarding, and I set up NAT: > > sysctl -w net.ipv4.ip_forward=1 # (if not allready done by xend) > iptables -t nat -A POSTROUTING -j MASQUERADE \ > -o eth0 -s 192.168.0.1/24 > > I am able to ping the outside world by IP, but name resolution, or any > other TCP/IP traffic does not work. > The very strange part is that tcpdump seems to show packets arriving > at their destination on the outside world hosts. but besides the ACKs, > the outside hosts do not respond. > I am not a networking expert, so I am sorry if my diagnoses is not full.I cannot see any error (which does not mean that there is no one). Make sure ("iptables -nL") that the filter chains have all "ACCEPT". So TCP-SYN hits the target, it answers with TCP-SYN/ACK and the last step in the TCP handshake (TCP-ACK domU-->target) is missing, right? Sniff on vif1.0 (or better on domU''s eth0) if the targets answer (TCP-SYN/ACK) arrives at the domU and if the third packet (TCP-ACK) leaves it. Check ("tcpdump -e") if the frames have the correct destination MACs. /nils.> Here is a bit more info (on Dom0): > # iptables -t nat -L > Chain PREROUTING (policy ACCEPT) > target prot opt source destination > > Chain POSTROUTING (policy ACCEPT) > target prot opt source destination > MASQUERADE all -- 192.168.0.0/24 anywhere > > Chain OUTPUT (policy ACCEPT) > target prot opt source destination > > # ifconfig > eth0 Link encap:Ethernet HWaddr 00:0F:1F:8C:17:D6 > inet addr: 10.0.20.10 Bcast:10.0.255.255 Mask:255.255.0.0 > UP BROADCAST NOTRAILERS RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:30868 errors:0 dropped:0 overruns:0 frame:0 > TX packets:1121 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:8172500 (7.7 Mb) TX bytes:158965 (155.2 Kb) > Base address:0xdf40 Memory:fcfe0000-fd000000 > > lo Link encap:Local Loopback > inet addr:127.0.0.1 Mask:255.0.0.0 > UP LOOPBACK RUNNING MTU:16436 Metric:1 > RX packets:5 errors:0 dropped:0 overruns:0 frame:0 > TX packets:5 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:0 > RX bytes:288 (288.0 b) TX bytes:288 (288.0 b) > > mybr0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF > inet addr:192.168.0.1 Bcast:0.0.0.0 Mask:255.255.255.0 > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:12 errors:0 dropped:0 overruns:0 frame:0 > TX packets:13 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:0 > RX bytes:834 (834.0 b) TX bytes:938 (938.0 b) > > vif1.0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:13 errors:0 dropped:0 overruns:0 frame:0 > TX packets:10 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:0 > RX bytes:1044 (1.0 Kb) TX bytes:812 (812.0 b) > > # brctl show > bridge name bridge id STP enabled interfaces > mybr0 8000.feffffffffff no vif1.0-- there is no sig _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
There are some scripts for setting up the NAT already in Xen (although they do not do exactly the same thing as you want to, as no bridge is set up. At least in the original version that I came up with). It would be interesting to see if they work. Cheers Gregor> Hello, > I might be the first to encounter this issue, so I think it is worth > posting... > > I am trying to set up a configuration in which a DomU and Dom0 are on > their own subnet, and DomU accesses the real network through Dom0''s > NAT. > > These are the steps that I take (note, these steps worked fine in > "testing" and "stable" branches): > > I first set up a bridge with a private IP: > > brctl addbr mybr0 > ip addr add 192.168.0.1/24 dev mybr0 > ip link set mybr0 up > > These are my network scripts in the xend config file: > > (network-script network-route) > (vif-script vif-bridge) > (vif-bridge mybr0) > > I start a DomU with an IP of 192.168.0.101, and I am able to ping Dom0 > (192.186.0.1). > > I enable IP forwarding, and I set up NAT: > > sysctl -w net.ipv4.ip_forward=1 # (if not allready done by xend) > iptables -t nat -A POSTROUTING -j MASQUERADE \ > -o eth0 -s 192.168.0.1/24 > > I am able to ping the outside world by IP, but name resolution, or any > other TCP/IP traffic does not work. > The very strange part is that tcpdump seems to show packets arriving > at their destination on the outside world hosts. but besides the ACKs, > the outside hosts do not respond. > I am not a networking expert, so I am sorry if my diagnoses is not full. > > Here is a bit more info (on Dom0): > # iptables -t nat -L > Chain PREROUTING (policy ACCEPT) > target prot opt source destination > > Chain POSTROUTING (policy ACCEPT) > target prot opt source destination > MASQUERADE all -- 192.168.0.0/24 anywhere > > Chain OUTPUT (policy ACCEPT) > target prot opt source destination > > # ifconfig > eth0 Link encap:Ethernet HWaddr 00:0F:1F:8C:17:D6 > inet addr: 10.0.20.10 Bcast:10.0.255.255 Mask:255.255.0.0 > UP BROADCAST NOTRAILERS RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:30868 errors:0 dropped:0 overruns:0 frame:0 > TX packets:1121 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:8172500 (7.7 Mb) TX bytes:158965 (155.2 Kb) > Base address:0xdf40 Memory:fcfe0000-fd000000 > > lo Link encap:Local Loopback > inet addr:127.0.0.1 Mask:255.0.0.0 > UP LOOPBACK RUNNING MTU:16436 Metric:1 > RX packets:5 errors:0 dropped:0 overruns:0 frame:0 > TX packets:5 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:0 > RX bytes:288 (288.0 b) TX bytes:288 (288.0 b) > > mybr0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF > inet addr:192.168.0.1 Bcast:0.0.0.0 Mask:255.255.255.0 > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:12 errors:0 dropped:0 overruns:0 frame:0 > TX packets:13 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:0 > RX bytes:834 (834.0 b) TX bytes:938 (938.0 b) > > vif1.0 Link encap:Ethernet HWaddr FE:FF:FF:FF:FF:FF > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:13 errors:0 dropped:0 overruns:0 frame:0 > TX packets:10 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:0 > RX bytes:1044 (1.0 Kb) TX bytes:812 (812.0 b) > > # brctl show > bridge name bridge id STP enabled interfaces > mybr0 8000.feffffffffff no vif1.0 > > > Thanks! > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel-- Quidquid latine dictum sit, altum viditur --- Anon _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Bernhard Schmidt
2005-Jun-21 17:51 UTC
[Xen-devel] Re: NAT through Dom0 on unstable branch
On 2005-06-20, Eitan Isaacson <ee.jay.eye@gmail.com> wrote: Hi,> I am trying to set up a configuration in which a DomU and Dom0 are on > their own subnet, and DomU accesses the real network through Dom0''s > NAT. > > These are the steps that I take (note, these steps worked fine in > "testing" and "stable" branches):I''ve seen a similar problem, which might or might not be related... Although not being a developer, I''m running XEN unstable because I need ACPI for my network interface chip. My network setup looked like the following ,----------------------------------------------------, | ,-------- | | xen0 ,--------, ,------, | | | | ,-+ vlan10 +--+ br10 +-vif0.0 --- eth0 | | | ,------, | `--------´ `------´ | | | ,--------, | | | | ,--------, ,------, | | | | Switch +--------+ eth0 +--+-+ vlan11 +--+ br11 | | xenU | | `--------´ | | | | `--------´ `------´ | | | | `------, | ,--------, ,------, | | | | `-+ vlan20 +--+ br20 | `-------´ | | `--------´ `------` | | | `----------------------------------------------------´ vlan10 is my internal network connecting all clients, vlan11 was unused, vlan20 contains the PPPoE modem to connect to my ISP. Besides having this PPPoE connection xen0 also runs an IPv6-in-IPv4 tunnel for IPv6 connectivity of the whole network. xen0 only had an RFC1918 IP address and an IPv6 address assigned on br10, a public IPv4 address on ppp0 and another IPv6 address on sixxs (the IPv6-tunnel). xen0 has NAT compiled in and enabled with iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE Connectivity between other clients, xen0 and xenU worked flawless in both IPv4 and IPv6. Other clients could also access the internet being NATed in xen0 for IPv4 and routed in IPv6. xen0 had no connection problems as well. xenU could connect to IPv6 hosts in the internet without a single flaw. But, as soon as a single IPv4 packet was sent from xenU to the internet I could not transfer one single byte through the DSL line anymore, even from xen0 itself. tcpdump on ppp0 showed only incoming packets from some idiots hammering my dynamic IP for peer2peer applications, but not a single byte going out. Routing-table looked good. As soon as I killed pppd (closing ppp0) and restarting it again it worked, until sending IPv4 from xenU again. The box is an Athlon64 in i386-mode on an nVidia nForce3 chipset, the NIC is a Marvell GigE. Both xen0 and xenU are Ubuntu hoary, the xen release was downloaded the day after the patch from 2.6.11.11 to 2.6.11.12 was included in xen-unstable. xen''s own networking scripts creating the bridge at startup have been disabled in favour of manually setting up the vlans and the bridges in the Debian/Ubuntu way. When bridging vlan20 to xenU as well and running PPPoE (and of course masquerading) there everything works like a charm (this is my current setup). Any ideas? Bernhard _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Eitan Isaacson <ee.jay.eye@gmail.com> wrote:> These are the steps that I take (note, these steps worked fine in > "testing" and "stable" branches): > > I first set up a bridge with a private IP: > > brctl addbr mybr0 > ip addr add 192.168.0.1/24 dev mybr0 > ip link set mybr0 up > > These are my network scripts in the xend config file: > > (network-script network-route) > (vif-script vif-bridge) > (vif-bridge mybr0) > > I start a DomU with an IP of 192.168.0.101, and I am able to ping Dom0 > (192.186.0.1). > > I enable IP forwarding, and I set up NAT: > > sysctl -w net.ipv4.ip_forward=1 # (if not allready done by xend) > iptables -t nat -A POSTROUTING -j MASQUERADE \ > -o eth0 -s 192.168.0.1/24An alternative solution would be: iptables -t nat -F POSTROUTING iptables -t nat -F PREROUTING iptables -t nat -A POSTROUTING -o eth0 -s 192.168.2.0/24 -j SNAT \ --to-source <your.public.ip.address> for incoming connections you could do some portforwarding: iptables -t nat -A PREROUTING -i eth0 -d <your.public.ip.address> \ -p tcp --dport 80 -j DNAT --to-dest <ip.address.of.domU> by Töns -- There is no safe distance. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
On Tue, 2005-06-21 at 21:15 +0200, Toens Bueker wrote:> Eitan Isaacson <ee.jay.eye@gmail.com> wrote: > > sysctl -w net.ipv4.ip_forward=1 # (if not allready done by xend) > > iptables -t nat -A POSTROUTING -j MASQUERADE \ > > -o eth0 -s 192.168.0.1/24 > > An alternative solution would be: > > iptables -t nat -F POSTROUTING > iptables -t nat -F PREROUTING > iptables -t nat -A POSTROUTING -o eth0 -s 192.168.2.0/24 -j SNAT \ > --to-source <your.public.ip.address>Yes. Unless the IP address of eth0 is dynamic, the latter form is preferable. Cheers, Rusty. -- A bad analogy is like a leaky screwdriver -- Richard Braakman _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
I''ve met a similar case with my desktop and laptop computer connected with a switcher, not in XEN. The reason of my problem is that I set a conflict IP address in one of my computer with the maintenance IP address of DSL modem. And when the conflicting computer send out packets, the switcher puzzled and frozen. (Many DSL modems use IP address like 192.168.0.1, 192.168.0.11, 10.0.0.1 and so on) It may not be the reason of your case. Just for you information. Bernhard Schmidt <berni@birkenwald.de> Sent by: xen-devel-bounces@lists.xensource.com 2005-06-22 01:51 To xen-devel@lists.xensource.com cc Subject [Xen-devel] Re: NAT through Dom0 on unstable branch On 2005-06-20, Eitan Isaacson <ee.jay.eye@gmail.com> wrote: Hi,> I am trying to set up a configuration in which a DomU and Dom0 are on > their own subnet, and DomU accesses the real network through Dom0''s > NAT. > > These are the steps that I take (note, these steps worked fine in > "testing" and "stable" branches):I''ve seen a similar problem, which might or might not be related... Although not being a developer, I''m running XEN unstable because I need ACPI for my network interface chip. My network setup looked like the following ,----------------------------------------------------, | ,-------- | | xen0 ,--------, ,------, | | | | ,-+ vlan10 +--+ br10 +-vif0.0 --- eth0 | | | ,------, | `--------´ `------´ | | | ,--------, | | | | ,--------, ,------, | | | | Switch +--------+ eth0 +--+-+ vlan11 +--+ br11 | | xenU | | `--------´ | | | | `--------´ `------´ | | | | `------, | ,--------, ,------, | | | | `-+ vlan20 +--+ br20 | `-------´ | | `--------´ `------` | | | `----------------------------------------------------´ vlan10 is my internal network connecting all clients, vlan11 was unused, vlan20 contains the PPPoE modem to connect to my ISP. Besides having this PPPoE connection xen0 also runs an IPv6-in-IPv4 tunnel for IPv6 connectivity of the whole network. xen0 only had an RFC1918 IP address and an IPv6 address assigned on br10, a public IPv4 address on ppp0 and another IPv6 address on sixxs (the IPv6-tunnel). xen0 has NAT compiled in and enabled with iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE Connectivity between other clients, xen0 and xenU worked flawless in both IPv4 and IPv6. Other clients could also access the internet being NATed in xen0 for IPv4 and routed in IPv6. xen0 had no connection problems as well. xenU could connect to IPv6 hosts in the internet without a single flaw. But, as soon as a single IPv4 packet was sent from xenU to the internet I could not transfer one single byte through the DSL line anymore, even from xen0 itself. tcpdump on ppp0 showed only incoming packets from some idiots hammering my dynamic IP for peer2peer applications, but not a single byte going out. Routing-table looked good. As soon as I killed pppd (closing ppp0) and restarting it again it worked, until sending IPv4 from xenU again. The box is an Athlon64 in i386-mode on an nVidia nForce3 chipset, the NIC is a Marvell GigE. Both xen0 and xenU are Ubuntu hoary, the xen release was downloaded the day after the patch from 2.6.11.11 to 2.6.11.12 was included in xen-unstable. xen''s own networking scripts creating the bridge at startup have been disabled in favour of manually setting up the vlans and the bridges in the Debian/Ubuntu way. When bridging vlan20 to xenU as well and running PPPoE (and of course masquerading) there everything works like a charm (this is my current setup). Any ideas? Bernhard _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel