Bridged networking with Virtual machines problem

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Djago
Posts: 23
Joined: Sat Nov 28, 2015 6:08 pm

Re: Bridged networking with Virtual machines problem

Post by Djago »

I've changed the driver of my NIC (it was using the standard MS driver that came with Windows, and I fall back to an old TP-Link driver for Windows 8, and I had to force the isntallation because Windows didn't want it).
Also I've started the config of the router from scratch.

Now Bridged mode is working.

I don't know if the problem was the driver or something in my old configuration. Sorry, I should have done this in two steps...

sedilson
Posts: 7
Joined: Fri Jan 19, 2018 12:19 pm

Re: Bridged networking with Virtual machines problem

Post by sedilson »

Hey guys,
Just sign up to post a report of the same problem and saw this.
Allow me to resurrect the topic with my scenario:

Win7 Guest Runnig on Win7 Host, bridged using WiFi built in Intel adapter.

TP1043 (Gargoyle 1.10) connected to ISP modem set as router, so I have tow routers. 1043 has static IP settings and its IP is on DMZ of the ISP router.

Important:
The bridge worked for months, but last week it failed to get IP from DHCP (1st symptom). Doing address reservation and rebooting the router, Win7 guest could get IP from 1043 but no connection to internet (2nd symptom)

- Ping from Win7 Guest to GW (1043): Reply
- Ping from Win7 Guest to google: No reply
- Ping from Win7 Guest to 1043 wan interface: Reply
- Ping from Win7 Guest to ISP modem GW: No reply

Doing the same from Win7 host, all reply.

Digging a little bit, I took a switch and configured a mirror session to sniff the 1043 wan traffic.
What I see is that, the ping from guest to google, the ICMP messages are not showing at the 1043 output
Doing the same from host, I can see the ICMP packets going out.

In order to exclude possible problem I:
1)
Using the same VM setup, but instead of booting using Windows, I booted to a live session of Ubuntu. Intention here was test is the problem resided on Windows. Ubuntu's live session presented exactly the same problem.
2)
Launching windows XP mode using MS VM. I have also bridged MS VM to WiFi adapter. Intention here was assure if the problem ireleted to the use of VMWare or any VM implementation. XP mode presented the same problem
3)
Not touching the VMWare setup (VMWare installation, Host and Guest), I just replaced 1043 by a Belking router with exactly same setup as possible (network address, subnet, AP settings). Problem disappeared on VMware setup and on XP Mode.

I have been facing that problem for some time. The solution I found was setup the router from scratch and in my case, it works for some time, then suddenly stops.
I have manually set different IP addresses to Guest, within the defined subnet /24, to assure that there was no some sort of persistence. For the same reason, I have also changed the guest MAC addresses.

Conclusion, based on the above testings:

1043 running Gargoyle prevents the packet from guest system to be properly routed as I don't see the Guest ICMP ping messages flowing out from 1043 Wan interface as i see if tried from Host.

Finally, if it change the bridging from WiFi to ETH adapter, it works. but note that, in the past, i had the same problem but on ETH instead of WiFi. It leads me to think that it breaks after some use time.

Not trying to convince anyone Gargoyle is the guilty. My intention is ask if someone can point me on how to trouble-shoot Gargoyle's router to follow the packet over its firewall.
Maybe a iptables logging of something?

sedilson
Posts: 7
Joined: Fri Jan 19, 2018 12:19 pm

Re: Bridged networking with Virtual machines problem

Post by sedilson »

I was trying to understand the issue, so I was following iptables troubleshooting instructions on the following site: "3w microhowto info / troubleshooting / troubleshooting_iptables.html"

I have performed the following commands, as instructed:

Code: Select all

iptables -t nat -L POSTROUTING #(lists NAT POSTROUTING rules)
iptables -t nat -L #(lists NAT rules)
iptables -t nat -Z #(zeros NAT counters)
iptables -t nat -L -v -n #(lists NAT rules with verbose mode and counters)
Then I tested the ping, to start my troubleshooting, and it worked. Of course, none of the above commands intended to fix anything, but just troubleshoot. So, I don't know, somehow WiFi adapter bridge to VM resumed normal operation.

This way, when and if the issue come up again, I'll will perform the same troubleshooting steps to see if they lead to the same result, testing ping after perform each one for tracking.

sedilson
Posts: 7
Joined: Fri Jan 19, 2018 12:19 pm

Re: Bridged networking with Virtual machines problem

Post by sedilson »

Hey Guys.

The problem happened two months ago and running the same commands did not produce the same result.
But I think that i narrow the problem a little bit more.

Today, I had a issue with my actual PC.
I have two NIC on that PC. I have used the second one to test a new router I got. That router was connected to Gargoyle.
Last week I connected that NIC on Gargoyle directly and it worked just fine. However, today it just didn't.
Disable enable interface on windows, reboot the PC didn't have any effect. I could open Gargoyle interface but the traffic was not going further, exactly the same thing with VM.

So, I thought about the MAC been somehow stuck.
Googling for that, I found that OpenWRT had that arp table stuckness issue.

Performing

Code: Select all

arp -a
i could see the ip and mac of that pc. So i disabled the nic on windows and used the following command,

Code: Select all

ip -s -s neigh flush all
,to clear arp table. Checking arp table again, it was unchanged.
I ran the command few timed and nothing. Then i decided to reboot Gargoyle. After reboot was complete, i checked arp table again and only the 4 hosts connected to gargoyle were present on the table.

Then finally, I have enabled the NIC back on windows and everything was back to normal.

I still need to prove that again just to be sure that it was the art flush that resolved the problem or if was the reboot.
But note that, while that PC was having issue to connect, all other hosts connected to Gargoyle were accessing the interned with no problem at all.

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