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CentOS Guest not attaching to VPN

Posted: 6. Mar 2015, 16:36
by StevenWright
Hi,
I am having a problem getting my CentOS 6 guest to attach to the Windows 8.1 host's VPN connection.

VirtualBox: 4.3.24
Windows: 8.1
Guest Additions are installed: 4.3.24

I run the host on two different networks, my office, and my home. Everything works as expected when at the office.

When I am at home I do the following:
1. start the host
2. start the Fortinet VPN client and establish a connection.
3. start the CentOS guest

In the host network config I can see that my wired adapter has an IP from my home router, something like 192.168.1.77. I also see the PPP adapter that Fortinet creates for the VPN. In addition I see the 192.168.56.1 adapter that the Host-Only network creates.

I have tried the guest running in both NAT and Bridged. I believe that NAT mode is the correct mode, but I tried bridged out of desperation. In bridged mode the guest has an address of something like 192.168.1.88 and in NAT mode it gets something like 10.0.2.15.

I think the problem might be that the Fortinet VPN uses PPP. The VB documentation states "Protocols other than TCP and UDP are not supported". I am not that good with networking but I thought PPP was part of TCP.

In any case this is the problem. On the host I can hit the URLs:
svn://sourcecontrol.etisoftware.local which is the same as svn://10.1.2.71

In the guest I get a host unknown or unreachable.

So how do I get the guest to use the host's VPN? Does the Fortinet VPN make this impossible?

Re: CentOS Guest not attaching to VPN

Posted: 6. Mar 2015, 17:20
by StevenWright
Interesting, I have more network weirdness that may or may not be related. I am in the office and the guest is running in NAT mode. My guest interface config is:

Code: Select all

[swright@dev01 ~]$ ifconfig
eth0      Link encap:Ethernet  HWaddr 08:00:27:7F:26:2F  
          inet addr:10.0.2.15  Bcast:10.0.2.255  Mask:255.255.255.0
          inet6 addr: fe80::a00:27ff:fe7f:262f/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:19 errors:0 dropped:0 overruns:0 frame:0
          TX packets:150 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:3310 (3.2 KiB)  TX bytes:13704 (13.3 KiB)
And I cannot ping www.google.com.

Code: Select all

[swright@dev01 ~]$ ping www.google.com
ping: unknown host www.google.com

Re: CentOS Guest not attaching to VPN

Posted: 6. Mar 2015, 17:54
by StevenWright
Maybe this is a problem with NAT. Because I can get to addresses inside my office network, but nothing outside of it.

Code: Select all

[swright@dev01 ~]$ ping www.google.com
ping: unknown host www.google.com
[swright@dev01 ~]$ ping 10.1.2.71
PING 10.1.2.71 (10.1.2.71) 56(84) bytes of data.
64 bytes from 10.1.2.71: icmp_seq=1 ttl=64 time=1.39 ms
64 bytes from 10.1.2.71: icmp_seq=2 ttl=64 time=1.01 ms
64 bytes from 10.1.2.71: icmp_seq=3 ttl=64 time=0.837 ms
64 bytes from 10.1.2.71: icmp_seq=4 ttl=64 time=1.75 ms
64 bytes from 10.1.2.71: icmp_seq=5 ttl=64 time=1.62 ms
^C
--- 10.1.2.71 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4859ms
rtt min/avg/max/mdev = 0.837/1.326/1.757/0.352 ms

If I change to Bridged mode I get this:

Code: Select all

[swright@dev01 ~]$ ifconfig
eth0      Link encap:Ethernet  HWaddr 08:00:27:7F:26:2F  
          inet addr:10.1.1.123  Bcast:10.1.3.255  Mask:255.255.252.0
          inet6 addr: fe80::a00:27ff:fe7f:262f/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:125 errors:0 dropped:0 overruns:0 frame:0
          TX packets:386 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:21904 (21.3 KiB)  TX bytes:34008 (33.2 KiB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:40 errors:0 dropped:0 overruns:0 frame:0
          TX packets:40 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:3240 (3.1 KiB)  TX bytes:3240 (3.1 KiB)

[swright@dev01 ~]$ 
[swright@dev01 ~]$ 
[swright@dev01 ~]$ ping www.google.com
PING www.google.com (74.125.137.147) 56(84) bytes of data.
64 bytes from yh-in-f147.1e100.net (74.125.137.147): icmp_seq=1 ttl=48 time=4.41 ms
64 bytes from yh-in-f147.1e100.net (74.125.137.147): icmp_seq=2 ttl=48 time=4.23 ms
^C
--- www.google.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1917ms
rtt min/avg/max/mdev = 4.235/4.325/4.415/0.090 ms

Re: CentOS Guest not attaching to VPN

Posted: 6. Mar 2015, 18:00
by StevenWright
I setup a Windows 7 Guest. The NAT problem shows up there too. Bridged Mode works fine.

Re: CentOS Guest not attaching to VPN

Posted: 6. Mar 2015, 20:08
by StevenWright
Further troubleshooting. I installed VMWare. I setup a CentOS 6 VM using NAT. It works as expected.

Code: Select all

[swright@localhost ~]$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:0C:29:4E:DF:EF  
          inet addr:192.168.2.128  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe4e:dfef/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:33 errors:0 dropped:0 overruns:0 frame:0
          TX packets:46 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:12116 (11.8 KiB)  TX bytes:4381 (4.2 KiB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:8 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:480 (480.0 b)  TX bytes:480 (480.0 b)

[swright@localhost ~]$ ping www.google.com
PING www.google.com (173.194.46.48) 56(84) bytes of data.
64 bytes from ord08s10-in-f16.1e100.net (173.194.46.48): icmp_seq=1 ttl=128 time=24.7 ms
64 bytes from ord08s10-in-f16.1e100.net (173.194.46.48): icmp_seq=2 ttl=128 time=25.2 ms
64 bytes from ord08s10-in-f16.1e100.net (173.194.46.48): icmp_seq=3 ttl=128 time=24.9 ms
64 bytes from ord08s10-in-f16.1e100.net (173.194.46.48): icmp_seq=4 ttl=128 time=25.4 ms
64 bytes from ord08s10-in-f16.1e100.net (173.194.46.48): icmp_seq=5 ttl=128 time=24.9 ms
^C
--- www.google.com ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4417ms
rtt min/avg/max/mdev = 24.774/25.050/25.422/0.310 ms
[swright@localhost ~]$