On 07/07/17 16:38, Jan Just Keijser wrote:
> Hi,
> 
> On 07/07/17 15:00, David Sommerseth wrote:
>> On 06/07/17 19:07, Morris, Russell wrote:
>>> Hi,
>>>
>>> OK, pulling my hair out with this. I haven't really seen this before,
>>> but having issues with intermittent connectivity (lately, also with
>>> the latest versions of OpenVPN). I noticed it over SSH (connection
>>> seems to hang for periods of time), so then I tried ping => results
>>> below, and quite interesting (and very variable).
>>>
>>> In case someone asks - I am running over TCP, but have never seen
>>> this before (so I'm not sure that's really the issue). I did try
>>> connecting to a second machine (different location) ... and that
>>> seems OK (but it's running TUN, vs. TAP - part of the issue?).
>>>
>> [...snip...]
>>> Thoughts? Things to try?
>> This looks like a typical wacky connection between client and server.
>> And using --proto tcp with wacky connections, things tends to get ugly
>> quickly.  And especially when sending TCP packets inside the tunnel.
>> That results in a lot of "resend this packet" requests both on the
>> inside and outside of the tunnel.  So try switching to --proto udp.
> agreed, but do note that Morris is sending ICMP packets inside the
> tunnel - so that rules out some of the TCP-over-TCP badness.
> It would be interesting to see the simultaneous ping results *outside*
> the tunnel, i.e. between client and VPN server.
>>> And yes, I do need TAP, as I need to bridge onto the subnet (to
>>> access different machines remotely).
>> "to access different machines remotely" is very seldom a good argument
>> for bridging.  If your remote machines understands TCP/IP routing
>> properly, you will most likely have a far better result using a routed
>> TUN setup, with the VPN link (tun adapters) residing in their own
>> subnet.  This will remove a lot of broadcast traffic, which can eat up
>> the bandwidth - especially there's lots of broadcast chatter on both
>> sides of the tunnel.  Plus the packets transported between the VPN
>> client and server is also a bit smaller, as it doesn't need the Ethernet
>> frame (which contains MAC addresses among others).
>>
>> Those scenarios where bridging really makes sense are for non-TCP/IP
>> protocols or where the application protocol really depends on broadcast
>> traffic (like older LAN games).  If you think of Windows file shares, it
>> is far better to use WINS, which works very well over routed TUN.
>>
>>
> again, I fully agree with David, *BUT*  Microsoft has declared WINS to
> be dead; it's even so bad that there are DoS holes in the WINS server
> that they will not fix; you should switch to DNS/AD style name serving
> instead.
Thanks! :)  As I'm not an active Windows user, I just re-iterate what
has been said for many years - and I was not aware of the DoS holes ...
no real excuse, but thanks for point that out!  I agree DNS/AD is far
better though.


--
kind regards,

David Sommerseth

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