Yep, agreed - and have DNS (on the subnet) up and running. Need to follow the 
instructions in the other email, see if I can get that up and running over TUN.

FYI, I can't send ICMP outside the tunnel - it gets blocked (doesn't get out) 
... ☹.

Thanks!

... Russell




-----Original Message-----
From: Jan Just Keijser [mailto:[email protected]] 
Sent: Friday, July 7, 2017 9:38 AM
To: [email protected]; Morris, Russell <[email protected]>
Subject: Re: [Openvpn-users] Intermittent Connectivity

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.

JJK


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