Looking for a push in the right direction with my VPN.... (fw d)

Biggerstaff, Craig Craig.Biggerstaff at CSOCONLINE.COM
Thu Aug 3 09:53:15 EDT 2000


> From: DePriest, Jason R. [mailto:jrdepriest at ftb.com]
>
> We are using PowerVPN 6.5 running on a Windows NT system.
> The MTU at the
> router is set to allow standard ethernet 1500.  And, of
> course, the client
> operating systems (Windows 9x and Windows NT) automatically
> set the don't
> fragment flag on the ESP traffic.
>
> The problem is this, when using a dial-up connection with a
> default MTU 576,
> I have no problems.  I can use Outlook 2000 to access my
> Exchange email, I
> can NET USE to map to shared resources, I can use IE5.01SP1
> to access the
> Intranet, and I can use the SNA client to access mainframe sessions.
> When trying to through Road Runner with my cable modem,
> however, things
> change.  Name resolution has a tendency to fail.  My Outlook
> 2000 only stays
> up for about 60 seconds and then it locks up.  NET USE says
> "The network
> name is no longer available."  I can access the Intranet, but
> only by IP
> address and not by regular URL.  SNA client tells me it
> cannot establish a
> connection.
>
> Any ideas?  Think this is also an MTU issue?  Or could it be
> something else?

I don't know, but I'd suspect WINS.  I'm not knowledgeable on WINS or the
packet sizes therein, but if WINS packets were being fragmented by your VPN
software, that'd produce what you describe.  Name resolution would work,
some of the time, but badly.

The other alternative is that your dial-up settings use a different name
server than your cable modem settings, so you're comparing apples to
oranges.



-- Craig

VPN is sponsored by SecurityFocus.COM




More information about the VPN mailing list