Re: [Ddclient-support] DDClient Detecting a Second Gateway (Provider)???

[Larry H. <la...@gr...>]

Ingo:

On Mon, 1 Feb 2010, Ingo Schwarze wrote:

> Larry Houston wrote on Sat, Jan 23, 2010 at 09:35:29PM -0500:
>
>> I had assumed that I could just modify Static Gateways on all Computers
>> to switch between "Providers",
>
> That doesn't look like a good approach, it may cause all sorts of issues.
> For example, what about incoming connections?  They will continue to
> arrive via both providers, and you may end up with asymmetric routing,
> just to name one example.  Besides, what about your security policy,
> and how are you planning to enforce it in that kind of setup?

Using Wireshark I was able to Capture a TCP Stream in which there appears 
to be some Asymmetric Routing, leading DDClient to "Detect" the Public IP 
Address of Provider #2 instead of Provider #1!!!  I have attached a 
Capture of TCP Stream #581 to this Posting, although I do NOT know if the 
DDClient List "Accepts" Attachments???

Within Stream #581: MAC Address of Provider #1's Gateway (00:1c:10:9e:ae:2b)
                     MAC Address of Provider #2's Gateway (00:13:46:43:8c:4c)

All Frames leaving the Ubuntu Server are correctly targeting the MAC 
Address of Provider #1's Gateway, although of the Frames returning from 
checkip.dyndns.com (208.78.70.70) [Frames 2, 5, 6 & 12] have returned from 
the MAC Address of Provider #2's Gateway and have therefore DDClient 
has instead detected the Public IP Address of Provider #2!!!

If List Users have time to look at Stream #581's Capture, could they 
provide possible explanations as to why this Asymmetric Routing has 
occurred???  Within a Fully Switched Segment it would be more 
"Challenging" to verify from which Provider's Router the TCP Stream 
actually exited the Private Segment, although it might be that the TCP 
Stream actually left the Switched Segment via Router #2, even though 
initially the Frame was sent to Router #1's Gateway Interface???  If that 
was the case, then I might have created a "Dynamic" Routing Issue without 
know it???

Thanks again for everone's patience...

> Yours,
>  Ingo
>
> --
> Ingo Schwarze <isc...@as...> | Software Engineer | Framework Team
> Astaro AG | www.astaro.com | 76227 Karlsruhe | Germany
>