Bill    

The problem is similar to what you mention in 2).

DNS2GO is setting a TTL on the URL to 15 seconds.  The TP is using a DNS server 
which is not honoring the TTL.  When the IP changes, they still point to the 
old (invalid) IP.

Why spend $600.00 per year extra when it should not be necessary?




To:                     [email protected]
From:                   "impulse_telecom" <[EMAIL PROTECTED]>
Date sent:              Mon, 09 Apr 2007 19:13:46 -0000
Subject:                [EDI-L] Re: AS2 and Dynamic IPs

> I think I'd need a little more information to determine the exact 
> cuase of problems in this AS2 set-up.
> 
> Recommendations:
> 1.  If at all possible, get the Internet service provider to set up 
> a Static IP address.  Even cut-rate DSL service from AT&T is 
> available with a Static IP address for $49.95 per month.
> 
> 2.  I like Zone Edit (www.zoneedit.com) if you need to host DNS 
> externally.  If you can get a static IP, you don't need to worry 
> quite as much about the canonical (non-numeric) name of your AS2 
> server.  However... some firewalls look up DNS and may refuse the 
> connection if the forward and reverse resolution don't math.  That 
> is to say you claim you are wonder-as2.abc.com and that resolves to 
> 64.217.208.6.  The firewall then resolves 64.217.208.6 back and gets 
> the answer host6-dsl.denver.sbc.com (This is a ficticious example 
> for illustration only).  Since host6-dsl.denver.sbc.com doesn't 
> match wonder-as2.abc.com, the firewall drops the connection.  I 
> beleive Zoneedit still allows you to tailor some of your domain's 
> SOA (start of authority) record vaules, such as the time-to-live and 
> mandatory refresh interval.
> 
> Some proxy/firewalls and some Windows products ignore the SOA values 
> and cache DNS data for whatever interval they like.  In particualr, 
> I've seen problems wiht Win2k applicaitons where Windows itself may 
> properly honor the SOA, but the application caches DNS data 
> separately from the O/S.  There isn't much you can do to fix broken 
> behavior.
> 
> I've usually seen the check for forward/reverse DNS matching used 
> priamrily on mail servers, since e-mail has essentially no 
> authentication.  The idea is that spammers are too lazy to get 
> properly registered DNS for the PCs they've co-opted for their 
> networks.  The firewall administrator might have turned on the DNS 
> check for all services, not just e-mail.
> 
> 3.  Be sure your in-bound and out-bound firewall rules are correct.  
> The firewall administrator for either side might have ranges of 
> excluded ports that you or the other side are hitting some of the 
> time when opening out-bound connections.
> 
> 4.  On the AS2 scene, try setting your MDNs to synchronous.  This is 
> handny if your IP address is bound to move unexpectedly.  The 
> initating AS2 server will maintain the initial TCP connection open 
> until the recipient issues the MDN response.  Part of the headers 
> have the reply-to address written in, so if you have an IP address 
> written into the header, and it changes, then without synchronous 
> MDNs, the repsonse may go back to the wrong IP address.  This can 
> lead to weird errors, and I've seen Drummond certified servers 
> exhibit various behaviors.  In the case of an async MDN and IP 
> moving, the receiver may try to connect back to what it thinks is 
> the correct address, but nobody is there.  I've seen one product 
> consider trying to deliver an MDN as sufficient, whether or not the 
> sender got the reply.  Meanwhile, the sender never gets the MDN, and 
> keeps re-sending the same message.  Using AS2 doesn't prevent 
> duplicates in such a case; lesson always check your document control 
> numbers!
> 
> Even if you have synchronous MDNs, you may still encounter 
> problems.  Again, it depends on the particular AS2 software running 
> at the recipient.  Some implementations don't bother to look at the 
> reply-to address if the MDN request is synchronous.  Other 
> implementations will send a negative MDN and reject the data if the 
> reply-to address doesn't match where the connection is actually 
> coming from.
> 
> For something that is allegedly standardized, AS2 has too many 
> configuration options and despite the fact (or becuase of the fact) 
> it has an IETF RFC, it is too easy to mess up the configuration.
> 
> Here is another real-world thing I've run into a few times.  Some 
> AS2 implementations seem very sensitive to dropped packets.  I had 
> one big retail partner that failed almost every attempt to pass 
> data.  I worked with their Internet person and tried lots of things 
> without success.  What finally made the connection work reliably was 
> to enable compression.  Go figure.
> 
> Some AS2 software suites are easier to work with than others.  Many 
> AS2 users are fixated on Drummond certification, which requires you 
> to plunk down a lot of money for a certified product.  By the time 
> you find out you don't like your AS2 hub, the money is spent.  If 
> you can, set up a lab with a few servers, and try several competing 
> AS2 product trial versions before you commit to a vendor.
> 
> --
> Bill Mayhew
> 
> --- In [email protected], Earl Wertheimer <[EMAIL PROTECTED]> wrote:
> >
> > Pete
> > 
> > > Or, if you can assign the address to be non-numeric, you can 
> *very*
> > > inexpensively pick up an account with an IP forwarding company.  
> No-ip.com
> > > or DNS2GO.com work just fine.  
> > 
> > No, that's exactly the problem we are having.  We ARE using 
> DNS2GO, but there 
> > seems to be a very long delay for the TP's DNS servers to get the 
> new IP.
> > 
> > What I need to know is if there is a way to force their DNS server 
> to refresh 
> > the IP sooner...  DNS2Go can update the IP on their own DNS 
> servers almost 
> > immediately because of the client software that is always checking 
> and 
> > reporting any changes.  
> > 
> > There is still a propagation delay amongst all the other DNS 
> servers,  
> > especially if the TP has their own DNS server...
> > 
> > I haven't checked if DNS2GO had any problems, but I've been able 
> to use the URL 
> > for remote access and AS2 tests, so I don't think that they are 
> the problem.
> > 
> > 
> > 
> > 
> > > -----Original Message-----
> > > From: [email protected] [mailto:[EMAIL PROTECTED] On 
> Behalf Of Earl
> > > Wertheimer
> > > Sent: Thursday, April 05, 2007 1:34 PM
> > > To: Mary DeGroot; [email protected]
> > > Subject: Re: [EDI-L] AS2 and Dynamic IPs
> > > 
> > > Dale & Mary,
> > > 
> > > thanks
> > > 
> > > The TP is claiming that the dynamic IP is the problem.  
> > > 
> > > I 'ping' client AS2 servers regularly, to make sure that they 
> are online.
> > > If 
> > > they are not, then an email is sent to the admin...
> > > 
> > > I suspect some kind of 'caching' problem.  I am not familiar 
> with the DNS
> > > TTL 
> > > (Time To Live) settings, but it may be possible that the TP is 
> storing the 
> > > current IP in their DNS server, and when the client's IP 
> changes, the TP is 
> > > still pointing to the old (and incorrect) IP.
> > > 
> > > They have limited control over their DNS server, so I have to be 
> sure about
> > > the 
> > > problem and possible solutions.
> > > 
> > > I would like to resolve the problem without involving the TP too 
> much, if 
> > > possible.  
> > > 
> > > The last resort would be to tell my client to obtain a fixed 
> IP...
> > > 
> > > 
> > > 
> > > -------------- Original message ---------------
> > > Date sent:        Thu, 05 Apr 2007 11:06:58 -0500
> > > From:     "Mary DeGroot" <[EMAIL PROTECTED]>
> > > To:       "Earl Wertheimer" <[EMAIL PROTECTED]>
> > > Send reply to:    [EMAIL PROTECTED]
> > > Subject:  Re: [EDI-L] AS2 and Dynamic IPs
> > > 
> > > 
> > > If BizLink is not using an HTTP proxy, it is using the DNS 
> services on the
> > > local machine to resolve the URL to an IP address. In this case, 
> the TP
> > > should go to the BizLink machine and try to access your URL. 
> Take BizLink
> > > out of the picture by trying these things:
> > > 1. Try to access the URL through a browser window. The AS2 
> servers that I
> > > have used will usually come back with a splash screen or some 
> sort of
> > > indication that you've hit an AS2 server when using a browser. 
> If it goes
> > > through with the browser on the BizLink machine, then it's a 
> BizLink
> > > problem. The problem might be with how they entered the URL into 
> BizLink
> > > since the only difference in resolving the URL would be with the 
> URL
> > > entered. If you can't get through via the browser, it's probably 
> a DNS
> > > service/network issue.
> > > 2. Try to ping or tracert the URL from the BizLink machine. Ping 
> should at
> > > least resolve to your current IP address even if ping is turned 
> off on your
> > > server. Tracert should go through to your current IP address. 
> Again, if it
> > > doesn't go through they probably have a DNS services / network 
> issue.
> > > 
> > > If the BizLink machine is pointing to a forward HTTP proxy, then 
> they need
> > > to do the above tests from the HTTP proxy machine. They should 
> also try to
> > > access the URL from a browser on the BizLink machine. The 
> browser needs to
> > > be configured to use the forward HTTP proxy that the BizLink 
> machine is
> > > using. Make sure that they can get through their proxy and to 
> your URL. They
> > > need to make sure that the HTTP proxy is set up properly (proxy 
> URL, proxy
> > > User ID, proxy password) in BizLink and that the outbound 
> transport for you
> > > is configured to use the proxy.
> > > 
> > > HTH
> > > Mary
> > > 
> > > 
> > > > 
> > > > 
> > > > Has anyone had problem using Dynamic DNS redirection for AS2?
> > > > 
> > > > One of our clients is using DNS2GO to redirect their URL 
> > > > (www.coname.dns2go.com) to their current IP address.
> > > > 
> > > > We do this because their ISP does not give them a fixed IP 
> (which is much 
> > > > cheaper).
> > > > 
> > > > For the last week, one of their TPs has been unable to connect.
> > > > The TP is using Inovis Bizlink for their AS2. Our client is 
> using
> > > IP*Works.
> > > > 
> > > > We have never had problems before...
> > > > 
> > > > comments???
> > > > 
> > > > Earl Wertheimer
> > > > [EMAIL PROTECTED]
> > > > http://www.spe-edi.com
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > Earl Wertheimer
> > > [EMAIL PROTECTED]
> > > http://www.spe-edi.com
> > > 
> > > 
> > > 
> > > ...
> > > Please use the following Message Identifiers as your subject 
> prefix:
> > > <SALES>, <JOBS>, <LIST>, <TECH>, <MISC>, <EVENT>, <OFF-TOPIC>
> > > 
> > > Job postings are welcome, but for job postings or requests for 
> work: <JOBS>
> > > IS REQUIRED in the subject line as a prefix. 
> > > Yahoo! Groups Links
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > __________ NOD32 2169 (20070405) Information __________
> > > 
> > > This message was checked by NOD32 antivirus system.
> > > http://www.eset.com
> > > 
> > > 
> > 
> > 
> > 
> > -- Earl Wertheimer / [EMAIL PROTECTED] / http://www.spe-edi.com
> >
> 
> 
> 
> 
> ...
> Please use the following Message Identifiers as your subject prefix: <SALES>, 
> <JOBS>, <LIST>, <TECH>, <MISC>, <EVENT>, <OFF-TOPIC>
> 
> Job postings are welcome, but for job postings or requests for work: <JOBS> 
> IS REQUIRED in the subject line as a prefix. 
> Yahoo! Groups Links
> 
> 
> 
> 
> 
> 
> __________ NOD32 2175 (20070409) Information __________
> 
> This message was checked by NOD32 antivirus system.
> http://www.eset.com
> 
> 

Earl Wertheimer
[EMAIL PROTECTED]
http://www.spe-edi.com



...
Please use the following Message Identifiers as your subject prefix: <SALES>, 
<JOBS>, <LIST>, <TECH>, <MISC>, <EVENT>, <OFF-TOPIC>

Job postings are welcome, but for job postings or requests for work: <JOBS> IS 
REQUIRED in the subject line as a prefix. 
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