IPENCAP Problem

[Barney Wolff]

On Tue, Jan 06, 2004 at 04:20:25PM -0500, tomt at callcds.com wrote:
> The problem
> I have 5 buildings that are connected via point-to-point wireless.  The
> cost of dedicated lines within this town were so high that wireless was an
> excellent option.  The wireless is in place and working however we are
> going back to secure the wireless cloud so that it cannot be used by
> unauthorized people.  The internet connection for all buildings is located
> at Building A so all machines need to route across the wireless to the
> internet.
> 
> The solution
> 5 PCs running FreeBSD 5.1-Release using 2 network cards apiece and running
> IP-ENCAP between nodes with the tunnel being encrypted with IPSEC.
> Routing on each gateway that sends its traffic to the headend at Building A
> 
> I have all this working except for this problem
> The PROBLEM
> Certain websites are not accessible
> sears.com
> msnbc.com
> microsoft.com
> drudgereport.com
> 
> Other websites will work normally
> freebsd.org
> slashdot.org
> ebay.com
> 
> What seems to be the problem
> Each of the websites that I listed have round-robin DNS enabled and have
> multiple A records for the website

I'd suspect MTU issues rather than multiple A records.  Try setting the
MTU of the link to the Internet to 1400.  If that works you can fine
tune it.

-- 
Barney Wolff         http://www.databus.com/bwresume.pdf
I'm available by contract or FT, in the NYC metro area or via the 'Net.