internet connection sharing problem

  • Thread starter Thread starter Awoll
  • Start date Start date
A

Awoll

Hello,

I don't think this is your average ICS problem. I'm using win 2k server as
the ics host machine. DNS and DHCP disabled so that there is no conflict
with ICS. Connect using enternet 300 software to SBC dsl service. Everything
was working fine untill the other day. Network could use all funtions of the
internet with no problems. The other morning i could no longer access a few
web sites. To be specific: ebay, shastasmart, some disney sites, and now
even microsoft.com is hard to access. Some times it will work, other times
not. The client machines are all set to auto for ip config. Anyone got any
ideas why i can only browse half the net. I get a error stating that server
could not be found, or dns problem. The sites all work fine from the host
machine running ICS. I ping the sites from a client machine and it does
retrive the proper ip addy for the site. Atleast i think it is, becuase
pinging from the host returns the same address. Any help would be cool. I've
spent 3 days working on this and am about to go mad. LOL

Thanks,

Aaron
 
ebay is the giveaway. You are suffering from the problem that ICS is
a Black Hole Router. Read about Black Hole Routers here:
http://support.microsoft.com/?id=314825

To see the Black Hole behavior, try these two commands from a DOS
window on the Gateway machine and the other machines:

ping www.ebay.com -f -l 1472
ping www.ebay.com -f -l 1432

Also try www.google.com and www.abcnews.go.com and
www.shastasmart.com. The gateway machine for 1472 will respond
"packet needs to be fragmented but DF Set." All other setting will
respond "Request timed out." When browsing, the gateway machine sees
the message and reconnects with a smaller MTU. Bu the gateway never
relays this information to the ICS clients.

The workaround is to use Method 3 from the article and set the MTU
size of the client machines to 1460 (=1432+28).

I'm hoping that one of the pros here will pick up on this and get
Microsoft to fix ICS.
 
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