Archived from groups: comp.security.firewalls (More info?)
In article <1127238121.407805.194340@z14g2000cwz.googlegroups.com>,
mess <iftikharm_50001@yahoo.com> wrote:
:My ISP is putting firewall I can not connect any PC to Phone dialer and
:I can not open many sites on web. How to break?
I don't know what you mean about the phone dialer -- it is far
from easy to have a firewall enforce anything about what you do
with a different network interface that isn't talking to the ISP.
(Not necessarily -impossible-: Cisco and other manufacturers are
working on mechanisms that "audit" your PC before allowing a connection;
for example, the security policy being enforced might include that
you aren't relaying traffic for other systems since those other systems
might not be secure.)
If you cannot open many sites on the web, then the ISP might be
filtering what you can reach -- this would be rather unusual unless you
live in a country such as China, or your ISP is required by law to
block access to (e.g.) Nazi sites -- or unless your "ISP" is
not a commercial ISP but is instead really your workplace.
More plausible is that the connection changed in such a way that a
portion of each packet is not consumed by overhead, and that you have
to lower your MTU (Maximum Transfer Unit) by some amount in order that
the total after-overhead packet size is within range. If your ISP has
PPPoE then you might need to reduce from 1500 to 1492. If there is
now a VPN connection between you and the ISP, your MTU might have to
go down further yet, into the 1350 range plausibly.
--
When Love is gone, there's always Justice.
When Justice is gone, there's always Force.
When Force is gone, there's always Mom. -- Laurie Anderson
