In the presence of firewalls which improperly block ICMP Unreachable
(including Fragmentation Required) messages, Path MTU Discovery is
prevented from working.
A workaround is to handle IPv4 payloads opaquely, ignoring the DF bit--as
is done for other payloads like AppleTalk--and doing transparent
fragmentation and reassembly.
Redux includes the enforcement of mutual exclusion between this feature
and Path MTU Discovery as suggested by Alexander Duyck.
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
22a59be8b7