I have recently replaced my external firewall with a Shorewall setup in a Xen DomU domain similar to what''s described in http://www.shorewall.net/XenMyWay.html. I''m using PCI pass-through to isolate two NICs in the Shorewall DomU, using one of the NICs for the net and one for my lan. I am also using a bridge off of a dummy interface (pdummy0 as the physical interface; dummy0 in Dom0) to provide network access to Dom0 and other DomU''s running on the same box. On at least an intermittent basis, if I try to download a large file in Dom0 (for example, upgrading a large Debian package via apt-get) the dummy bridge goes down and I lose all network connectivity to Dom0 and the non-Shorewall DomU''s. (I believe this may have also happened once during a download from a non-Shorewall DomU, but to date I''ve only recreated it with Dom0). I can generally restore function with the following commands in Dom0: "ifconfig dummy0 down; ifconfig pdummy0 down; ifconfig pdummy0 up; ifconfig dummy0 up" (on at least one occasion, I also had to correct the routing policies to send everything through dummy0). I have found no logs reflecting any error messages at the time of the network outages. Does anyone have any thoughts? Thanks, Seth Green ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference