I''ve set up my a xen server as my LAN gateway, which has a DSL connection and does NAT masquerade for the LAN, and I run several domU on the server with routing network settings. All things work smoothly except the xenU domains can''t reach the internet with TCP: ping works fine, telnet can establish connection and receive server packets, but real data packets sent through ppp0 shows checksum error (tcpdump -vv shows cksum incorrect). Then I found the problem on xensource community faq, and after I followed his instruction to turned off the TX checksumming, my network works properly. http://wiki.xensource.com/xenwiki/XenFaq#head-4ce9767df34fe1c9cf4f85f7e07cb10110eae9b7 And here''s a post describing some details, could you guys fix the problem in xen0 kernel so we won''t get stuck by this problem again? http://lists.xensource.com/archives/html/xen-users/2006-04/msg00032.html -- regards, Gary Shi