Description of problem: xenpv-win net driver can not do tcp with other guests on the same hyperhost. Version-Release number of selected component (if applicable): xenpv-win-1.2.0-1 How reproducible: 100% Steps to Reproduce: 1. Install a Windows 7 (x86 or x64 as your wish) 2. Install the xenpv-win inside guest 3. reboot and reboot 4. telnet otherguest 22, (otherguest is linux xen domu on the same hyperhost) Actual results: connection established, but no welcome message of openssh display. Expected results: welcome message such as 'SSH-2.0-OpenSSH_4.3' shows. Additional info:
BTW: 1. I can not do tcp with the hypervisor host. 2. I can do tcp with other hosts inside the Windows guest.
Same here with xenpv-win-1.3.1-1.el5 XP Home SP3 guest cannot access apache running on a centos guest under the same hypervisor. Tried with IE8 and Wget. All guests are connected to br0, no firewall. Other hosts on the LAN/internet work fine.
There is a workaround. Add a DWORD value NetworkNoChecksumOffload and set it to 1 under HKLM\SYSTEM\CurrentControlSet\Services\rhelscsi.
The workaround worked, thanks!
(In reply to comment #3) > There is a workaround. Add a DWORD value NetworkNoChecksumOffload and set it > to 1 under HKLM\SYSTEM\CurrentControlSet\Services\rhelscsi. Paolo, Do you think this bug is duplicate of bug 617435? Regards, Pengzhen
No, that one was about guest->host and host->guest communication and affected all Windows versions. This is only for Windows 2003 and XP. These versions require the TCP and/or UDP (do not remember the details, sorry) checksums to be correct when offloading is on, while Xen leaves them blank.
Patch included as part of bug 718329, leaving bug open as TestOnly.
*** Bug 731293 has been marked as a duplicate of this bug. ***
Documented at https://access.redhat.com/kb/docs/DOC-65073
Verify this fix with xenpv-win-1.3.12-3.el5. Host: 2.6.18-298.el5xen xen-3.0.3-135.el5 Guest: Win7 Win2k3 Steps: 1. Check that the tx-checksumming of the host is on: # ethtool -k eth0 Offload parameters for eth0: Cannot get device rx csum settings: Operation not supported Cannot get device udp large send offload settings: Operation not supported rx-checksumming: off tx-checksumming: on scatter-gather: on tcp segmentation offload: on udp fragmentation offload: off generic segmentation offload: off generic-receive-offload: off 2. check that no DWORD value NetworkNoChecksumOffload set in Win guest register table 3. install winscp on Win guest, use winscp to connect the host: 1) local Hypervisor 2) Linux host on the same Hypervisor 4. use ftp connect between the Win guests on the same host All above tests PASS with file transferred successfully.
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: Cause - Different requirements imposed by Linux and Windows on the implementation of checksum offloading. Consequence - A Windows machine running with paravirtualized drivers will not be able to communicate with other guests running on the same host. Fix - Checksum offloading has been disabled in this release of the drivers. Result - Communication between Windows guests running on the same host will work correctly.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHBA-2012-0195.html