Hello, I have a big problem: Dom0 is centos5.1, domU are centos5.1. My setup is really simple, the only thing is that I give 3 nics to the domU so I use a modified network script (which has worked since january... since fedora 6): " #!/bin/sh dir=$(dirname "$0") "$dir/network-bridge" "$@" vifnum=0 "$dir/network-bridge" "$@" vifnum=1 "$dir/network-bridge" "$@" vifnum=2 " So I have updated my xen dom0 from 3.0.3-rc5-8.1.15.el5 to 3.1.0-53.1.4.el5 (and kernel-xen 2.6.18-8.1.15.el5xen to 2.6.18-53.1.4.el5xen) and now my domU cant access the network. The interfaces are good in the domU, all seems to be ok but there are no connectivity at all (no arp entries). This message shows up on the dom0 each time I launch a domU: blkback: ring-ref 9, event-channel 7, protocol 1 (x86_64-abi) Do someone know what is happening ? this is very embarrassing after a simple upgrade... Hopefully I have another identical server (Centos 5.0 with 5.1 domUs) which is still in 3.0 but I cant stay not updated. Thanks for any help. xm info: host : host.foo.com release : 2.6.18-53.1.4.el5xen version : #1 SMP Fri Nov 30 01:21:23 EST 2007 machine : x86_64 nr_cpus : 4 nr_nodes : 1 sockets_per_node : 2 cores_per_socket : 1 threads_per_core : 2 cpu_mhz : 2992 hw_caps : bfebfbff:20100800:00000000:00000180:0000641d total_memory : 4095 free_memory : 3246 xen_major : 3 xen_minor : 1 xen_extra : .0-53.1.4.el5 xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p xen_pagesize : 4096 platform_params : virt_start=0xffff800000000000 xen_changeset : unavailable cc_compiler : gcc version 4.1.2 20070626 (Red Hat 4.1.2-14) cc_compile_by : mockbuild cc_compile_domain : cc_compile_date : Fri Nov 30 00:37:12 EST 2007 xend_config_format : 2