Upping an interface without configuring it is not a “cardinal sin” but a sensible way to achieve auto-configuration, e.g. with IPv6 SLAAC (RFC 4862). If NetworkManager has troube with interfaces having only a link-local address, this is a bug in NetworkManager, not in libvirt; it should listen for router advertisements to decide if some interface has global connectivity or not. With network interfaces up by default, stateless containers can be easily auto-configured through the network with SLAAC, without any specific configuration from the host system. This reverts commit c3cf3c43a0bb2e0e4909c32821e20f607635ec85. Signed-off-by: Benjamin Cama <b.cama(a)kerlink.fr&gt; --- Hi, The patch that I propose to revert basically broke my workflow for light stateless containers, where they could be auto-configured on IPv6-only network through SLAAC. Of course, fully-fledged containers can bring up the interface themselves, but this behavior had previously been the default for quite some time, and is even indicated as default in src/conf/domain_conf.h ("Default link state (up)"). I cannot find any real justification for the patch I am reverting, and the bugzilla looks private so I can not comment on the NetworkManager behavior, which looks very buggy to me. Please tell me if you think this is wrong. Also, please Cc me, I am not subscribed. Regards. .mailmap | 1 + src/lxc/lxc_container.c | 7 +------ src/lxc/lxc_native.c | 10 ++++++---- 3 files changed, 8 insertions(+), 10 deletions(-) diff --git a/.mailmap b/.mailmap index 2f0fc901e..9dc3bff85 100644 --- a/.mailmap +++ b/.mailmap @@ -36,6 +36,7 @@ <gerd(a)egidy.de&gt; <lists(a)egidy.de&gt; <gerd(a)egidy.de&gt; <gerd.von.egidy(a)intra2net.com&gt; <benoar(a)dolka.fr&gt; <benjamin.cama(a)telecom-bretagne.eu&gt; +&lt;benoar(a)dolka.fr&gt; <b.cama(a)kerlink.fr&gt; <zhlcindy(a)linux.vnet.ibm.com&gt; <zhlcindy(a)gmail.com&gt; <serge.hallyn(a)canonical.com&gt; <serue(a)us.ibm.com&gt; <pritesh.kothari(a)sun.com&gt; <Pritesh.Kothari(a)Sun.COM&gt; diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c index 96fceaf1b..e546f0aaf 100644 --- a/src/lxc/lxc_container.c +++ b/src/lxc/lxc_container.c @@ -517,12 +517,7 @@ lxcContainerRenameAndEnableInterfaces(virDomainDefPtr vmDef, if (virNetDevSetName(veths[i], newname) < 0) goto cleanup; - /* Only enable this device if there is a reason to do so (either - * at least one IP was specified, or link state was set to up in - * the config) - */ - if (netDef->guestIP.nips || - netDef->linkstate == VIR_DOMAIN_NET_INTERFACE_LINK_STATE_UP) { + if (netDef->linkstate != VIR_DOMAIN_NET_INTERFACE_LINK_STATE_DOWN) { VIR_DEBUG("Enabling %s", newname); if (virNetDevSetOnline(newname, true) < 0) goto cleanup; diff --git a/src/lxc/lxc_native.c b/src/lxc/lxc_native.c index fdc03a57e..f77a2a910 100644 --- a/src/lxc/lxc_native.c +++ b/src/lxc/lxc_native.c @@ -349,10 +349,12 @@ lxcCreateNetDef(const char *type, if (VIR_ALLOC(net) < 0) goto error; - if (STREQ_NULLABLE(flag, "up")) - net->linkstate = VIR_DOMAIN_NET_INTERFACE_LINK_STATE_UP; - else - net->linkstate = VIR_DOMAIN_NET_INTERFACE_LINK_STATE_DOWN; + if (flag) { + if (STREQ(flag, "up")) + net->linkstate = VIR_DOMAIN_NET_INTERFACE_LINK_STATE_UP; + else + net->linkstate = VIR_DOMAIN_NET_INTERFACE_LINK_STATE_DOWN; + } if (VIR_STRDUP(net->ifname_guest, name) < 0) goto error; -- 2.11.0