Hi, Are you using the proper traffic labels for all the traffic types in the physical network? Since you have multiple PIFs on XenServer you must specify traffic labels on zone's physical network for different traffics(guest,management,public and storage) to go through the intended PIFs on XenServer.
Please refer to CS admin guides on setting traffic labels. Thanks, Sanjeev -----Original Message----- From: Martin Emrich [mailto:martin.emr...@empolis.com] Sent: Tuesday, November 04, 2014 5:57 PM To: users@cloudstack.apache.org Subject: Re: GRE isolated network: wrong interface? Hi! Am 04.11.2014 12:46, schrieb Erdősi Péter: > Hmm.. you mean isolated guest network right? > If yes, the IP subnet can be changed, if the user define guest network > (not auto, when first vm started) There is an option to: Guest > Gateway, and Guest Netmask, and if it filled, the sysvm will use that > subnet... No, I do not mean the guest network (which works fine). I mean the network between the XenServers, where the guest traffic is carried. My XenServers have the following interfaces: - MANAGEMENT - GUEST (which should be used for GRE-encapsulated private traffic) - PUBLIC - ISCSI1 - ISCSI2 All except PUBLIC have IP addresses: MANAGEMENT obviously for XenCenter and XAPI, ISCSI1/2 for the multipathed shared storage, and GUEST (intended for GRE traffic, although it is nowhere mentioned that the interface must have IP addresses). The intended behaviour is that Cloudstack instructs the OpenVSwitches within the XenServer nodes to build the GRE tunnels between VMs within the same Cloudstack isolated Network across the GUEST interface. But CloudStack chooses one of the other interfaces (MANAGEMENT or ISCSI) to carry the GRE traffic. You can see this with "ovs-vsctl show" on one of the XenServers with currently running instances: # ovs-vsctl show ... Bridge "xapi4" fail_mode: standalone Port "vif1.0" Interface "vif1.0" Port "t1074-8-9" Interface "t1074-8-9" type: gre options: {key="1074", remote_ip="10.33.1.5"} Port "xapi4" Interface "xapi4" type: internal ... Here you see the remote IP of the other XenServer for the GRE tunnel. But the IP is wrong, it is on the first ISCSI network. This works, but of course we want to isolate storage traffic from guest traffic, so Cloudstack should do as expected and use the "GUEST" interface ip of the peer XenServer as remote_ip. Ciao Martin