[ovirt-users] R: R: R: R: PXE boot of a VM on vdsm don't read DHCP offer

-----Messaggio originale----- Da: Fabian Deutsch [mailto:fdeutsch@redhat.com] Inviato: venerdì 3 luglio 2015 12:33 A: NUNIN Roberto Cc: Dan Kenigsberg; users(a)ovirt.org Oggetto: Re: [ovirt-users] R: R: R: PXE boot of a VM on vdsm don't read DHCP offer ----- Original Message ----- > Hi Dan, guys > > Sorry for very late follow-up, but we had a lot of other topics to fix just > before to go back on this one. > > We have tried another approach just to check if the kernel of the vdsm iso > image used to install the host could create the problem I've reported to the > list. > > Now we have reinstalled the same hardware with latest CentOS 7.1, fully > updated. > Installed vdsm, then joined the oVirt cluster. > > Well, we are observing the same behavior as before. > No DHCP offer is reaching the booting VM, and: > > brctl showmacs <bridge_if> show us the booting vm mac-address > tcpdump -I <bridge_if> show us the dhcp offer coming from dhcp server. > > We have also tried to remove ANY firewall rule. > > It isn't a PXE issue (gPXE 0.9.7) but only a DHCP process issue. Infact, if > we install a vm manually and assign a static IP, it works fine. > If we switch to dhcp, the vm don't get the dynamic one. > In this case, tcpdump on vm shows only the DHCP discovery, not the DHCP > offer. > > Any further suggestion/hint ? I've observed this behavior in bug https://bugzilla.redhat.com/show_bug.cgi?id=1230638 We also removed all firewall rules, checked iPXE and I also saw the requests going out, but no replies getting to the VM. But here it sounds like it isn't specific to bonds. After all I did not find the solution yet.

It is probably a good idea to install the oS with a static IP, and then switch to dhcp to then use tcpdump inside the vm to see what is reaching the inside.

- fabian > > RN > > > -----Messaggio originale----- > > Da: Dan Kenigsberg [mailto:danken@redhat.com] > > Inviato: lunedì 18 maggio 2015 16:14 > > A: NUNIN Roberto > > Cc: users(a)ovirt.org; ibarkan(a)redhat.com > > Oggetto: Re: R: [ovirt-users] R: PXE boot of a VM on vdsm don't read DHCP > > offer > > > > On Fri, May 08, 2015 at 03:11:25PM +0200, NUNIN Roberto wrote: > > > Hi Dan > > > Thanks for answering > > > > > > > > > > > > > Which kernel does the el7 host run? I think that Ido has seen a case > > > > where `brctl showmacs` was not populated with the VM mac, despite a > > > > packet coming out of it. > > > > > > Kernel is: 3.10.0-123.20.1.el7.x86_64, package is vdsm only. Brctl isn't > > available within vdsm only package. > > > > Could you try upgrading to a more up-to-date > > http://mirror.centos.org/centos- > > 7/7.1.1503/updates/x86_64/Packages/kernel-3.10.0- > > 229.4.2.el7.x86_64.rpm > > ? > > > > bridge-utils is a vdsm dependency. It must exist on your host. Please > > see if the mac of the vNIC shows up on `brctl showmacs` as it should. > > > > > > > > > > Can you tcpdump and check whether the bridge propogated the DHCP > > offer > > > > to the tap device of the said VM? Does the packet generated by > > > > `ether-wake MAC-of-VM` reach the tap device? > > > > > > Yes: host "see" the broadcast : > > > 0.000000 0.0.0.0 255.255.255.255 DHCP > > > 346 DHCP > > Discover - Transaction ID 0x69267b67 > > > It came from the right MAC: > > > Source: Qumranet_15:81:03 (00:1a:4a:15:81:03) > > > And it is tagged correctly: > > > 802.1Q Virtual LAN, PRI: 0, CFI: 0, ID: 3500 > > > > > > This is the offer, on the bond interface: > > > 1.012355 10.155.124.2 10.155.124.246 DHCP > > > 346 DHCP > > Offer - Transaction ID 0x69267b67 > > > Layer 2 info: > > > Ethernet II, Src: Cisco_56:83:c3 (84:78:ac:56:83:c3), Dst: > > Qumranet_15:81:03 (00:1a:4a:15:81:03) > > > Tagging on the bond: > > > 802.1Q Virtual LAN, PRI: 0, CFI: 0, ID: 3500 > > > > > > The tag is correctly removed when DHCP offer is forwarded over the > > bond.3500. > > > Here's the offer content, seems everything right: > > > > > > Client IP address: 0.0.0.0 (0.0.0.0) > > > Your (client) IP address: 10.155.124.246 (10.155.124.246) > > > Next server IP address: 10.155.124.223 (10.155.124.223) > > > Relay agent IP address: 10.155.124.2 (10.155.124.2) > > > Client MAC address: Qumranet_15:81:03 (00:1a:4a:15:81:03) > > > Client hardware address padding: 00000000000000000000 > > > Server host name: 10.155.124.223 > > > Boot file name: pxelinux.0 > > > Magic cookie: DHCP > > > > > > Nothing of this offer appear on the VM side. > > > > But does it show on the host's bridge? on the tap device? > > > > > > > > ether-wake -i bond0.3500 00:1a:4a:15:81:03 (started from the host) > > > reach the VM eth0 interface: > > > 2.002028 HewlettP_4a:47:b0 Qumranet_15:81:03 WOL > > > 116 > > MagicPacket for Qumranet_15:81:03 (00:1a:4a:15:81:03) > > > > > > Really strange behavior. > > > > > > Roberto > > Questo messaggio e' indirizzato esclusivamente al destinatario indicato e > potrebbe contenere informazioni confidenziali, riservate o proprietarie. > Qualora la presente venisse ricevuta per errore, si prega di segnalarlo > immediatamente al mittente, cancellando l'originale e ogni sua copia e > distruggendo eventuali copie cartacee. Ogni altro uso e' strettamente > proibito e potrebbe essere fonte di violazione di legge. > > This message is for the designated recipient only and may contain privileged, > proprietary, or otherwise private information. If you have received it in > error, please notify the sender immediately, deleting the original and all > copies and destroying any hard copies. Any other use is strictly prohibited > and may be unlawful. > _______________________________________________ > Users mailing list > Users(a)ovirt.org > http://lists.ovirt.org/mailman/listinfo/users >