Problem with LAN networking between KVM guests after upgrade to 1.7

[ziggy]

First of all, hello to everyone.
After upgrading to 1.7, I'm experiencing really strange behavior (on on all servers I tried, so it probably isn't coincidence). Have all my guests located on a single bridge. I'm using this setup (10.100.0.0/24):

                      ----- station .1
                      ----- station .2
server .254 --
                      ----- station .X
                      ----- station .Y

Strange thing is: already installed guests (stations and server) can in most part communicate with each-other (https/ssh not working when I try to access host, worked before upgrade), and I can't perform new kickstart installations (station fails to mount nfs share located on server .254). Only thing that came to my mind, was to change MTU, but no change. Here's tcpdump:

host:~# tcpdump -i vmbr0 net 10.100.0.0/24
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on vmbr0, link-type EN10MB (Ethernet), capture size 96 bytes
01:25:01.098769 IP 10.100.0.254 > 224.0.0.251: igmp v2 report 224.0.0.251
01:25:28.322329 arp who-has 10.100.0.254 tell 10.100.0.10
01:25:28.322829 arp reply 10.100.0.254 is-at ae:2e:d8:2a:68:54 (oui Unknown)
01:25:28.323303 IP 10.100.0.10.53449 > 10.100.0.254.domain: 21321+ PTR? 10.0.100.10.in-addr.arpa. (42)
01:25:28.324107 IP 10.100.0.254.domain > 10.100.0.10.53449: 21321* 1/1/1 PTR[|domain]
01:25:28.332008 IP 10.100.0.10.36386 > 10.100.0.254.www: S 1895408749:1895408749(0) win 5840 <mss 1460,sackOK,timestamp 4294684757 0,nop,wscale 4>
01:25:28.332434 IP 10.100.0.254.www > 10.100.0.10.36386: S 2595285207:2595285207(0) ack 1895408750 win 5792 <mss 1460,sackOK,timestamp 4294846250 4294684757,nop,wscale 7>
01:25:28.332971 IP 10.100.0.10.36386 > 10.100.0.254.www: . ack 1 win 365 <nop,nop,timestamp 4294684758 4294846250>
01:25:28.332998 IP 10.100.0.10.36386 > 10.100.0.254.www: P 1:156(155) ack 1 win 365 <nop,nop,timestamp 4294684758 4294846250>
01:25:28.333434 IP 10.100.0.254.www > 10.100.0.10.36386: . ack 156 win 54 <nop,nop,timestamp 4294846251 4294684758>
01:25:28.461493 IP 10.100.0.254.www > 10.100.0.10.36386: . 1:1449(1448) ack 156 win 54 <nop,nop,timestamp 4294846380 4294684758>
01:25:28.461520 IP 10.100.0.254.www > 10.100.0.10.36386: P 1449:2091(642) ack 156 win 54 <nop,nop,timestamp 4294846380 4294684758>
01:25:28.461928 IP 10.100.0.10.36386 > 10.100.0.254.www: . ack 1449 win 546 <nop,nop,timestamp 4294684887 4294846380>
01:25:28.461973 IP 10.100.0.10.36386 > 10.100.0.254.www: . ack 2091 win 727 <nop,nop,timestamp 4294684887 4294846380>
01:25:28.470060 IP 10.100.0.254.www > 10.100.0.10.36386: F 2091:2091(0) ack 156 win 54 <nop,nop,timestamp 4294846388 4294684887>
01:25:28.470560 IP 10.100.0.10.36386 > 10.100.0.254.www: F 156:156(0) ack 2092 win 727 <nop,nop,timestamp 4294684896 4294846388>
01:25:28.470973 IP 10.100.0.254.www > 10.100.0.10.36386: . ack 157 win 54 <nop,nop,timestamp 4294846389 4294684896>
01:25:34.014911 arp who-has 10.100.0.254 tell 10.100.0.10
01:25:34.015427 arp reply 10.100.0.254 is-at ae:2e:d8:2a:68:54 (oui Unknown)
01:25:34.015981 IP 10.100.0.10.46247 > 10.100.0.254.sunrpc: S 1911351264:1911351264(0) win 5840 <mss 1460,sackOK,timestamp 4294690439 0,nop,wscale 4>
01:25:34.016511 IP 10.100.0.254.sunrpc > 10.100.0.10.46247: S 2602995126:2602995126(0) ack 1911351265 win 5792 <mss 1460,sackOK,timestamp 4294851934 4294690439,nop,wscale 7>
01:25:34.016978 IP 10.100.0.10.46247 > 10.100.0.254.sunrpc: . ack 1 win 365 <nop,nop,timestamp 4294690443 4294851934>
01:25:34.017008 IP 10.100.0.10.46247 > 10.100.0.254.sunrpc: P 1:45(44) ack 1 win 365 <nop,nop,timestamp 4294690443 4294851934>
01:25:34.017473 IP 10.100.0.254.sunrpc > 10.100.0.10.46247: . ack 45 win 46 <nop,nop,timestamp 4294851936 4294690443>
01:25:34.025795 IP 10.100.0.254.sunrpc > 10.100.0.10.46247: P 1:401(400) ack 45 win 46 <nop,nop,timestamp 4294851944 4294690443>
01:25:34.026325 IP 10.100.0.10.46247 > 10.100.0.254.sunrpc: . ack 401 win 432 <nop,nop,timestamp 4294690452 4294851944>
01:25:34.026711 IP 10.100.0.254.sunrpc > 10.100.0.10.46247: P 401:637(236) ack 45 win 46 <nop,nop,timestamp 4294851945 4294690452>
01:25:34.027158 IP 10.100.0.10.46247 > 10.100.0.254.sunrpc: . ack 637 win 499 <nop,nop,timestamp 4294690453 4294851945>
01:25:34.027177 IP 10.100.0.10.46247 > 10.100.0.254.sunrpc: F 45:45(0) ack 637 win 499 <nop,nop,timestamp 4294690453 4294851945>
01:25:34.027185 IP 10.100.0.10.927 > 10.100.0.254.22774: UDP, length 116
01:25:34.027562 IP 10.100.0.254.sunrpc > 10.100.0.10.46247: F 637:637(0) ack 46 win 46 <nop,nop,timestamp 4294851946 4294690453>
01:25:34.027941 IP 10.100.0.10.46247 > 10.100.0.254.sunrpc: . ack 638 win 499 <nop,nop,timestamp 4294690453 4294851946>
01:25:34.083214 IP 10.100.0.254.22774 > 10.100.0.10.927: UDP, length 76
01:25:34.083702 IP 10.100.0.10.929 > 10.100.0.254.sunrpc: UDP, length 56
01:25:34.084201 IP 10.100.0.254.sunrpc > 10.100.0.10.929: UDP, length 28
01:25:34.084919 IP 10.100.0.10.1372081357 > 10.100.0.254.nfs: 40 null
01:25:34.085467 IP 10.100.0.254.nfs > 10.100.0.10.1372081357: reply ok 24 null
01:25:34.784460 IP 10.100.0.10.1372081357 > 10.100.0.254.nfs: 40 null
01:25:34.784858 IP 10.100.0.254.nfs > 10.100.0.10.1372081357: reply ok 24 null
01:25:36.184002 IP 10.100.0.10.1372081357 > 10.100.0.254.nfs: 40 null
01:25:36.184489 IP 10.100.0.254.nfs > 10.100.0.10.1372081357: reply ok 24 null
01:25:38.984614 IP 10.100.0.10.1372081357 > 10.100.0.254.nfs: 40 null
01:25:38.985140 IP 10.100.0.254.nfs > 10.100.0.10.1372081357: reply ok 24 null
01:27:07.745797 IP 10.100.0.254 > 224.0.0.251: igmp v2 report 224.0.0.251
^C
44 packets captured
44 packets received by filter
0 packets dropped by kernel


host:~# pveversion -v
pve-manager: 1.7-10 (pve-manager/1.7/5323)
running kernel: 2.6.35-1-pve
proxmox-ve-2.6.35: 1.6-7
pve-kernel-2.6.32-4-pve: 2.6.32-28
pve-kernel-2.6.35-1-pve: 2.6.35-7
qemu-server: 1.1-25
pve-firmware: 1.0-9
libpve-storage-perl: 1.0-16
vncterm: 0.9-2
vzctl: 3.0.24-1pve4
vzdump: 1.2-9
vzprocps: 2.0.11-1dso2
vzquota: 3.0.11-1
pve-qemu-kvm: 0.13.0-2
ksm-control-daemon: 1.0-4