Hi all:

I have some kvm host(rhel 6.4, 2.6.32-358.0.1.el6.x86_64), I ran several windows guest on it(more than 10 guest on one host and the guest os are win7-32/win7-64/win2k8), but the guest network kept down automatically, lost package. I tried virtio drive and e1000 drive,but it didn't work. However, when I run cmd.exe ping some other subnet ip it worked.

The host and guest are connected by bridge.

Here is some configure infomation of my guest:

<mac address='aa:aa:aa:49:39:71'/&! gt;

</interface>

brctl show as follow:

kvmbr2 8000.b8ca3a5cbea2 no eth2

vnet0

vnet11

vnet13

vnet15

vnet17

vnet19

vnet2

vnet21

vnet23

vnet25

vnet27

vnet29

vnet5

vnet7

vnet9

The /etc/sysctl.conf configure as follow:

# Kernel sysctl configuration file for Red Hat Linux

# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and

# sysctl.conf(5) for more details.

# Controls IP packet forwarding

net.ipv4.ip_forward = 0

#net.ipv4.ip_forward = 1

# Controls source route verification

net.ipv4.conf.default.rp_filter = 1

# Do not accept source routing

net.ipv4.conf.default.accept_source_route = 0

# Controls the System Request debugging functionality of the kernel

kernel.sysrq = 0

# Controls whe! ther core dumps will append the PID to the core filename.

# Useful for debugging multi-threaded applications.

kernel.core_uses_pid = 1

# Controls the use of TCP syncookies

net.ipv4.tcp_syncookies = 1

# Disable netfilter on bridges.

# Controls the default maxmimum size of a mesage queue

kernel.msgmnb = 65536

# Controls the maximum size of a message, in bytes

kernel.msgmax = 65536

# Controls the maximum shared segment size, in bytes

kernel.shmmax = 68719476736

# Controls the maximum number of shared memory segments, in pages

kernel.shmall = 4294967296

########### add by operation V1.0 begin ############

net.ipv4.ip_local_port_range = 32768 65000

net.core.rmem_max = 8388608

net.core.wmem_max = 8388608

net.ipv4.tcp_rmem = 4096 87380 8388608

net.ipv4.tcp_wmem = 4096 65536 8388608

net.ipv4.tcp_max_syn_backlog = 8192

net.ipv4.tcp_window_scaling = 0

net.ipv4.tcp_sack = 0

net.ipv4.t! cp_timestamps = 0

kernel.panic =! 5

vm.swappiness = 51

########### add by operation V1.0 end ############

net.bridge.bridge-nf-call-ip6tables = 0

net.bridge.bridge-nf-call-iptables = 0

net.bridge.bridge-nf-call-arptables = 0

#add by wdh

#net.ipv4.conf.all.proxy_arp = 1