[nzlug] Virtualization + ethernet/ping issues.

[Mark Goldfinch]

Hi Michael,

Michael Hutchinson wrote:
> Here goes my strace: obfuscation of client IP only (XX)
>
> gettimeofday({1202864466, 216269}, NULL) = 0
> gettimeofday({1202864466, 216412}, NULL) = 0
> sendmsg(3, {msg_name(16)={sa_family=AF_INET, sin_port=htons(0),
> sin_addr=inet_addr("192.168.51.XX")},
> msg_iov(1)=[{"\10\0\223\5\nP\v\321RA\262G\\M\3\0\10\t\n\v\f\r\16\17\20".
> .., 64}], msg_controllen=0, msg_flags=0}, 0) = 64
> recvmsg(3, 0xbfffeb40, 0)               = -1 EAGAIN (Resource
> temporarily unavailable)
> gettimeofday({1202864467, 216392}, NULL) = 0
> gettimeofday({1202864467, 216524}, NULL) = 0
> sendmsg(3, {msg_name(16)={sa_family=AF_INET, sin_port=htons(0),
> sin_addr=inet_addr("192.168.51.XX")},
> msg_iov(1)=[{"\10\0\"\4\nP\v\322SA\262G\314M\3\0\10\t\n\v\f\r\16\17\20".
> .., 64}], msg_controllen=0, msg_flags=0}, 0) = 64
> recvmsg(3, 0xbfffeb40, 0)               = -1 EAGAIN (Resource
> temporarily unavailable)
>   

As previously mentioned by Rex, I think your reply is getting lost 
between the network and ping.

Could you have the packet being returned with an incorrect MAC address 
(and hence the Linux virtual machine doesn't pay attention to it)?

The way we can test whether the MAC addresses are all correct is to 
create a pcap capture file and inspect it using wireshark.  Have a look 
and see whether your host's MAC address is consistently present within 
the ICMP packets?

Thanks,
Mark.