[libvirt] FW: macvtap not working on rhel 6.1 x86 machine

Amit Tewari Amit.Tewari at nechclst.in
Thu Dec 15 09:50:43 UTC 2011

Hi all,


My test environment

Host os=rhel6.1 x86 machine

Guest os = rhel6.1


Kvm hypervisor


I am creating macvtap interface on host machine 

ip link add link eth1 name macvtap0 type macvtap

ip link set macvtap0 up


ip link show macvtap0

25: macvtap0 at eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
pfifo_fast state UNKNOWN qlen 500

    link/ether a2:70:4e:05:4a:4e brd ff:ff:ff:ff:ff:ff



Now when use arp -a to check macvtap0 hardware address entry it shows

? ( at <incomplete> on macvtap0



If I assign ip address to macvtap and then ping on network , it says
"destination not reachable"

ping -I macvtap0


PING ( from macvtap0: 56(84) bytes of data.

>From icmp_seq=2 Destination Host Unreachable

>From icmp_seq=3 Destination Host Unreachable



If I use tcpdump -I eth1 it shows packets

14:42:39.967158 ARP, Request who-has tell, length 28

14:42:39.967257 ARP, Reply is-at 00:16:35:65:b5:1e (oui
Unknown), length 46

14:42:40.967167 ARP, Request who-has tell, length 28

14:42:40.967229 ARP, Reply is-at 00:16:35:65:b5:1e (oui
Unknown), length 46


So macvtap0 is unknown interface. Request does go to eth1 inteface.


Please let me know redhat 6.1 support macvtap or not?...


I have to use it for kvm virtual machine..


The contents of this e-mail and any attachment(s) are confidential and
for the named recipient(s) only.  
It shall not attach any liability on the originator or NECHCL or its 
affiliates. Any views or opinions presented in  
this email are solely those of the author and may not necessarily reflect the 
opinions of NECHCL or its affiliates.  
Any form of reproduction, dissemination, copying, disclosure, modification, 
distribution and / or publication of  
this message without the prior written consent of the author of this e-mail is 
strictly prohibited. If you have  
received this email in error please delete it and notify the sender 
immediately. . 

More information about the libvir-list mailing list