0006665: Guests can ping each other but not ssh when using MACVTAP + virtio device - CentOS Bug Tracker

ID	Project	Category	View Status	Date Submitted	Last Update

0006665	CentOS-6	qemu-kvm	public	2013-09-13 09:33	2013-10-25 11:21

Reporter	panda84
Priority	normal	Severity	major	Reproducibility	always
Status	new	Resolution	open
Platform	Intel PC	OS	CentOS	OS Version	6.4
Product Version	6.4
Target Version		Fixed in Version

Summary	0006665: Guests can ping each other but not ssh when using MACVTAP + virtio device
Description	CentOS host updated @ 13 sep 2013 # uname -a Linux boltzmann 2.6.32-358.6.2.el6.x86_64 #1 SMP Thu May 16 20:59:36 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux # rpm -q qemu-kvm qemu-kvm-0.12.1.2-2.355.0.1.el6.centos.7.x86_64 The problem is similar to this one: https://groups.google.com/forum/#!msg/mailing.freebsd.bugs/gw42Il1AX0o/3zj-gnRKgHIJ Two guests (tried both Fedora 19 and Ubuntu 12.04, without change) both with: - MACVTAP to eth0 - device model: virtio - source mode: bridge The guests can ping each other, but cannot ssh or access to any service each other.
Steps To Reproduce	- CentOS 6 host - 2 F19 guests - MACVTAP to eth0 - device model: virtio - source mode: bridge - test ping: OK - test ssh: fail
Additional Information	Important observations: - changing ONLY the device model in both guests to "Hypervisor default" which is "rtl8139" or other device models solves the problem: they can ssh each other; - having only one guest with "virtio" makes it impossibile to ssh the guest with "rtl8139" (although as usual they can ping each other); - (not 100% sure to remember correctly, but quite likely) using a Fedora 17 host presents the same problem (I think qemu-kvm-1.0.1-6.fc17.x86_64) - (100% sure) using a Fedora 19 host fixes the issue: virtio guests can ssh each other (qemu-kvm-1.4.2-7.fc19.x86_64). Let me know if you need any other test or information.
Tags	No tags attached.

tigalch 2013-09-13 12:46 manager ~0017996	I see the kernel is still at -358.6.2. Any specific reason you are not running -358.18.1? (most current kernel)

panda84 2013-09-13 12:50 reporter ~0017997	Yes, the host keeps up several guests so I don't reboot often. If there's any indication kernel-2.6.32-358.18.1.el6.x86_64 might fix this I'd be glad to try.

tigalch 2013-09-27 18:51 manager ~0018093	I didn't check the change log, but it is available here https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/6.4_Technical_Notes/kernel.html

panda84 2013-09-30 13:05 reporter ~0018109	Tried the latest kernel, but the problem is still present immutated: # uname -r 2.6.32-358.18.1.el6.x86_64 All the updates have been applied. It's easy to reproduce: install two guests using MACVTAP and use virtio on one of the two.

panda84 2013-10-25 11:21 reporter ~0018255	Same problem on a recent kernel, so it's probably not a kernel problem: # uname -r 3.11.4-1.el6.elrepo.x86_64

Date Modified	Username	Field	Change
2013-09-13 09:33	panda84	New Issue
2013-09-13 12:46	tigalch	Note Added: 0017996
2013-09-13 12:50	panda84	Note Added: 0017997
2013-09-27 18:51	tigalch	Note Added: 0018093
2013-09-30 13:05	panda84	Note Added: 0018109
2013-10-25 11:21	panda84	Note Added: 0018255