Re: [Xen-users] bonding + vlans ALMOST working, NO ARP

["Eli Criffield" <elicriffield@xxxxxxxxx>]

I opened a bug for this issue
http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=753

On 9/1/06, Eli Criffield <elicriffield@xxxxxxxxx> wrote:
> Nea all mac's are set static so the switchs and routers with arp cache
> don't have to update anything.
>
> Eli
>
> On 9/1/06, Tomasz Chmielewski <mangoo@xxxxxxxx> wrote:
> > Eli Criffield wrote:
> > > I'm very close to getting bonding + vlans + bridging to work.
> > >
> > > The only part that's not working is ARP.
> > >
> > > Why i have no idea? But if put in an arp entry for the default route
> > > manually with 'arp -s 192.168.129.1 00:00:0C:07:0C:C9' everything
> > > works great.  (Everything that goes though the default route anyway).
> > >
> > > Now if i run tcpdump on any of the interfaces involved in the bridge,
> > > eth0, eth1, bond0, vlan151 or vlan151-br, vif0,0, or veth0 (i don't
> > > rename any interfaces) then it works fine, I get arp replays. But if i
> > > use 'ip' to turn on promisc any of the interfaces it doesn't work,
> > > just like it doesn't work without promisc off.
> > >
> > > The script is a little diffrent then the last one i posted, I'll atach
> > > it at the end.
> > >
> > > Basically I'm combining eth0 and eth1 into bond0, add vlans to bond0
> > > named "vlanXXX"  make a bridge named vlanXXX-br and add vlanXXX to it,
> > > and then domU's are started with bridge=vlanXXX-br in there xen config
> > > file to decide what vlan they should be part of.
> > >
> > > So what is tcpdump doing to make arp work???
> >
> > Doesn't it look like this issue:
> >
> > 
> http://wiki.xensource.com/xenwiki/XenFaq#head-2e2a099d5575bb46de6d52786f093c13599af333
> >
> > 3.3. Why does my new domain receive no network traffic until after it
> > initiates an outgoing connection?
> >
> > This is an issue that occurs under the following circumstances:
> >
> >      * You do not specify the domain's MAC address, causing a random MAC
> > address to be selected at domain creation time
> >      * The upstream router has a local ARP cache
> >
> > When a domain is destroyed, the host system's ARP cache is purged of
> > addresses for the defunct virtual NIC. If the domain is recreated it is
> > likely to be allocated a different random MAC address. This is no
> > problem for the host machine, but the external switch/router still knows
> > the "old" MAC address. The switch/router requires an outbound packet to
> > the outside world to implicitly eradicate the old ARP-cache entry. This
> > is not really Xen's fault at all, just a property of the implementation
> > of ARP resolution.
> >
> >
> > --
> > Tomasz Chmielewski
> > http://wpkg.org
> >
_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users