Thank's Altmark and Boyle for your answers :) I got about the same comment as yours Alan from our mainframe network people: That should not be a problem. And anyhow, our network dept now have a link to the right doc. Maybe they already know that , they just want to be sure :)
Cordialement / Vriendelijke Groeten / Best Regards / Med Vänliga Hälsningar Tore Agblad ________________________________________________ Tore Agblad System programmer, Volvo IT certified IT Architect Volvo Information Technology Infrastructure Mainframe Design & Development, Linux servers Dept 4253 DA1S SE-405 08, Gothenburg Sweden Telephone: +46-31-3233569 E-mail: [email protected] http://www.volvo.com/volvoit/global/en-gb/ ________________________________________ From: Linux on 390 Port [[email protected]] On Behalf Of Alan Altmark [[email protected]] Sent: Tuesday, May 15, 2012 17:48 To: [email protected] Subject: Re: Anybody know if VSWITCHes support 'spanning tree' , or need to do it ? On Tuesday, 05/15/2012 at 05:36 EDT, Agblad Tore <[email protected]> wrote: > We have that question from our network people, because we will need > to connect to a separate physical LAN for one customer, and we want the > migration > as seamless as possible. > So we will have duplicates of connections, of which both are redundant as well. > This will obviously expose us for the risk of network routing loops, and this is > prohibited with 'spanning tree' functionality, normally supported by switches > or routers. > > Any know if a z/VM vswitch support this or if it is perhaps not needed ? The VSWITCH does not support Spanning Tree Protocol. I have yet to hear of anyone actually having a problem with broadcast storms on their zLinux guests. When a Linux guest broadcasts, that broadcast will go out on the wire, but will not be reflected back on the same port (IEEE standard). If it comes into another VSWITCH plugged into another port in the same VLAN, then it will be to a different interface on the Linux guest. Linux will not forward a broadcast or multicast packet, as other interfaces on the same subnet will have heard the bcast/mcast, and it is not permitted to forward them to other subnets. (Even subnet-directed broadcasts will not be forwarded.) When it comes to networking, Linux is pretty well-behaved. Alan Altmark Senior Managing z/VM and Linux Consultant IBM System Lab Services and Training ibm.com/systems/services/labservices office: 607.429.3323 mobile; 607.321.7556 [email protected] IBM Endicott ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/ ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
