It's not so much hard as it is knowing all the hops in your network. If anything along the chain has a low MTU, the whole route is effectively reduced. On 21/11/13 20:20, Nico Kadel-Garcia wrote: > This is int4eresting stuff. I do note that the "virt-manager" tool, > and NetworkManager, give *no* insight and detailed management > sufficient to resolve this stuff. Note also that dancing through all > the hoops to get this working, end-to-end, is one of the big reasons > that most environments refuse to even *try* to use jumbo frames, as > helpful as they sometimes are to heavy data transfers. > > On Thu, Nov 21, 2013 at 6:58 PM, Digimer <lists at alteeve.ca> wrote: >> On 21/11/13 18:20, aurfalien wrote: >>> >>> On Nov 21, 2013, at 2:45 PM, Digimer wrote: >>> >>>> The 'vnetX' number doesn't relate to the interface, bridge or anything >>>> else. The vnetX number is a simple sequence that increments each time a >>>> VM is started. So don't think that you need 'vnet6'... it can be anything. >>>> >>>> The 'brctl show' output from earlier showed that both vnet0 and vnet1 >>>> were connected to br0. You can try using the bridge utils to remove them >>>> from br0 and connect them to br6 as a test. >>>> >>>> -- >>>> Digimer >>> >>> Well, when I remove vnet1 from br0 and add vnet1 to br1, I loose connectivity with my VMs. >>> >>> No biggy so I reboot my entire host. >>> >>> Then vnet1 show back under br0. >>> >>> I just don't understand enough about this to get a clue, depressing. >>> >>> - aurf >> >> Think of each bridge as if it were a physical switch. >> >> When you detached vnet1 from br0, you unplugged it from a switch. When >> you attached it to br1, you plugged it into another switch. >> >> If there is no connection out to your network/internet on a given >> switch, then anything plugged into that switch will go nowhere. Same >> with bridges. >> >> You seemed to indicate earlier that the main connection was on br6. Is >> this true? If so, then "switch" br6 is the switch with the "uplink" to >> your network. Plug a VM into it and you can route out through it. >> >> When you rebooted the VM, the hypervisor read the definition file. That >> definition file says to plug in the server to br0. So it makes sense >> that the reboot reconnected it to br0. >> >> If you want to use jumbo frames on the br0 switch, you need to set the >> larger MTU on the interfaces are all set to your desired MTU size. >> >> -- >> Digimer >> Papers and Projects: https://alteeve.ca/w/ >> What if the cure for cancer is trapped in the mind of a person without >> access to education? >> _______________________________________________ >> CentOS-virt mailing list >> CentOS-virt at centos.org >> http://lists.centos.org/mailman/listinfo/centos-virt > _______________________________________________ > CentOS-virt mailing list > CentOS-virt at centos.org > http://lists.centos.org/mailman/listinfo/centos-virt > -- Digimer Papers and Projects: https://alteeve.ca/w/ What if the cure for cancer is trapped in the mind of a person without access to education?