On Wed, Mar 9, 2011 at 6:38 AM, Doug Hughes <[email protected]> wrote: > I did a google search and saw a few things about LAPs and trunk vs > access ports. I don't know if you've seen > this one: https://learningnetwork.cisco.com/thread/7715
I didn't test putting the physical host on a trunk port with a native vlan. (The whole setup is a twelve-hour plane ride away so I need to be a bit careful with it.) > can the machine that is acting as the vm container for hostA reach other > machines or does it also have the same > intra-vlan restrictions (trying to eliminate your VM stuff as a > problem). You could try to turn on port mirroring > on the switch and put tshark or equivalent on there and see what packets > are actually going on that vlan. The VM's management interface is on a different physical interface and has no trouble connecting to any of the hosts. Initially I suspected the VM host, but I've pretty much ruled it out. When HostA (physical) tries to ping the VM I see the ARP requests on the router's interface but not on the virtual interface on the VM host. So the physical port works and ARP is traversing the switch from that port. When HostB (vm) tries to ping the physical host I see the ARP requests on the router's interface but not on the interface of the physical host. So the virtual port works and ARP is traversing the switch from that port. And once the hosts are in each other's ARP tables communication between hosts is perfect. So the network ports on the hosts must be working and the switch ports configured correctly. On the other hand, the router is also on a trunk port and that port seems to be behaving as expected; and on the other other hand I have the same kind of setup at another site where the switch doesn't do VLAN routing and it doesn't have this problem. I'm hoping there is some obscure feature of the Cisco switch that is causing the problem. But it's not proxy-arp or dynamic arp inspection. (I'm no Cisco guru so I'm even clear on what I should be looking for.) > On 3/8/2011 11:11 PM, Atom Powers wrote: >> I haven't seen this before and it's causing me all kinds of headache. >> >> HostA can NOT ping HostB (or other VMs on that network) and HostB can >> NOT ping HostA (or other physical servers on that network). >> >> I can see ARP requests on RTR from both HostA and HostB, but the hosts >> themselves never see the ARP requests from the other host. >> >> If I manually add the hosts to each other's ARP table then HostA can >> ping HostB and visa versa. >> >> So ... What the heck is going on? Why isn't the switch forwarding the >> ARP requests to all ports on the same VLAN? >> -- Perfection is just a word I use occasionally with mustard. --Atom Powers-- _______________________________________________ Tech mailing list [email protected] https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
