On Friday, 02/22/2008 at 11:18 EST, "Huegel, Thomas" <[EMAIL PROTECTED]> wrote: > I have something that seems very odd to me. > > I have this z/LINUX machine that is on a vswitch and has an IP address of > 1x2.xx.x.192. > > One time when I do a NETSTAT ARP I get this: > Link ETH0 : QDIOETHERNET: 020041000101 IP: 1x2.xx.x.192 > > The next time I do it I get this: > Link ETH0 : QDIOETHERNET: 00096B1A8CF8 IP: 1x2.xx.x.192 > > How can the MAC address change? > The first one appears to be virtual (I don't know where it comes from) the > second appears to be a real OSA.. > > Or is this normal?
One thing to know about NETSTAT ARP is that it works like this for layer 3 OSA: 1. Display the shadow ARP cache 2. Request an asnyc update of the shadow ARP cache So if you haven't issued the NETSTAT ARP command in a "long" time and there has been a "takeover" on the MAC or a change from Layer 2 to layer 3 within the same host, then I would expect to see the results you saw due to stale data in the shadow cache. Go to the system you think is 1x2.xx.x.192 and see if its MAC address matches what you are seeing. Oh, and that "takeover" I mentioned? That might not be intentional, if you get my drift. Alan Altmark z/VM Development IBM Endicott
