Finn, I believe that is in fact what it is. I am just looking for a discussion or documentation on the architecture of this process. I sort of understand how it works but I'm not sure and am looking for an explanation. Thanks. Bill Wagman Univ. of California at Davis IET Campus Data Center wjwagman@xxxxxxxxxxx (530) 754-6208 ________________________________ From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Finn Jorgensen Sent: Thursday, February 21, 2008 5:28 PM To: William Wagman Cc: oracle-l@xxxxxxxxxxxxx Subject: Re: Question re IP address mapping in a RAC environment Wouldn't that be the VIP of node 2 that's migrated to node 1? Finn On Thu, Feb 21, 2008 at 5:38 PM, William Wagman <wjwagman@xxxxxxxxxxx> wrote: Greetings, Below is the output from ifconfig -a on one node of a two node RAC cluster running Oracle 10.2.0.3.0 EE on RHEL4. I just noticed something interesting today. If node 2 of the cluster is down there will appear an entry for eth0:2 with IP address for that node, see below. This makes sense to me, sort of, in that connections from node 2 must be redirected to node 2 and when node 2 comes back up the entry for eth0:2 no longer appears. My question, where can I find an explanation/documentation of what is occurring here and how it functions? I guess this is what the CRS is supposed to be doing, I'm just looking for more detail. Thanks. Both nodes up ---------- eth0 Link encap:Ethernet HWaddr 00:11:43:EB:C7:8C inet addr:128.120.45.32 <http://128.120.45.32/> Bcast:128.120.45.127 <http://128.120.45.127/> Mask:255.255.255.128 <http://255.255.255.128/> inet6 addr: fe80::211:43ff:feeb:c78c/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1157 errors:0 dropped:0 overruns:0 frame:0 TX packets:5437 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:122271 (119.4 KiB) TX bytes:619958 (605.4 KiB) Interrupt:233 eth0:1 Link encap:Ethernet HWaddr 00:11:43:EB:C7:8C inet addr:128.120.45.33 <http://128.120.45.33/> Bcast:128.120.45.127 <http://128.120.45.127/> Mask:255.255.255.128 <http://255.255.255.128/> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 Interrupt:233 eth1 Link encap:Ethernet HWaddr 00:11:43:EB:C7:8D inet addr:192.168.10.156 <http://192.168.10.156/> Bcast:192.168.10.255 <http://192.168.10.255/> Mask:255.255.255.0 <http://255.255.255.0/> inet6 addr: fe80::211:43ff:feeb:c78d/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:65825 errors:0 dropped:0 overruns:0 frame:0 TX packets:23028 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:70736721 (67.4 MiB) TX bytes:10977844 (10.4 MiB) Interrupt:50 Added when node 2 unavailable --------- eth0:2 Link encap:Ethernet HWaddr 00:0F:1F:69:6B:A1 inet addr:128.120.45.31 <http://128.120.45.31/> Bcast:128.120.45.127 <http://128.120.45.127/> Mask:255.255.255.128 <http://255.255.255.128/> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 Interrupt:233 Bill Wagman Univ. of California at Davis IET Campus Data Center wjwagman@xxxxxxxxxxx (530) 754-6208 -- //www.freelists.org/webpage/oracle-l