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Re: [webmin-l] Off-Topic arpwatch & Flip Flopping NICs
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From: Cary R. <ca...@to...> - 2006-06-22 17:03:03
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Thanks, Neal ! This is starting to feel like my lucky day :-$ At 11:36 AM 6/22/2006, you wrote: >I was just looking at something similar. From the Intel driver readme: > > > > >Multiple Interfaces on Same Ethernet Broadcast Network >------------------------------------------------------ >Due to the default ARP behavior on Linux, it is not possible to have one >system on two IP networks in the same Ethernet broadcast domain >(non-partitioned switch) behave as expected. All Ethernet interfaces >will respond to IP traffic for any IP address assigned to the system. >This results in unbalanced receive traffic. > >If you have multiple interfaces in a server, either turn on ARP >filtering by entering: > >echo 1 > /proc/sys/net/ipv4/conf/all/arp_filter >(this only works if your kernel's version is higher than 2.4.5), > >NOTE: This setting is not saved across reboots. The configuration change >can be made permanent by adding the line: >net.ipv4.conf.all.arp_filter = 1 >to the file /etc/sysctl.conf > >or, > >install the interfaces in separate broadcast domains (either in >different switches or in a switch partitioned to VLANs). > > > > > >-----Original Message----- >From: web...@li... >[mailto:web...@li...] On Behalf Of Cary >Robinson >Sent: Thursday, June 22, 2006 9:09 AM >To: web...@li... >Subject: [webmin-l] Off-Topic arpwatch & Flip Flopping NICs > >Sorry to trouble this list, but I have looked for days trying to find >info on my Flip Flopping NICs. > >I have 2 NICs, eth0 & eth1 and have assigned them the IP addresses >192.168.1.11 & 192.168.1.12 respectively. arpwatch reports that the >IP address 192.168.1.12 hops back & forth between the 2 NICs. > >Can anybody point me to a URL or book that can educate me on this >"Flip Flop" thing ? > > >Here are a few of the reports that arpwatch sends me via email. > > hostname: <unknown> > ip address: 192.168.1.12 > ethernet address: 0:c0:9f:b:96:ec > ethernet vendor: QUANTA COMPUTER, INC. >old ethernet address: 0:f:b5:fb:26:a9 > old ethernet vendor: <unknown> > timestamp: Wednesday, June 21, 2006 11:28:53 -0500 > previous timestamp: Wednesday, June 21, 2006 11:28:53 -0500 > delta: 0 seconds > > > > hostname: <unknown> > ip address: 192.168.1.12 > ethernet address: 0:f:b5:fb:26:a9 > ethernet vendor: <unknown> >old ethernet address: 0:c0:9f:b:96:ec > old ethernet vendor: QUANTA COMPUTER, INC. > timestamp: Wednesday, June 21, 2006 11:29:00 -0500 > previous timestamp: Wednesday, June 21, 2006 11:29:00 -0500 > delta: 0 seconds > > > > > hostname: <unknown> > ip address: 192.168.1.12 > ethernet address: 0:c0:9f:b:96:ec > ethernet vendor: QUANTA COMPUTER, INC. >old ethernet address: 0:f:b5:fb:26:a9 > old ethernet vendor: <unknown> > timestamp: Wednesday, June 21, 2006 11:29:01 -0500 > previous timestamp: Wednesday, June 21, 2006 11:29:00 -0500 > delta: 1 second > > >Thanks, >Cary Robinson > > > > >Using Tomcat but need to do more? Need to support web services, >security? >Get stuff done quickly with pre-integrated technology to make your job >easier >Download IBM WebSphere Application Server v.1.0.1 based on Apache >Geronimo >http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 >- >Forwarded by the Webmin mailing list at >web...@li... >To remove yourself from this list, go to >http://lists.sourceforge.net/lists/listinfo/webadmin-list > > >Using Tomcat but need to do more? Need to support web services, security? >Get stuff done quickly with pre-integrated technology to make your job easier >Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo >http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 >- >Forwarded by the Webmin mailing list at web...@li... >To remove yourself from this list, go to >http://lists.sourceforge.net/lists/listinfo/webadmin-list |