I think what is wanted may be something like: eth0 goes to LAN-A (10.170.0.0/16) while eth1 to to LAN-B (10.171.0.0/16). But both LANs have their own separate gateway which connects to the world-wide Internet. So the customer wants be be able to use either eth0 or eth1 when the destination is on the Internet. He does not want all Internet traffic to go through only the last eth? which was activated. I don't think you can have a single IP address routed randomly through whichever eth? happens to be available. I.e. www.redhat.com is accessable via LAN-A or LAN-B, so the user wants the server to pick whichever one is not busy and use it. I don't think this is possible.
-- John McKown Systems Engineer IV IT Administrative Services Group HealthMarkets(r) 9151 Boulevard 26 * N. Richland Hills * TX 76010 (817) 255-3225 phone * [email protected] * www.HealthMarkets.com Confidentiality Notice: This e-mail message may contain confidential or proprietary information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. HealthMarkets(r) is the brand name for products underwritten and issued by the insurance subsidiaries of HealthMarkets, Inc. -The Chesapeake Life Insurance Company(r), Mid-West National Life Insurance Company of TennesseeSM and The MEGA Life and Health Insurance Company.SM > -----Original Message----- > From: Linux on 390 Port [mailto:[email protected]] On > Behalf Of Christian Paro > Sent: Thursday, March 03, 2011 2:01 PM > To: [email protected] > Subject: Re: Using 2 NIC addresses to different networks on > different VSWITCHes > > A system can only have one default interface. But it should > only be falling > back to default when one of the more specific routes have not > been met. > > So if I have a system like this: > > # route > Kernel IP routing table > Destination Gateway Genmask Flags Metric Ref Use Iface > 9.1.2.3 * 255.255.255.128 U 0 0 0 eth0 > 10.1.0.0 * 255.255.0.0 U 0 0 0 eth1 > link-local * 255.255.0.0 U 0 0 0 eth0 > loopback * 255.0.0.0 U 0 0 0 lo > default * 0.0.0.0 U 0 0 0 eth0 > > ...anything going to 10.1.x.x is going through eth1, anything > going through > 9.1.2.0-9.1.2.128 is going through eth0, anything that doesn't fall to > either of those (or link-local or loopback) goes through the default > interface (eth0) using the gateway associated with that > interface (9.1.2.1) > on the assumption that said gateway will be able to route > this traffic on > toward its destination subnet. > > That config is working mostly off of assumptions based on > each interface's > ifcfg* file, with the only explicit routing configuration being this: > > # cat /etc/sysconfig/network/routes > default - - eth0 > > ...if something more advanced than this kind of assumption > (forward traffic > for the subnet an interface is on to that interface, > everything that doesn't > match one of those subnets through the gateway associated > with the "default" > interface) is needed, that can also be configured in > /etc/sysconfig/network/routes on SLES. RHEL has separate per-interface > routing files under /etc/sysconfig/network-scripts, if I > remember correctly. > > If, for instance, I wanted to forward traffic outbound to > 10.2.x.x through > eth1 using the 10.1.0.1 gateway instead of eth0 using the > 9.1.2.1 gateway, > I'd need to create another routing line for that. > > That would look something like: > > # cat /etc/sysconfig/network/routes > 10.2.0.0 10.1.0.1 255.255.0.0 eth1 > default - - eth0 > > On Thu, Mar 3, 2011 at 2:52 PM, Pat Carroll > <[email protected]> wrote: > > > Mike, > > Has the customer tried to put the appropriate GATEWAY= > statement in each > > ifcfg_ethx? > > PC > > > > > > Patrick Carroll | Technology Architect II > > L.L.Bean, Inc.(r) | Double L St. | Freeport ME 04033 > > http://www.llbean.com | [email protected] | 207.552.2426 > > > > CONFIDENTIALITY NOTICE: This e-mail and any attachments may contain > > confidential information that is legally privileged. The > information is > > solely for the use of the intended recipient(s). Any > disclosure, copying, > > distribution, or other use of this information is strictly > prohibited. If > > you have received this e-mail in error, please notify the > sender by return > > e-mail and delete this message. > > > > > > -----Original Message----- > > From: Linux on 390 Port [mailto:[email protected]] On > Behalf Of > > Michael MacIsaac > > Sent: Thursday, March 03, 2011 2:36 PM > > To: [email protected] > > Subject: Using 2 NIC addresses to different networks on > different VSWITCHes > > > > I'm asking this question on the behalf of a customer: > > I have this set up fine as far as VM is concerned, and have > eth0 and eth1 > > defined on Linux (RHEL 5.5). > > My problem is that the networks defined by eth0 and eth1 > have different > > gateway addresses, but when both interfaces are brought up, > the default > > gateway becomes the gateway of the last interface started. > This renders the > > previous interfaces unusable. > > How do I configure a different gateway for each interface > successfully? > > Thanks for any help or ideas you might give me, > > > > "Mike MacIsaac" <[email protected]> (845) 433-7061 > > > > > ---------------------------------------------------------------------- > > For LINUX-390 subscribe / signoff / archive access > instructions, send email > > to [email protected] with the message: INFO LINUX-390 or visit > > http://www.marist.edu/htbin/wlvindex?LINUX-390 > > > ---------------------------------------------------------------------- > > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > > > > > ---------------------------------------------------------------------- > > For LINUX-390 subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: INFO > LINUX-390 or > > visit > > http://www.marist.edu/htbin/wlvindex?LINUX-390 > > > ---------------------------------------------------------------------- > > For more information on Linux on System z, visit > > http://wiki.linuxvm.org/ > > > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO > LINUX-390 or visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
