> do you mean making apache use a specific IP when it proxies the request? > (you really lost me, so I may be misunderstanding). why do need that at > all? whatever IP is used should not matter since the backend will reply > over the socket that was opened by the proxy (be it a production proxy > or the test proxy). > Both IP addresses are actually assigned to the same physical interface (eth1 and eth1:1). The proxy instance is accepting connections from clients using the eth1:1 secondary interface, but the same PHYSICAL interface as eth1. When it turns around and connects to the back-end service, it seems to be using eth1 even though it's listening on eth1:1. Since it's not listening to eth1, the packets are going to the bit-bucket. At least that's my theory. > otherwise, the IP is selected by the kernel depending on the > destination. so if you use something like > ProxyPass / http://10.1.2.3:8080/ > in one proxy and > ProxyPass / http://10.4.5.6:8080/ > > each will use the "selected" IP. > >> Is there something I can do with routing tables that can help? >> > That would require "advanced" routing. standard routing is based on > destination and the source IP is selected by the kernel after the route > has been computed (this allows setting the right IP should you have > multiple network interfaces...). > > but you should not need this. In the end, I may just have to either use a separate server or a second physical interface, probably in another VLAN, to make this work. And my idea seemed like such a good one. === Al