Networking – What is the IP Address 169.254.169.254?

I've had success with Sysinternals Process Explorer. With this, you can search to find what process(es) have a file open, and you can use it to close the handle(s) if you want. Of course, it is safer to close the whole process. Exercise caution and judgement.

To find a specific file, use the menu option Find->Find Handle or DLL... Type in part of the path to the file. The list of processes will appear below.

If you prefer command line, Sysinternals suite includes command line tool Handle, that lists open handles.

Examples

• c:\Program Files\SysinternalsSuite>handle.exe |findstr /i "e:\" (finds all files opened from drive e:\"
• c:\Program Files\SysinternalsSuite>handle.exe |findstr /i "file-or-path-in-question"

By default, on Linux, if an interface has multiple addresses that are on different subnets, traffic destined for the respective subnets will have the proper source IP. That is, if eth0 has two addresses 192.168.1.1/24 and 10.1.1.1/8, then traffic to anything on the 10.0.0.0 subnet will have source 10.1.1.1, and traffic to anything on the 192.168.1.0 subnet will have source 192.168.1.1. You can also assign source addresses explicitly in this case by using the "src 1.2.3.4" option to "ip route".

In your case, though, all your addresses are on the same subnet, so the "primary" one (as revealed by "ip addr list dev eth0") is used as the source IP for traffic exiting on that interface. I think it's possible to control the source IPs in this case just using "ip route", but I've found it easier to use iptables to rewrite the source addresses for traffic of interest.

If you want to force a specific source address to be used for specific destinations, you can do it with a SNAT rule:

iptables -t nat -I POSTROUTING -o eth0 -d dest-IP-or-net/mask -s primary-IP-of-eth0 -j SNAT --to-source desired-source-IP

So if your "primary" eth0 IP is 192.168.100.1, but you want traffic to 1.2.3.4 to have a source of 192.168.100.2, then do this:

iptables -t nat -I POSTROUTING -o eth0 -d 1.2.3.4/0 -s 192.168.100.1 -j SNAT --to-source 192.168.100.2

Note that the "-s 192.168.100.1" is important: it prevents forwarded traffic's source addresses being rewritten by this rule.

If you are going to implement complex network configurations on Linux, you should read the Linux Advanced Routing and Traffic Control documentation, http://lartc.org