From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.9) Gecko/20020313 Description of problem: /proc/sys/net/ipv4/conf/eth0/rp_filter controls the (poorly documented) reverse path filter feature for eth0. The user can control this through /etc/sysctl.conf, but sysctl(8) is only run automatically at boot time. Since interfaces are brought up at other times, the right control would be a new variable within /etc/sysctl/network-scripts/ifcfg-*. ifup should implement this. Version-Release number of selected component (if applicable): initscripts-6.67-1 How reproducible: Always Steps to Reproduce: On a notebook with eth0 on a PCMCIA card On a notebook where eth0 is a PCMCIA card: 1.in /etc/sysctl.conf, place "net.ipv4.conf.eth0.rp_filter = 0" but leave net.ipv4.conf.default.rp_filter = 1 2.reboot machine 3.insert eth0 4.examine /proc/sys/net/ipv4/conf/eth0/rp_filter. It will be 1 but should be 0. Actual Results: /proc/sys/net/ipv4/conf/eth0/rp_filter is 1 Expected Results: /proc/sys/net/ipv4/conf/eth0/rp_filter is 0 Additional info: rp_filter should be better documented. It does not seem to be mentioned in the man pages. It is described in the kernel source files: Documentation/filesystems/proc.txt Documentation/networking/ip-sysctl.txt
Closing bugs on older, no longer supported, releases. Apologies for any lack of response. Realistically, the best way to support this is probably via a udev rule on device creation in current releases.