Linux Solutions

Welcome to the tutorial guide. The guide will provide a user with guidance and instructions on ipv4 per device settings.

Please note that DEV can either stand for a real interface, or for ‘all’ or ‘default’. Default also changes settings for interfaces.
/proc/sys/net/ipv4/conf/DEV/accept_redirects
If a router decides that a user is using it for a wrong purpose (i.e., it needs to resend the users packet on the same interface), it will send us a ICMP Redirect. As this is a security risk so it is worth to turn it off, or use secure redirects.
/proc/sys/net/ipv4/conf/DEV/accept_source_route
This is not used that much and if a user used to be able to give a packet a list of IP addresses it should visit on its way. Linux can be made to honor this IP option.
/proc/sys/net/ipv4/conf/DEV/bootp_relay
Accept packets with source address 0.b.c.d with destinations not to this host as local ones. It is supposed that a BOOTP relay daemon will catch and forward such packets.
The default is 0, since this feature is not implemented yet (kernel version 2.2.12).
/proc/sys/net/ipv4/conf/DEV/forwarding
Enable or disable IP forwarding on this interface.

/proc/sys/net/ipv4/conf/DEV/mc_forwarding
If a user wants to do multicast forwarding on this interface
/proc/sys/net/ipv4/conf/DEV/proxy_arp
If a user sets this to 1, this interface will respond to ARP requests for addresses the kernel has routes to. It is useful if a user wants to build ip pseudo bridges. A user should be aware that the the netmasks are very correct before enabling this. Also the user should be aware that the rp_filter, operates on ARP queries!
/proc/sys/net/ipv4/conf/DEV/secure_redirects
Accept ICMP redirect messages only for gateways, listed in default gateway list. Enabled by default.
/proc/sys/net/ipv4/conf/DEV/send_redirects
If a user sends the above mentioned redirects.
/proc/sys/net/ipv4/conf/DEV/shared_media
If it is not set the kernel does not assume that different subnets on this device can communicate directly. Default setting is ‘yes’.
/proc/sys/net/ipv4/conf/DEV/tag

If you followed advise and guidance as provided in this tutorial guide then you would have learnt about ipv4 per device settings.