Messages in this thread | | | Date | Sat, 12 Aug 2006 19:22:02 +0200 (MEST) | From | Jan Engelhardt <> | Subject | Re: Q: remapping IP addresses for inbound and outbound traffic |
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>Let one Linux box have two interfaces to IPv4 networks, >and for some IP both networks have the host with this IP address, e.g. from RFC1918. >Or even both use the same IPv4 address block. >We can say that one IP from the first network >and numerically the same IP from the second "means" different hosts. > >I clarify these terms so carefully because in news:comp.os.linux.networking >some people state that I "use terms in strange ways" :)
But we are not in comp.os.linux.networking here, and getting a concrete example like "my eth0 has 134.76.13.21/24 and my eth1 has 10.foo.bar/xyz" is a little easier to understand.
>The software of this box needs to connect all hosts in both networks, >and also to receive inbound TCP connections. >The evident way is to "remap" overlapping IPv4 area of one network >to some "place" not used neither in it nor in other.
If they do not use the same address block, they don't overlap and there is no need to remap them.
>This means that, when we receive a packet from remapped area, >the kernel should replace the source IP to an "internal representaion". >Versa, sending something to "internally represented" IP >the kernel should replace such IP by its external value.
Jan Engelhardt -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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