I'm not positive, but I think I am correct in believing you can work
around this with the rp_filter (reverse path filter) setting via sysctl or
the /proc filesystem. See TID# 7007649
(https://www.suse.com/support/kb/doc?id=7007649) or RFC 3704
(https://www.ietf.org/rfc/rfc3704.txt) for more information.

Good luck.

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