After some research, I was wondering if it was possible to define a TTL by interface as I can the Hop Limit definition in ipv6.To change the TTL in IPv4, I can change the file /proc/sys/net/ipv4/ip_default_ttl But this changes TTL for all interfaces.However in IPv6, you can put a different hop limit value for each interfaces   /proc/sys/net/ipv6/conf/eth*/hop_limitSo do I miss something? or there is no way to configure a different TTL for each interface ?
Define specific TTL for each interfaces
ipv6;interface;ipv4
If that entry does not exist for ipv4, it's probably not supported.But have you tried to modify TTL values with iptables? See if the TTL target helps