mplsTunnelARHopIpv6PrefixLen 1.3.6.1.4.1.11.2.3.7.11.12.2.15.15.3.2.7.1.7

If mplsTunnelARHopAddrType is set to ipV6(2), this value will contain the prefix length for this hop's IPv6 address. This object is otherwise insignificant and should contain a value of 0.