From: Haishuang Yan
Date: Sat, 21 May 2016 18:17:34 +0800
> When creat an ip6gretap interface with an unreachable route,
> the MTU is about 14 bytes larger than what was needed.
...
> Because rt is not NULL here, so dev->mtu will subtract the ethernet
> header length later. But when rt is NULL,
When creat an ip6gretap interface with an unreachable route,
the MTU is about 14 bytes larger than what was needed.
If the remote address is reachable:
ping6 2001:0:130::1 -c 2
PING 2001:0:130::1(2001:0:130::1) 56 data bytes
64 bytes from 2001:0:130::1: icmp_seq=1 ttl=64 time=1.46 ms
64 bytes from
