I configured an ipipv6 tunnel between two MT devices, all with v6.46.4. When checking ipv6 firewall connections, I found a protocol=ipv6-encap connection, just like this:

[admin@MT] > ipv fi co pri de
Flags: S - seen reply, A - assured
0 S protocol=ipv6-encap src-address=2409:8a20:abcd:ef00::1 dst-address=240e:3a1:1234:5678::1 reply-src-address=240e:3a1:1234:5678::1
reply-dst-address=2409:8a20:abcd:ef00::1 timeout=9m54s

While there was no traffic in this tunnel, the "timeout" value of this connection refreshed to 9m59s every 10s.
But why protocol 41 (ipv6-encap) ? shouldn't it be protocol 4 (ipencap)? Just like the normal data carrying connection:

Flags: S - seen reply, A - assured
4 S protocol=ipencap src-address=2409:8a20:abcd:ef00::1 dst-address=240e:3a1:1234:5678::1 reply-src-address=240e:3a1:1234:5678::1
reply-dst-address=2409:8a20:abcd:ef00::1 timeout=9m58s

Another problem is , when ipv6 address of device changes for pppoe redialing, the local address of ipipv6 tunnel has no change, and tunnel is down actually.
I didn't configure "local-address" value. I think it should be changed automatically.

[admin@MT] > int ipipv6 pri de
Flags: X - disabled, R - running
0 name="v6tun" mtu=auto actual-mtu=1440 local-address=:: remote-address=xxxxxxxxxxx.sn.mynetname.net
current-remote-address=240e:3a1:1234:5678::1 keepalive=10s,10 dscp=inherit clamp-tcp-mss=yes

Does anyone have any opinions ?

update:

First problem, I change it with option "unset keepalive", there is no ipv6encap connection anymore, but I think it's a bug anyway.

Second problem, when ipv6 address of device changes for pppoe redialing, the local address of ipipv6 tunnel has no change, and tunnel is down actually. While showing ipv6 firewall connection, Local address still remains old value actually.Please fix it!