Shared dynamic zone on external view?

[Nicolas C.]

Hello,

I have a dynamic zone on an external view, this zone is updated with a 
TSIG key from outside of our network. There is a secondary DNS server, 
also outside our network on which zones transfers are working fine with 
no key.

We would like to make one of our internal DNS secondary for this zone 
and we have the "dynamic zone shared between views" problem. I tried to 
follow the FAQ but no luck so far.

I'm not sure that what I'm trying to do is possible, can someone confirm 
this?

Should I follow the FAQ and make my dynamic zone "master" on the 
"internal" view? That makes less sense to us because this are public 
zones, updated from the outsite.

This is my configuration :

view "internal" {
   match-clients {

     !key external;
     key shared;

     <IPv4/IPv6 ranges including IPv4-of-my-DNS>
   };

   zone "<my_zone>" {
     type slave;
     file "db.shared-int";
     masters { IPv4-of-my-DNS; };
     transfer-source IPv4-of-my-DNS;
   };
};

view "external" {

   match-clients { !key shared; any };
   allow-transfer { IPv4-of-my-DNS; };
   server IPv4-of-my-DNS; { keys { shared; }; };

   zone "<my_zone>" {
     type master;
     file "db.shared-ext";
     notify yes;
     also-notify { IPv4-of-my-DNS; };

     update-policy {
       grant another-key subdomain <my_zone> ANY;
       grant principal at REA.LM subdomain <my_zone> ANY;
     };
};

When I reload the configuration or try to initiate a zone transfer with 
dig and the "shared" key, I have this message in the logs.

zone <my_zone>/IN/internal: refresh: unexpected rcode (SERVFAIL) from 
master IPv4-of-my-DNS#53 (source IPv4-of-my-DNS#0)

Regards,

Nicolas