Viktor Dukhovni:
> On Sun, Aug 16, 2020 at 11:24:31AM -0700, Greg Sims wrote:
>
> > This date contradicts some recommendations on the Internet of turning
> > off the Connection Cache when randmap is used to "increase
> > randomness".
>
> The connection cache has zero impact on transport selection, connections
> are *never* reused across transports. The transport name is part of the
> connection cache lookup key. All sorts of people, who half-know what
> they're talking about, write HOWTO documents explaining how to do some
> task in a half-arsed way. :-(
Confirmed. The master.cf service name (i.e. transport name) is
an unconditional part of the connection cache lookup key.
For cache lookup by destination name:
#define SMTP_KEY_MASK_SCACHE_DEST_LABEL \
(SMTP_KEY_FLAG_SERVICE | COND_SASL_SMTP_KEY_FLAG_SENDER \
| SMTP_KEY_FLAG_REQ_NEXTHOP)
For cache lookup by server IP address:
#define SMTP_KEY_MASK_SCACHE_ENDP_LABEL \
(SMTP_KEY_FLAG_SERVICE | COND_SASL_SMTP_KEY_FLAG_SENDER \
| COND_SASL_SMTP_KEY_FLAG_CUR_NEXTHOP \
| COND_SASL_SMTP_KEY_FLAG_HOSTNAME \
| COND_TLS_SMTP_KEY_FLAG_CUR_NEXTHOP | SMTP_KEY_FLAG_ADDR | \
SMTP_KEY_FLAG_PORT | SMTP_KEY_FLAG_TLS_LEVEL)
So yeah, some information on the Internet is incorrect.
Wietse
