XFAC (?)

[Laurent Archambault]

Hello all,

After many search, i has not find my answer, whay do it mean the status
"XFAC" (?).
I has find this "Extra Fast Attack Crafts", and i am very happy for
this...but in french language it's
very difficult to understand this status "XFAC".
Many thanks - best regards

[David J Taylor]

Post by Laurent Archambault
Hello all,
After many search, i has not find my answer, whay do it mean the status
"XFAC" (?).
I has find this "Extra Fast Attack Crafts", and i am very happy for
this...but in french language it's
very difficult to understand this status "XFAC".
Many thanks - best regards

Is this in relation to NTP? One use I found was the string ".XFAC." used
as reference clock source ID (I think).

In other use, you might have scaling for a graph of x-factor and y-factor,
so XFAC and YFAC.

Cheers,
David

[Uwe Klein]

Post by David J Taylor

Post by Laurent Archambault
After many search, i has not find my answer, whay do it mean the status
"XFAC" (?).

Is this in relation to NTP? One use I found was the string ".XFAC."
used as reference clock source ID (I think).

Looks like, why else would laurent ask here?

Post by David J Taylor
In other use, you might have scaling for a graph of x-factor and
y-factor, so XFAC and YFAC.

Hmpf.

Post by David J Taylor
Cheers,
David

grep -A1 -B2 XFAC $(find . -type f)

./ntp-4.2.6p2-RC3/ntpd/ntp_peer.c- if (peer->dstadr != piface && !(peer->cast_flags &
./ntp-4.2.6p2-RC3/ntpd/ntp_peer.c- MDF_ACAST) && peer->pmode != MODE_BROADCAST)
./ntp-4.2.6p2-RC3/ntpd/ntp_peer.c: peer_clear(peer, "XFAC");
./ntp-4.2.6p2-RC3/ntpd/ntp_peer.c-
--
./ntp-4.2.6p2-RC3/CommitLog- use (peer->pmode == MODE_BROADCAST) rather than
./ntp-4.2.6p2-RC3/CommitLog- (peer->castflags & MDF_BCLNT) to detect ephemeral broadcastclient
./ntp-4.2.6p2-RC3/CommitLog: associations to exempt from peer_clear("XFAC")
./ntp-4.2.6p2-RC3/CommitLog-
--
./ntp-4.2.6p2-RC3/CommitLog- use (peer->pmode == MODE_BROADCAST) rather than
./ntp-4.2.6p2-RC3/CommitLog- (peer->castflags & MDF_BCLNT) to detect broadcastclient
./ntp-4.2.6p2-RC3/CommitLog: associations to exempt from peer_clear("XFAC"), suggested
./ntp-4.2.6p2-RC3/CommitLog- by Frank Kardel.
--
./ntp-4.2.6p2-RC3/CommitLog-
./ntp-4.2.6p2-RC3/CommitLog- ntpd/***@1.122, 2009-10-15 03:30:55+00:00,
***@shiny.ad.hartbrothers.com +1 -1
./ntp-4.2.6p2-RC3/CommitLog: Do not peer_clear("XFAC") manycast server associations or they will
./ntp-4.2.6p2-RC3/CommitLog- never regain their ACST refid.

now what kind of peer would be tagged "XFAC" ??

inquisitive minds want to know ;-)

uwe

[Miroslav Lichvar]

Post by Uwe Klein

Post by Laurent Archambault
After many search, i has not find my answer, whay do it mean the status
"XFAC" (?).

grep -A1 -B2 XFAC $(find . -type f)
ntp_peer.c- if (peer->dstadr != piface && !(peer->cast_flags &
ntp_peer.c- MDF_ACAST) && peer->pmode != MODE_BROADCAST)
ntp_peer.c: peer_clear(peer, "XFAC");
ntp_peer.c-
now what kind of peer would be tagged "XFAC" ??
inquisitive minds want to know ;-)

There is a comment before that hunk:

/*
* clear crypto if we change the local address
*/

So it would seem the string is used when the network interface which is
used to send packets to the peer has changed its address and the crypto
stuff had to be reset.

[Dave Hart]

Post by Laurent Archambault
After many search, i has not find my answer, whay do it mean the status
"XFAC" (?).

ntpd resets associations when the local network interface (or, really,
IP address) being used for that peer goes away. This means the clock
filter register of 8 samples is cleared, as are all other timekeeping
stats related to the peer. At that time, the "reference ID" or refid
is changed to XFAC to indicate the cause of the cleared (reset)
association. Typically, that XFAC refid is replaced on receipt of the
next packet from the server or peer.

Since you ask what it means without telling us what problem you are
having, I'm left supposing you are asking because it is not
short-lived in your case. You may be able to work around the problem
by adding -U0 to the ntpd command line so that local network
interfaces (IP addresses) are enumerated by ntpd only once at startup.

Cheers,
Dave Hart

[Uwe Klein]

Post by Dave Hart

Post by Laurent Archambault
After many search, i has not find my answer, whay do it mean the status
"XFAC" (?).

ntpd resets associations when the local network interface (or, really,
IP address) being used for that peer goes away. This means the clock
filter register of 8 samples is cleared, as are all other timekeeping
stats related to the peer. At that time, the "reference ID" or refid
is changed to XFAC to indicate the cause of the cleared (reset)
association. Typically, that XFAC refid is replaced on receipt of the
next packet from the server or peer.
Since you ask what it means without telling us what problem you are
having, I'm left supposing you are asking because it is not
short-lived in your case. You may be able to work around the problem
by adding -U0 to the ntpd command line so that local network
interfaces (IP addresses) are enumerated by ntpd only once at startup.
Cheers,
Dave Hart

Hi Dave,

so XFAC stands for
X Inter
F Face
A Association
c Change
??

Does this only happen on interface down/change or at ntp bootup too ?

uwe

[Dave Hart]

Post by Uwe Klein
so XFAC stands for
X Inter
F Face
A Association
c Change
??

I really don't know what was imagined initially. Perhaps eXchange
interFACe? With four capital letters used for these locally-generated
pseudo-refids, there's not a lot of room for clarity.

Post by Uwe Klein
Does this only happen on interface down/change or at ntp bootup too ?

Only on interface change. At startup, each association shows .INIT.
as the refid.

Cheers,
Dave Hart

[Uwe Klein]

Post by Dave Hart

Post by Uwe Klein
so XFAC stands for
X Inter
F Face
A Association
c Change
??

I really don't know what was imagined initially. Perhaps eXchange
interFACe? With four capital letters used for these locally-generated
pseudo-refids, there's not a lot of room for clarity.

Post by Uwe Klein
Does this only happen on interface down/change or at ntp bootup too ?

Only on interface change. At startup, each association shows .INIT.
as the refid.
Cheers,
Dave Hart

Thank you.

uwe