Hi,
Between about 20:25Z and ~20:50Z today host "Jack" lost all
networking. All of the VMs on it became unreachable.
It seems to have been some sort of kernel driver bug in the
Ethernet module as it was "stuck" not passing traffic but the
interface still showed as up.
The hosts have bonded network interfaces to protect against switch
failure, but as the interface stayed up this was not considered
failed. Also they are in active-backup mode and the currently-active
interface was the one that was stuck, so all traffic was trying to
go that way.
Networking was restored by setting the link down and up again.
Traffic started to flow again, BGP sessions re-established and all
was fine again.
We could look into some sort of link keepalive method on the bonded
interfaces as opposed to just relying on link state, but we have
already decided to move away from bonded networking in favour of
separate BGP sessions on each interface, That is how the next new
servers will be deployed; they will not have network bonding. We
have not yet tackled moving existing servers to this setup.
If we had been in the situation without bonding I think we would
have fared better here: there would have been a short blip while one
BGP session went down, but the other would remain and we'd be left
with some alerting and me scratching my head wondering why an
interface that is up doesn't pass traffic.
I will do some more investigation of this failure mode but in light
of doing away with bonding being the direction we are already going,
I don't think I want to alter how bonding is done on what will soon
be a legacy setup.
Thanks,
Andy
--
https://bitfolk.com/ -- No-nonsense VPS hosting
Hi folks
I'm running mail-in-a-box on a Bitfolk VPS.
https://mailinabox.email/
It's making the following complaint:
"This box's reverse DNS is currently aquitaine.richardskingdom.net
(IPv4) and 2001-ba8-1f1-f037-0-0-0-2.autov6rev.bitfolk.space (IPv6), but
it should be aquitaine.richardskingdom.net. Your ISP or cloud provider
will have instructions on setting up reverse DNS for this box."
This is with reverse DNS set to "automatic" in the Bitfolk panel.
The only other panel option seems to be to delegate the reverse IPv6
zones to my name server.
I'm using the mail-in-a-box built-in name server, however, and
delegating to that produces the following result:
"This box's reverse DNS is currently aquitaine.richardskingdom.net
(IPv4) and [Not Set] (IPv6), but it should be
aquitaine.richardskingdom.net ..."
I infer that mail-in-a-box name server is not setting reverse IPv6
records for itself.
There doesn't appear to be a way to tell mail-in-a-box to set the
reverse DNS correctly via its GUI - there is no option to add a custom
PTR record (other record types can be added).
I don't know what name server software is running under the hood, and
I'm loath to make config changes except via the GUI in case they get
overwritten when mail-in-a-box updates.
Can anyone advise me how to set my IPv6 reverse DNS to
aquitaine.richardskingdom.net?
I should note the mail server works (I am sending this message through
it) so this is only to make the error message go away (and possibly to
get IPv6 mail transportation working correctly).
If this sounds like an ignorant / nonsense request, congratulations, you
have detected successfully that I have no idea what I'm doing with IPv6...
Thanks in advance
Richard.
