Re: Preventing a Network Service from becoming Primary
Re: Preventing a Network Service from becoming Primary
- Subject: Re: Preventing a Network Service from becoming Primary
- From: Ben Low <email@hidden>
- Date: Fri, 3 Nov 2006 01:58:56 +1100
On 03/11/2006, at 1:32 AM, Allan Nathanson wrote:
...
But when it comes to VPNs, it doesn't make sense - these can only
ever be the default when there is an explicit route to the server
already in the route table - a conditional default at best, if you
will.
But it also doesn't make sense for the VPN to be active when the
server is no longer accessible.
Sure - but how does a VPN that uses a connectionless transport know
when the server no longer accessible?
(and having the vpn close down is only a mitigation - I still propose
that the "correct" solution is to be able to prevent a route from
being promoted to default / "primary"; and in that situation my
little vpn doesn't even have to close down, while it'll be on dead
air it can still carry any crypto state and such over until the
underlying transport comes back...)
Have you looked at the SCNetworkReachability APIs (specifically,
starting with SCNetworkReachabiltyCreateWithAddressPair)? FWIW,
I'd avoid using a kicker script.
For the benefit of the tape (typo):
SCNetworkReachabiltyCreateWithAddressPair =>
SCNetworkReachabilityCreateWithAddressPair
So the idea would be to patch openvpn to use SCNetworkReachability to
be signalled when the server's no longer reachable - sounds good, but
won't SCNetworkReachability also get tripped up by the promotion of
the openvpn default? When the real links go away, and up until
openvpn exits, the o/s believes everything's rosy with the default
via the tun0 interface...
Rgds,
Ben
--
Ben Low
email@hidden
"I am not young enough to know everything." - Oscar Wilde (1854-1900)
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Macnetworkprog mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden