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bringing up CTs with duplicate IP addresses [message #28964] Wed, 02 April 2008 15:26 Go to next message
swindmill is currently offline  swindmill
Messages: 57
Registered: April 2007
Member
It has come to my attention that if the mistake is made to attempt to bring up a CT with an IP address that is already being used elsewhere the following message is displayed:

Adding IP address(es): x.x.x.x
arpsend: x.x.x.x is detected on another computer : 00:MA:CA:DD:RE:SS
vps-net_add WARNING: arpsend -c 1 -w 1 -D -e x.x.x.x eth0 FAILED

The CT is then started, and the IP address in question is still assigned.

The network is available from inside of the newly started CT, but obviously the external network is confused.

Should vzctl instead fail and not start the CT if this error is detected?

vzctl version 3.0.22
2.6.18-53.1.6.el5.028stab053.6

[Updated on: Wed, 02 April 2008 15:45]

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Re: bringing up CTs with duplicate IP addresses [message #28966 is a reply to message #28964] Wed, 02 April 2008 15:33 Go to previous messageGo to next message
TheWiseOne is currently offline  TheWiseOne
Messages: 66
Registered: September 2005
Location: Pennsylvania
Member
I notice this same bug.

]# rpm -q vzctl ovzkernel
vzctl-3.0.16-1
ovzkernel-2.6.18-53.1.6.el5.028stab053.6


Matt Ayres
TekTonic
Re: bringing up CTs with duplicate IP addresses [message #29187 is a reply to message #28964] Tue, 08 April 2008 13:47 Go to previous messageGo to next message
TheWiseOne is currently offline  TheWiseOne
Messages: 66
Registered: September 2005
Location: Pennsylvania
Member
Was a bug report ever opened for this?

Matt Ayres
TekTonic
Re: bringing up CTs with duplicate IP addresses [message #29230 is a reply to message #28964] Wed, 09 April 2008 07:31 Go to previous messageGo to next message
maratrus is currently offline  maratrus
Messages: 1495
Registered: August 2007
Location: Moscow
Senior Member
Hello,

vzctl generates only warning to be closer to common Linux machine behavior. If you have a common computer and assign on this machine an IP address which intersects with some another on the external node your machine won't refuse to start. The same way with CT behavior.

P.S. But it's impossible to assign the equal IP to different VE's on the same HN because kernel prohibits to do this.
Re: bringing up CTs with duplicate IP addresses [message #29248 is a reply to message #28964] Wed, 09 April 2008 14:55 Go to previous message
TheWiseOne is currently offline  TheWiseOne
Messages: 66
Registered: September 2005
Location: Pennsylvania
Member
This is actually a good idea for failover scenarios...

Matt Ayres
TekTonic
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