Mike O''Brien
2009-Feb-02 20:19 UTC
[Xen-users] How to determine DHCP address assigned to client?
Is there any way to interrogate a client to determine what DHCP address was assigned to it? The client, a Fedora 9 domU running on a CentOS 5.2 dom0, has no serial console, so there''s no way to connect to it till I can find its address. Mike O''Brien _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Simon Hobson
2009-Feb-02 20:33 UTC
Re: [Xen-users] How to determine DHCP address assigned to client?
Mike O''Brien wrote:> Is there any way to interrogate a client to determine what >DHCP address was assigned to it? The client, a Fedora 9 domU >running on a CentOS 5.2 dom0, has no serial console, so there''s no >way to connect to it till I can find its address.Use a tool like Wireshark and watch the packets ? If you know the MAC address of the client*, then you can simply look for packets with that MAC address. My preference is to fix this in the guest config file - that way the client doesn''t keep thinking it''s got a new interface each time it boots. -- Simon Hobson Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed author Gladys Hobson. Novels - poetry - short stories - ideal as Christmas stocking fillers. Some available as e-books. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Dustin Henning
2009-Feb-02 20:40 UTC
RE: [Xen-users] How to determine DHCP address assigned to client?
Also, doesn''t your DHCP server have a record of the lease? Or do you not have access to your DHCP server? Regarding the Wireshark suggestion, tcpdump should cut it for what you need. Either of these would likely have to be run on the dom0 due to the fact that the bridge is a virtual switch wherein other domUs wouldn''t see the packets destined for the one in question (just as other machines wouldn''t see the packets headed for the dom0 and it''s domUs assuming it is connected to a switch as well). Dustin -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Simon Hobson Sent: Monday, February 02, 2009 15:34 To: xen-users@lists.xensource.com Subject: Re: [Xen-users] How to determine DHCP address assigned to client? Mike O''Brien wrote:> Is there any way to interrogate a client to determine what >DHCP address was assigned to it? The client, a Fedora 9 domU >running on a CentOS 5.2 dom0, has no serial console, so there''s no >way to connect to it till I can find its address.Use a tool like Wireshark and watch the packets ? If you know the MAC address of the client*, then you can simply look for packets with that MAC address. My preference is to fix this in the guest config file - that way the client doesn''t keep thinking it''s got a new interface each time it boots. -- Simon Hobson Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed author Gladys Hobson. Novels - poetry - short stories - ideal as Christmas stocking fillers. Some available as e-books. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
James Harper
2009-Feb-02 22:23 UTC
RE: [Xen-users] How to determine DHCP address assigned to client?
> > Is there any way to interrogate a client to determine what DHCP > address was assigned to it? The client, a Fedora 9 domU running on a > CentOS 5.2 dom0, has no serial console, so there''s no way to connect > to it till I can find its address. >A few options... . You could get the machine to publish it''s IP in xentstore . use something like arpwatch in the logs of Dom0 and then grep for the IP address . examine the DHCP lease database . use tcpdump with an ''ether src <mac of client>'' filter . nmap -sP <subnet> and then examine the arp cache James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Ryan Knapper
2009-Feb-02 22:49 UTC
Re: [Xen-users] How to determine DHCP address assigned to client?
How many hosts are on your subnet? You could ping your broadcast address and see who responds. On Mon, Feb 2, 2009 at 12:19, Mike O''Brien <obrien@aero.org> wrote:> Is there any way to interrogate a client to determine what DHCP > address was assigned to it? The client, a Fedora 9 domU running on a CentOS > 5.2 dom0, has no serial console, so there''s no way to connect to it till I > can find its address. > > Mike O''Brien > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >-- [EOM] _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Ricardo J. Barberis
2009-Feb-04 01:50 UTC
Re: [Xen-users] How to determine DHCP address assigned to client?
El Lunes 02 Febrero 2009, Mike O''Brien escribió:> Is there any way to interrogate a client to determine what DHCP > address was assigned to it? The client, a Fedora 9 domU running on a > CentOS 5.2 dom0, has no serial console, so there''s no way to connect > to it till I can find its address. > > Mike O''BrienMaybe simpler: did you enable vnc on domU''s config file? If so, you can connect a vncviewer on dom0''s IP and port 5900+domU''s ID and check from there. But really, you should use static mac addresses and also static IPs if possible to save yoursefl from future headaches :) Best regards, -- Ricardo J. Barberis Senior SysAdmin - I+D Dattatec.com :: Soluciones de Web Hosting Su Hosting hecho Simple..! _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users