I don't mean to be off topic, but rogue DHCP servers can be easily avoided using switches that support layer-3 ACL's to block dhcp server replies from user ports on switches that support it (all new cisco switches including the 2950's/3550's/37xx's and even smc,dlink,allied telesyn support this). A cisco feature called "dhcp snooping" also prevents rogue dhcp servers. Food for thought.
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Carl Friend Sent: Thursday, August 17, 2006 1:17 PM To: nagios-users@lists.sourceforge.net Subject: Re: [Nagios-users] detect 2 DHCP Servers on network? Hari Sekhon wrote: > [...] raise the warning code if more than 1 offer was received [...] The pitfall here is that if you're running redundant DHCP servers it's possible to receive two offers. ISC DHCPD can function in this way. A regular client would see the first offer, accept it, and ignore the second one; the monitoring script would have to be aware of the network architecture to account for that. One thing you could do is record the IP address(es) of your real DHCP server(s) and if you see anything come in from *anywhere else* raise the alarm. +----------------------------------------------+-----------------------+ | Carl Richard Friend (UNIX Sysadmin) | Natick, Massachusetts | | Minicomputer Collector / Enthusiast | 01760-2098 | | mailto:[EMAIL PROTECTED] +-----------------------+ | http://users.rcn.com/crfriend/museum | ICBM: 42:18N 71:21W | +----------------------------------------------+-----------------------+ ------------------------------------------------------------------------ - Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Nagios-users mailing list Nagios-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nagios-users ::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. ::: Messages without supporting info will risk being sent to /dev/null
