On Wed, 10 Nov 2010 17:01:37 +0200 Timo wrote: TT> Looking at agent/mibgroup/ip-mib/data_access/arp_linux.c it's doing TT> snapshot dumps from the kernels tables, and apparently higher layers are TT> doing the caching.
Yep. You could set the cache timeout lower if you wanted fresher data, but there will always be that window where the cache could be a little stale. TT> Now, I'm asking which is better, and if there's any existing example TT> code (so I can fix the arp_linux.c): TT> TT> 1) Dynamically listen Linux netlink events and add/delete/update TT> entries on the snmpd's copy of ARP table? TT> TT> -or- TT> TT> 2) On request to specific IP-address (specific MIB entry with IP TT> address part of the request OID), request the kernels for up-to-date TT> information on that specific IP-address and dynamically create the result? I'd vote for 2. You'd just have to disable the cache reload at the higher levels (there are some flags that can be set when the cache is created) and keep the cache consistent via netlink. There is already some code in net-snmp that is using netlink grep should help your find where that is. just make sure that you are using the agent's main select loop to monitor the netlink socket. If the code was configurable at runtime, that would be ideal. People who aren't monitoring/using the arp module might not want the overhead of an unused cache being constantly updated. ------------------------------------------------------------------------------ Centralized Desktop Delivery: Dell and VMware Reference Architecture Simplifying enterprise desktop deployment and management using Dell EqualLogic storage and VMware View: A highly scalable, end-to-end client virtualization framework. Read more! http://p.sf.net/sfu/dell-eql-dev2dev _______________________________________________ Net-snmp-coders mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/net-snmp-coders
