Useful SNMP OIDs
I’ll be adding more to the list as I discover them, but I wanted to record this somewhere outside of Cacti as it was somewhat of a challenge to track down. Cisco Active NAT Translations OID enterprises.9.10.77.1.2.3.0 # snmpget -Of -v2c -c skynet 10.250.10.1 enterprises.9.10.77.1.2.3.0 .iso.org.dod.internet.private.enterprises.9.10.77.1.2.3.0 = Gauge32: 102 Resources Cisco SNMP Object Navigator Cisco [...]
Updating to nfdump 1.6.1 and nfsen 1.3.4
After updating to CentOS 5.5 I received the following when attempting to start nfsen: Starting nfsendPANIC nfsend dies: RRD version ’1.4004′ not yet supported! RRD version ’1.4004′ not yet supported! Previously I had worked around this issue by editing the NfSenRRD.pm file to allow the RRD version I had installed, which obviously isn’t an ideal [...]
Networking Maths
Quick reference for some common and simple equations used in networking, I’ll be adding more as I use/forget them. Number of hosts or subnets: Number of “usable” hosts or subnets: (n being the number of borrowed bits) Number of links required for a full mesh network: or (n being the number of nodes in the [...]
VMWare – Block Size and VMFS 3 Filesize Limts
Quick reference post to remind me of the relationship between block size and max VHD size. Block Size Max VHD Size 1 MB 256 GB 2 MB 512 GB 4 MB 1 TB 8 MB 2 TB
Loopback GPOs – Applying user policies to specific computers
Say you need to create a GPO which modifies user settings, but you only want them to apply when a user logs on to a specific machine. Essentially, you need to link user GPOs to machine accounts. This can be extremely useful when users log into multiple environments, for example, a user may log into [...]
Showing uptime of DSL connections
Quick one today. My usual method of determining ADSL connection uptime has been grepping logs for %LINEPROTO-5-UPDOWN:, %DIALER-6, or most commonly Di0 and looking at the latest timestamps. No more! I knew there had to be a nice and clean show *magic-word* command to make it easier, and there is! Router#sh caller ? full Provide [...]
Deleting sendmail queue
Our monitoring system has gone a bit haywire (my fault), and has started sending me a metric asston of email notifications which should have been suppressed. Luckily, a few more asstons of emails were queued by sendmail and we were able to delete them before it launched a second offensive. There are a few ways [...]
Automatic backup of Cisco configurations
There are several ways to get configs archived and documented, one of the more popular tools seems to be RANCID (I’m yet to try it), another less known tool is config-monitor from iagu networks, but Cisco also provide an inbuilt set of commands which allows a copy of the configuration to be saved remotely via [...]