The entries in the /proc/meminfo can help explain what’s going on with your memory usage, if you know how to read it.
Example of “cat /proc/meminfo”:
root: total: used: free: shared: buffers: cached: Mem: 1055760384 1041887232 13873152 0 100417536 711233536 Swap: 1077501952 8540160 1068961792
Courtesy of Keith Barker
Another aide-memoir:
daren@Shimla:~$ sudo apt-get install wireshark
[sudo] password for daren:
Reading package lists… Done Read more…
For SuperMicro motherboards which use IPMI, you can setup monitoring of RPS’s using Nagios and the IPMI plugin.
IPMItool is an open source utility to work with the IPMI management cards in some servers. Depending on your particular Linux distribution, you can probably “apt-get install ipmitool” or “yum install ipmitool” to get it. It is basically a command line tool that can be used instead of the IPMI web interface. Read more…
An aide-memoir from practicing iproute2, the utilities used to control TCP/IP networking and Linux Traffic Control
“ip link list” – shows us our links
[Daren@home Daren]$ ip link list
1: lo: <LOOPBACK,UP> mtu 3924 qdisc noqueue
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: dummy: <BROADCAST,NOARP> mtu 1500 qdisc noop
link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
3: eth0: <BROADCAST,MULTICAST,PROMISC,UP> mtu 1400 qdisc pfifo_fast qlen 100
link/ether 48:54:e8:2a:47:16 brd ff:ff:ff:ff:ff:ff
4: eth1: <BROADCAST,MULTICAST,PROMISC,UP> mtu 1500 qdisc pfifo_fast qlen 100
link/ether 00:e0:4c:39:24:78 brd ff:ff:ff:ff:ff:ff
3764: ppp0: <POINTOPOINT,MULTICAST,NOARP,UP> mtu 1492 qdisc pfifo_fast qlen 10
link/ppp
Read more…
SNMP v3
Download this capture file: ” snmp_usm ”
OR: view it now via Cloudshark
SNMPv3 provides a secure environment for the management of systems covering the following: Read more…
The challenge was to obtain all user IP addresses in order to locate them on the local LAN (i.e. to locate their switch port by checking arp caches and mac address-table entries in the usual manner). Once located I needed to place them into a different vlan and then have the user reboot to obtain a new IP address. How could I accomplish this remotely and by “stealth”. Read more…
This post describes the tasks required for a basic configuration of the Cisco ASA. Please note that he smaller Cisco ASA 5505 has an 8-port 10/100 switch which operates at Layer 2 only. So you can not configure the physical ports as Layer 3 routed ports, you need to create VLAN interfaces. By default, interface Ethernet0/0 is assigned to VLAN 2 and it’s the outside (internet-facing or untrusted)interface. The remaining seven interfaces (Ethernet0/1 to 0/7) are assigned to VLAN 1 Read more…
+————-+—————————+
| Expression | Meaning |
|————-+—————————|
| .* | Anything |
|————-+—————————|
| ^$ | Locally originated routes |
|————-+—————————|
| ^100_ | Learned from AS 100 |
|————-+—————————|
| _100$ | Originated in AS 100 |
|————-+—————————|
| _100_ | Any instance of AS 100 |
|————-+—————————|
| ^[0-9]+$ | Directly connected ASes |
+————-+—————————+
Read more…
System Shut Down
shutdown -h now (Displays the file hello.txt)
shutdown -h +15 (Displays the file hello.txt)
shutdown -r now (Shut Down > Restart now)
shutdown -r +15 (Shut Down > Restart in 15 minutes)
IP Configuration (Edit the ifcfg-eth0 file):
cat /etc/sysconfig/network-scripts/ifcfg-eth0 View the configuration file for eth0
vi /etc/sysconfig/network-scripts/ifcfg-eth0 Edit and Save the configuration file for eth0 Read more…
