Tag Archives: Networking

Real-time ethernet bandwidth utilisation

04/12/2010 – 13:40

Some weeks ago one of my colleagues asked me how could he monitor the traffic rate of the ethernet network. There is the netperf tool which you can get from the porting center, however that is more of a network troubleshooter tool than a real-time monitoring software. Now I found a nice perl script which [...]

By Viktor Balogh | Posted in HP-UX system administration, Languages and Scripting, Monitoring, Networking | Also tagged , , , , , , | Comments (0)

How autonegotiation supposed to work

06/01/2010 – 14:15

Here is a quick guide on how autonegotiation supposed to work: When both sides are set to autonegotiation, they will negotiate the speed and the duplexity and the maximum supported will be the common speed/duplexity. If one side is hardcoded and the autonegotiation is set to off, the autonegotiation process will fail, and the side [...]

By Viktor Balogh | Posted in Networking | Also tagged , , , | Comments (0)

Firewall in HP-UX

20/08/2009 – 15:29

In most datacenters it is very uncommon to use a firewall directly on the server. However, in HP-UX it is on as a default. To check the status of the firewall: # ipfstat dropped packets:        in 0    out 0 non-data packets:       in 0    out 0 no-data packets:        in 0    out 0 non-ip packets:         in 0    [...]

By Viktor Balogh | Posted in HP-UX, HP-UX general, Networking, Security | Also tagged , , | Comments (7)

Permanent LAN settings howto

27/06/2009 – 16:03

This is a short howto on how to preserve the speed, duplexity and MAC settings for a network interface on HP-UX to survive a reboot. First, list the network interfaces with ioscan! # ioscan -fknC lan Class     I  H/W Path     Driver   S/W State   H/W Type     Description ======================================================================== lan       0  0/1/2/0      igelan   CLAIMED     INTERFACE    HP PCI [...]

By Viktor Balogh | Posted in HP-UX system administration, Networking | Also tagged , , | Comments (2)

Interrupting unreachable NFS at boot

26/06/2009 – 19:54

If the NFS server hangs and we realized it only after booting our NFS client, we will be presented with a boot message like this: Start NIS server subsystem …………………………………… OK Start ldap client daemon …………………………………….. N/A Start NIS/LDAP server subsystem ………………………………. N/A Start NIS client subsystem …………………………………… OK Start NFS client subsystem …………………………………… NFS [...]

By Viktor Balogh | Posted in HP-UX system administration, Networking | Also tagged , | Comments (5)

The process to replace a failed PCI card with OLA/R

08/05/2009 – 09:01

Identify the failed PCI card Perform critical resource analysis on the affected PCI card Turn on the attention light for the affected PCI card slot Check that the affected PCI slot is in its own power domain Check that the affected PCI card slot is not a multi-function card Run any associated driver scripts before [...]

By Viktor Balogh | Posted in Hardware, HP-UX general, Servers | Also tagged , , , , | Comments (0)

Xen Network Bridges

26/04/2009 – 20:18

The following outlines what happens when the default Xen networking script runs on single NIC system: The script creates a new bridge named xenbr0 “Real” ethernet interface eth0 is brought down IP and MAC addresses of eth0 are copied to virtual network interface veth0 Real interface eth0 is renamed peth0 Virtual interface veth0 is renamed [...]

By Viktor Balogh | Posted in Virtualization | Also tagged , , | Comments (0)