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Posts in Networking
Adjusting iprb interface settings with Solaris
I am using an Intel PRO/100 Ethernet inteface in one of the servers I manage, and it is supported by the X64 Solaris 10 Operating System. I recently had to hard code and Intel PRO/100 interface (the Intel PRO/100 is managed by the iprb device driver) to 100 Mb/s full duplex, but it wasn't visible when I ran the ndd utility: I read through the iprb manual page, which discusses hard coding the interface settings in the device driver configuration files. After googling to see which file they were referring to, I found a reference to /kernel/drv/iprb.conf. To set each iprb instance in the server to 100 Mb/s full duplex, the driver type, instance number, speed and duplex parameters can be added to /kernel/drv/iprb.conf: In order for the settings to take effect, the device driver needs to be reloaded, or the server rebooted…
$ read more →Viewing network utilization with iftop
I recently came across the iftop utility, which allows you to view network interface utilization in a top-like display. This can be useful for watching traffic flows on a given interface, or to understand how how much traffic is traversing a given interface. The following picture shows the base iftop display, which contains the SRC and DST IP addresses of the participants, an arrow indicating which way traffic is flowing, and several counters to show traffic sent /received:
$ read more →Network Manager
I came across the NetworkManager application yesterday while looking up some information, and wish I would have found this application earlier in my Linux life! NetWorkManager accepts HAL/DBUS events, and transparently manages the network changes for a user. If you periodically switch between wired and wireless network connections, or wander between wireless access points with different signals levels, NetworkManager might be for you!
$ read more →NAT Variations
Network Address translation (NAT) has become an essential part of the Internet, and is one of the reasons we still have IPv4 address space available. All NAT devices are not created equal though, and several NAT variations are prevalent (per RFC 3489): Full Cone: A full cone NAT is one where all requests from the same internal IP address and port are mapped to the same external IP address and port. Furthermore, any external host can send a packet to the internal host, by sending a packet to the mapped external address. Restricted Cone: A restricted cone NAT is one where all requests from the same internal IP address and port are mapped to the same external IP address and port…
$ read more →Using BIND to reduce ad server content
Internet advertising has become big business, and we see the effects of it in almost every page we view. The ad content typically comes from one or more well known ad servers, and some folks have come up with some clever ways (e.g., hosts files, DNS integration, etc.) to minimize the "ad effect" in the content we view. I have been using Mike's host file for quiet some time, but for some reason OS X (actually lookupd) doesn't handle large hosts files real well. Since OS X would get bogged down during DNS resolution, I decided to merge all of the ad domains into DNS to centrally fix the problem for the clients I support…
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