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Posts in Networking
Isolating network traffic with IP instances
With the introduction of Nevada build 57, the Solaris IP stack was enhanced to support IP instances. IP instances allow you to create one or more unique TCP/IP stacks on a server, and each stack can be managed independently. What makes these extremely powerful is the ability to assign an IP instance to a zone or Xen instance, and then configure the IP stack attributes (e.g., IP filter policies, DHCP settings, etc.) from inside the zone or Xen guest domain. To create an IP instance and assign it to a Solaris zone, you will first need to identify a spare physical NIC to dedicate to the zone (when Crossbow comes around, you will be able to allocate virtual NICs to zones, and these virtual NICs can reside on a physical NIC)…
$ read more →Preventing domain expiration article
I just came across Rick Moen's Preventing Domain Expiration article. Rick did a great job with the article, and it's cool to see that they took my domain-check shell script and implemented it in Perl. The Perl version supports for TLDS, and contains a bit more functionality than the bash implementation. If I get some time in the next few months, I will have to update the domain-check bash script to support the same TLDs as the Perl implementation…
$ read more →Taking IPMP managed interfaces online and offline
I use Solaris IPMP (IP multipathing) on several of my servers to allow them to keep operating in the event that a network interface or switch were to fail. Periodically I need to take IPMP managed interfaces offline, but I need to keep the IP addresses attached to those interface up and operational. Solaris comes with the if_mpadm utility, which provides a simple and straight forward way to take IPMP managed interfaces online and offline. Prior to using the if_mpadm utility, it is useful to check the status of the interface you want to take online or offline…
$ read more →Accessing Windows shares from the Solaris/Linux command line
Periodically I need to access a Windows share from a Solaris or Linux box. If Samba is installed on the system, this is easy to do with the smbclient utility. To access the Windows server named "milton" from the command line, you can run smbclient with the "-U" option, the name of the user to authenticate with, and the name of the server and share to access: In this example, I am authenticating as the user matty in the domain "domain," and accessing the share foo on the server milton. If smbclient is unable to resolve the server, you will need to make sure that you have defined a WINS server, or the server exists in the lmhosts file…
$ read more →Logfile format for BIND queries
While perusing my BIND query logs, I came across the following entry: All of the text up to the record type (MX in this case) made sense, but I had no idea what the "-E" meant. Being the curious person I am, I dug through the BIND source code to locate the logging code. After a couple of find statements, I was able to locate the logging code in query.c: So a "+" or "-" in a query log entry indicates that a client requested recursion, and the "E" means that the query requested EDNS0. I would like to thank Knobee for his feedback on this post.
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