Tuesday, May 24, 2005

Windows tip: Easy scripts for Media Player

It seems like we spend a lot of time on this blog showing you ways to be more productive or get more out of your routers or your servers. Microsoft recently posted some scripts that, while not really oriented toward productivity, certainly are useful for anyone who uses their Windows Media Player. They’ve created a variety of VBScripts that do everything from exporting song library listings to an Excel spreadsheet to simply playing a particular song. It occured to us that this could also be a great introduction to scripting for anyone who has yet to take the plunge (and it’s fun). Click here to get to their Scripting Center.

Want to know more about working with Windows? Check out our two-day Windows Server 2003 seminar. We cover installation, configuration, optimizing, and troubleshooting. For those of you who have groups of four or more, we’ll bring it onsite to your location. Click here or call 206.988.5858 for more information.

Sunday, May 22, 2005

Linux Tip: See What Hardware is Installed on Your Linux System

Suppose you want to know the exact hardware that’s installed on your system running Linux. You can use lspci to view a listing of most hardware on your system. There may be some unusual or very old piece of hardware that won’t display, but for the most part lspci will show you what’s there. There are several switches that can be used with it to tailor the display for your particular needs. For more information, use man lspci. If it’s not in your path statement, you can usually find it in /sbin.

Want to learn lots more Linux commands? How about getting a good, solid overview of Linux? Our 2-day, hands-on Linux Clinic workshop is perfect for you when you’re looking to jumpstart your Linux experience. Got a group of four or more? We’ll bring it onsite to your location for two days of fast-paced, solution-filled Linux training. Click here or call 206.988.5858 and talk to Janet for all the details.

Wednesday, May 18, 2005

Cisco tip: Restore an IOS image on a 2600

We recently had a classroom situation that required us to copy an IOS image to a router in rom monitor mode using TFTP. I hope you never have to do this, but if you do, it’s helpful to know how. We had copied a new IOS image onto the router which turned out to be corrupted. The old IOS image had already been erased, so the router had no IOS image available for its use. The router returned a rommon > prompt. By using the following series of commands, we were able to download a good IOS image from a TFTP server located at and we were back up and running in about 15 minutes. This procedure uses the first LAN port (in our case ethernet 0/0) and can only be used for downloading a file. It cannot be used to upload a file from the router.

A tip: After you finish configuring the IP address and various related parameters, issue the sync command to copy the settings to NVRAM. That way, if you have to repeat the procedure, at least you won’t have to reenter all the settings.

You can see what settings are already in place by using the set command in ROM monitor mode.

Here’s a step-by-step guide to what you need to do:

rommon 10 > IP_ADDRESS=
rommon 11 > IP_SUBNET_MASK=
rommon 12 > DEFAULT_GATEWAY=
rommon 13 > TFTP_SERVER=
rommon 14 > TFTP_FILE=c2600-c-mz.123-3h.bin
rommon 15 > tftpdnld
TFTP_FILE: c2600-c-mz.123-3h.bin

Invoke this command for disaster recovery only. WARNING: all existing data in all partitions on flash will be lost!Do you wish to continue? y/n: [n]: y

Receiving c2600-c-mz.123-3h.bin from!!!!!!!!!!!!!!!!!!!!!!!!!!!!…File reception completed.

Copying file c2600-c-mz.123-3h.bin to flash.

Erasing flash at 0×607c0000program flash location 0×60440000

rommon 16 >reset[enter]

Want to know more about troubleshooting a Cisco router? Register for any of our upcoming Cisco router training classes. Whether you’re new to routers or have been working with them for years, our Cisco training seminars and workshops offer lots of real world hands-on experience in installing, configuring, optimizing, and troubleshooting. You can attend a public seminar or, for groups of four or more, bring us onsite to your location at the date and time of your choosing. Click here or call 206.988.5858 for details.

Tuesday, May 17, 2005

Cisco tip: Name your access lists

The traditional way of building access lists on a Cisco router is to number them: 1-99 means a standard IP access list, 100-199 means an extended IP access list. It makes a lot more sense to give them a name instead of a number. We have way too many numbers to remember as it is, so having to remember which numbered list does what is just too much. CIOS release 11.2 introduced the ability to name access lists. Now, instead of trying to remember that ACL 101 is designed to block Telnet traffic, we can name it something like “telnet_restrict” so its purpose is obvious.

Use global configuration mode to configure a named ACL. The following sequence of commands configures an IP extended list named restrict_telnet to block telnet (port 23) access from any host to hosts at and on router4’s serial 0/0 and ethernet 0/0 interfaces while permitting all other traffic:

router4#conf t
Enter configuration commands, one per line. End with CNTL/Z.
router4(config)#ip access-list extended restrict_telnet
router4(config-ext-nacl)#deny tcp any host eq 23
router4(config-ext-nacl)#deny tcp any host eq 23
router4(config-ext-nacl)#permit ip any any
router4(config)#int s0/0
router4(config-if)#ip access-group restrict_telnet in
router4(config-if)#int e0/0
router4(config-if)#ip access-group restrict_telnet in

Want to know more about configuring access-lists on a Cisco router? Bring our two-day Cisco Router Fundamentals workshop to your location for groups of four or more in an onsite presentations. Click here or call 206.988.5858 for details and scheduling. Also, check online for public, open-enrollment seminars.

Monday, May 16, 2005

Cisco tip: Load balancing with RIP v1

For internetworks with redundant links between routers, you can use load balancing to distribute traffic across the redundant links. RIP (Routing Information Protocol) does it automatically when there are multiple paths of equal cost to a remote network. The datagrams are allocated to the different paths on a round-robin basis. What’s more, fast switching is enabled by default, offering a more efficient form of load balancing than the alternative of per-packet process switching.

Want to know more about load balancing? Enroll in our two-day Cisco Router Advanced Configuration Procedures workshop, coming to the Pacific Northwest in August. Give us a call at 206.988.5858 or drop us an email and we’ll be sure to let you know when and where. This two-day, hands-on workshop is also available for onsite presentations. That’s where we bring the training right to your door for groups of three or more. Click here or call 206.988.5858 for details and scheduling.

Tuesday, May 10, 2005

Windows tip: Set the time on systems running Windows

As with Linux and Cisco systems, Windows systems like to know what time it is and, when they don’t, they can freak out (and that’s a scary sight). You can set the date manually on NT-based systems (such as NT 4.0, Windows 2000, Windows XP, and Server 2003) with the date command at a command prompt. Similarly, set the time with the time command.

More realistically, you’ll probably want to configure the time centrally from some sort of time source. The Windows 2003 Time Service (W32Time) is configured when you deploy your Forest Root Domain in Active Directory. W32Time uses NTP to synchronize system clocks within a domain. By default, client computers and member servers within an Active Directory domain use their authenticating domain controller as the primary time source. It probably won’t be necessary to perform further configuration on clients and member servers, but if needed you can use the w32tm command at a command prompt. (Use w32tm /? to get options and proper syntax.) On the domain controller, you can also use the w32tm command to specify which Internet time servers to use to acquire the correct time.

You can learn more about working with Windows Server 2003 and Windows XP in our Windows seminars for IT professionals. Our two-day Windows Server 2003 seminar covers the important aspects of installing, configuring, optimizing, and troubleshooting systems running Windows Server 2003 in both standalone and Active Directory environments. Details are available online or call 206.988.5858.

Sunday, May 8, 2005

Linux tip: Set the clock on systems running Linux

Having the correct operating system time is becoming more important today due to the time sensitivity of certain protocols such as LDAP and Kerberos. Even if you’re not currently using such protocols on your systems, accurate time stamping on logs can be a huge aid in troubleshooting and security.

It’s easy to set the time on Linux systems both manually and through NTP. Set the time manually with this command:

#date 0509171405

The above command sets the date and time to May 9 and 5:14 p.m. in the year 2005.

Synchronize with Internet time servers using the Network Time Protocol (NTP) using this command:

#ntpdate [time server URL]

Use multiple time servers by separating each one with a space. Find public NTP servers by using your favorite search engine to query on “NTP servers”. Your Linux/UNIX system may also be running the NTP daemon which will keep the time synchronized. Look for a file such as /etc/ntp.conf on such systems to configure the Network Time Protocol. Learn more about working with Linux in our two-day, hands-on Linux workshop, now available for onsite scheduling for groups of four or more. Bring us onsite to your location and we’ll gladly tailor the training to meet your unique needs. Click here or call 206.988.5858 for complete details.

Cisco tip: Configure the time on a router

Set the router’s time with this privileged EXEC command:

router#clock set [hh :mm:ss] [day of the month] [month] [year]

(Some routers use the calendar command instead of the clock command.)

You can also configure your timezone and daylight savings time using the global configuration mode command clock.

In order to use the timezone command, you’ll need to know your offset from Greenwich Mean Time. Visit http://www.greenwichmeantime.com/ for particulars. To configure your router to synchronize its time with with an Internet time server running the Network Time Protocol (NTP), use this global configuration mode command:

router(config)#ntp server [ip address host name]

Obviously, if you choose to configure NTP with a hostname, you must also configure your router with some means of resolving hostnames to IP addresses such as a name server or a host file. Some low end routers don’t support the NTP command. If your router doesn’t accept it, try the same syntax, but substitute SNTP (Simple Network Time Protocol) for NTP. You can find a listing of public NTP servers by searching online for “NTP servers”.

Learn more about configuring a Cisco router in our two-day Cisco router hands-on workshops. Our two-day classes offer an accelerated learning experience for today’s busy IT professional. The Cisco fundamentals two-day workshop is great for those who are new to routers and our two-day advanced classes offer more in-depth training for those who already understand the basics. Complete details are available online or call 206.988.5858 and enroll today.

Tuesday, May 3, 2005

Cisco tip: Redistribute RIPv2 into RIPv1

Suppose that you have two networks in your internetwork. Devices in one network support the advanced features of RIP version 2, but the devices in the other network don’t. You can still take advantage of the advanced features of RIPv2 in the network that supports it by redistributing the RIPv2 updates into the RIPv1 network. For the purpose of this tip, I assume you’ve already configured RIP version 2 where appropriate.

To route between RIP v1 and RIP v2, use the following procedure:

On the router connected to both networks, configure the following command on the interface connected to the RIPv1 network:

router#conf t
router(config)#interface [interface name]
router(config-if)#ip rip receive version 1

You can gain hands-on experience in techniques just like this, plus many other tips, procedures, and shortcuts when you enroll in our Cisco router training classes. Our accelerated training programs are designed to provide you with practical knowledge combined with lots of hands-on practice so you can go directly from our classroom into your workplace and apply your new knowledge and experience right away. Click here for more information about our Cisco training workshops or call Janet at 206.988.5858 to enroll today.