Cisco Jumbo frame setting

February 13, 2014 Leave a comment

Here is a little tidbit to remember. I was configuring a switch for a new iSCSI SAN install. To make it easier I was copying configuration settings from an existing SAN switch when I noticed there was nothing setting the Jumbo frames to 9000. I verified everything was ok on the production network by using ping, setting the size, and telling it not to fragment. I then used a show system MTU command and the switch shows Jumbo MTU set to 9000. I little searching online and I found that Cisco switches don’t store the Jumbo frame setting in the configuration file. Here is the quote from the Cisco documentation:

The system MTU setting is saved in the switch environmental variable in NVRAM and becomes effective when the switch reloads. Unlike the system MTU routing configuration, the MTU settings you enter with the system mtu and system mtu jumbo commands are not saved in the switch Cisco IOS configuration file, even if you enter the copy running-config startup-config privileged EXEC command. Therefore, if you use TFTP to configure a new switch by using a backup configuration file and want the system MTU to be other than the default, you must explicitly configure the system mtu and system mtu jumbo settings on the new switch and then reload the switch.

Categories: Cisco Tags: , ,

Reminder of the incandescent light bulb ban

November 24, 2013 2 comments

Just a quick reminder to pickup whatever stock you think you might need.  Reference this post

I was just at the store and there are no 100W or 75W bulbs to be found.  Good supply of 60W for now.

I’ve gone to LED for the can lights in the kitchen and they work great.  There is a fraction of a second delay between turning on the switch and the light coming on, but they come on at full brightness so I can deal with that.  Slowly working on replacing all the CFL flood light bulbs with LEDs.  LED prices are still too high for all the fixtures in the house so I’ve stocked up with a supply that should last about a decade.  By that time the price should be better, or I will have won the lottery :)

Printer supply monitoring with SNMP and PRTG

August 30, 2013 Leave a comment

I finally found a simple to use but very powerful network monitoring package. All I wanted was something like MRTG to tell me how much bandwidth was being used on our WAN links. Because of our strict security requirements we were not allowed to use MRTG. I stumbled across PRTG Network Monitor and it worked perfectly for showing network bandwidth. After digging through it a bit more I found that it could do much more. I am now using it to monitor all the hardware on our network. From routers and switches to servers and SANs. Today I was able to configure monitoring for all our printers, including toner levels. The hardest part with the printers was finding the correct MIBs. Hopefully this post will help the next person. Read more…

Categories: Computing Tags: , , ,

Outlook 2010 show picture placeholders

May 3, 2013 4 comments

This little setting cost me a few hours of time. I have no idea how it got messed up but I have the fix. The problem is e-mails wouldn’t show images, only boxes where the image is supposed to be. It took me just a few minutes to find the setting. With a message open click File -> Options -> Editor Options… -> Advanced -> Show picture placeholders. So I uncheck the box and the pictures show up in the e-mail. All is good until the next day when I start Outlook again and the setting is checked again. No matter what I do I can’t seem to get the setting to stay unchecked. Well here is the fix. Read more…

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Migrate clients to a new DHCP server

May 2, 2013 Leave a comment

We’ve decided to migrate our DHCP services off the domain controllers and onto a DHCP failover cluster.  We needed to find a way of getting the clients to migrate over without rebooting them and without the sledge hammer approach of turning off the old DHCP service.  We came up with a slow and safe method for forcing the clients to migrate with minimal impact.   Read more…

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SharePoint 2010 warm up

August 2, 2012 Leave a comment

We are just now getting ready to role out SharePoint Foundation 2010 on our network.  One thing that has always bothered me with SharePoint is how terribly slow it is when the first user hits the site.  After much research it seems most people use what’s called a warm up script to hit the sites.  As usual, nothing is ever easy.  Most of the scripts I found didn’t work.   Read more…

Exchange 2010 EMC and EMS are very slow

July 23, 2012 1 comment

I’ve been working with a new installation of Exchange 2010 for the last couple weeks.  Today, I finally got tired of waiting so long for the Exchange Management Console (EMC) and Exchange Management Shell (EMS) to start up on my management workstation.  This only happens because our network isn’t connected to the Internet.   The solution was to open Internet Explorer options advanced tab.  Scroll down to the Security section and uncheck “Check for publisher’s certificate revocation”.

I found the idea from this posting but I didn’t need to uncheck the second setting he has there since we have a fully operational private PKI infrastructure in place.  This is safe for us to do in our environment because of our isolation.


Categories: Computing Tags: , , ,

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