Tag: unequal

  • Configuring Dedicated Trunks for the CSM

    Did you catch the article on setting up fault tolerance on the CSM?  In that article, I mentioned that Cisco recommends a dedicated trunk for the FT VLAN if you have two HA CSMs in two chassis.  Discuss amongst yourselves while I drone on. Why should you set up a dedicated trunk for this stuff? 

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  • Using Probes on the CSM

    There are three different ways that a CSM checks for the health of the servers — active probes, inband health checking, and inband HTTP monitoring.  Let’s talk about active probes. Active probes (or just probes) typically send traffic to one of the RIPs of a serverfarm, do some stuff, and give a pass or fail

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  • Using CDP To Track Down Physical Connections

    We have a location that’s a few blocks down from the main office here, and we were reviewing the circuit size to make sure it was sized properly.  Since not one person knows what’s going on and the trending graphs gave us conflicting details, one of our network dudes took me down to the site

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  • Using MAC Access-lists

    We ran into this today, and, though I knew it existed, I never actually saw it in the wild.  I’m talking about MAC access-lists. In the example setup, we have a DMZ off of a firewall that contains a whole mess of servers — email, web, ftp, etc.  These should all be in the DMZ

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  • Configuring Fault Tolerance on the CSM

    Like (nearly) everything in the Cisco world, you can set up your CSM to fail over to another module when the primary dies a horrible death.  You can have two in the same chassis or even have them in separate chassis — the process is the same no matter how you have it set up. 

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  • Setting Up Syslog on a Linux Box for Your IOS Devices

    A few articles ago, we discussed getting logging up and running on your IOS box.  Part of the discussion was actually having the device log remotely to a box somewhere, but that’s kind of worthless without a properly (for definitions of proper) configured syslog server.  A low-end Linux box with an appropriate amount of disk

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  • Running Multiple Data Centers on a Stick with the CSM

    That’s an awesome title, eh?  I’ve mentioned a router-on-a-stick before but not a data-center-on-a-stick (DCOAS).  This is one of those Cisco terms I ran across a while ago and is a group of servers sort of sticking out on their own behind a load balancer and/or firewall.  Connections to and from the server group go

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  • Setting Up System Logging on an IOS Device

    I like logging on an IOS device.  I like to look at the buffer and tell you that your interface went down 30 seconds ago.  I like to look on the box and see that BGP with my Internet provider has been flapping since 02:13ET.  I like to look and see that one of the

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  • Back to Basics — CAM Table Population

    At the office, we reprovision servers like it’s going out of style.  It happens so often that my cabling documentation rarely matches what’s actually out in field, which is a pretty big problem when you’re trying to find to what switch port a server is connected.  I finally relegated myself to asking for the MAC

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  • How Screen Can Change Your Life

    Alright, that’s an exaggeration, but screen is pretty freaking cool.  It’s an app that’s (usually) run under Linux that lets you run commands then detach from that session and reattach later.  It doesn’t seem like much, but a few examples can show what it does for me. I have a backup script at home that

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