Windows Network Load Balancing NLB and Cisco Routers/Switches

Problem: Windows NLB IPs are are not reachable through and from Cisco routers and switches. NLB services could be IIS arrays, Exchange CAS arrays, etc. Solution: NLB mode was set to Multicast. In this mode Windows incorrectly uses multicast mac addresses. Set the NLB mode to Unicast and configure static mac address table entries on […]

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Cisco has weird naming conventions for groups of interfaces

If you want to bind some ethernet interfaces into one logical interface between two ciscos switches you have to configure an interface first: interface Port-channel 1 then add some interfaces into this new interface: interface GigabitEthernet 1/0/1         channel-group 1 mode active and you can check the status with: show etherchannel 1 summary Three names

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BGP Looking Glass

If you like to search through the full Internet routing table from around the world, you can find some looking glasses at http://www.traceroute.org/ or http://www.routeviews.org/. e.g. Routeviews has telnet access to zebra servers (route-views.isc.routeviews.org,…)

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Restore data from a single disk of an HP/Compaq SmartArray raid1

If you look into a harddisk from an HP server with smart array configured for raid1, you will recognize that the partition table of this disk has only one partition: Device Boot      Start         End      Blocks   Id  System <device>p3               1           1        8001   12  Compaq diagnostics The real partitions are invisible? No. I found the start of

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Mysqldump: out of memory

A small mysqldump hint: You can use mysqldump –skip-opt to get proper insert statements in the SQL dump. But –skip-opt disables –quick which means mysqldump buffers full tables before writing -> Out of memory. In this case I use: mysqldump –skip-opt –quick <DBNAME>

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Hello world

My daily job is solving IT problems. No matter if they are hardware/software, or os/configuration/application related. There is always a bug to be fixed. And: AlexT Debugs This blog will be the place to remember some solutions to problems, because as time goes by it’s sometimes hard to remember how I debugged. Some solutions will

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