Last week I noticed logging on my RES Service Store lab-environment took 10+ seconds, instead of the 4 seconds I was used to. The only thing I changed the past week was the implementation of a Citrix NetScaler VPX in my homelab, for externally serving both RES-ONE.nl and my RES Service Store lab-environment. After some Googling I stumbled upon a thread on the Citrix Discussions Board about Slow Load Balancing of a webfarm in which someone suggested to look at Citrix KB-article CTX118670.
This CTX-article suggests to disable NetBIOS over TCP/IP on your IIS Webservers since NetScaler doesn’t respond on the NBNS queries and delays logging in. After disabling NetBIOS over TCP/IP (also mentioned in CTX139486 to Improve the Log on Performance in StoreFront), logging in went from 12 seconds down to 4 seconds!
Disabling NetBIOS over TCP/IP
Disabling NetBIOS over TCP/IP is done by a couple of steps:
- Open Network Interface Adapter properties
2. Click Advanced… to open the properties window for TCP/IP
3. In the WINS tab, select Disable NetBIOS over TCP/IP radio button
Difference between NetBIOS over TCP/IP enabled and disabled
To showcase the difference in logon time, I recorded both situations with a little tool called ScreenToGif. The first situation shows the Logon with NetBIOS over TCP/IP enabled and the second with NetBIOS over TCP/IP disabled.
Situation with NetBIOS over TCP/IP enabled:
Situation with NetBIOS over TCP/IP disabled: