Author Archives: andrewlaihk
Access to video content in Mainland China which restrict the IP source should be from within the country
Unblock-Youku is an opensource project, their source code is at https://github.com/uku/Unblock-Youku Official site: https://www.uku.im/index_en.html , please donate if you find it is useful. The easier way is use the unblock-youku DNS server(especially good for phones and those TV boxes) main DNS：158.69.209.100 Backup … Continue reading
Fix windows 7 bootup issue using bootrec command
bootrec /fixmbr bootrec /fixboot bootrec /scanos bootrec /rebuildbcd source: https://support.microsoft.com/en-us/kb/927392
Windows 10 with Novemeber update(Threshold 2)
Windows 10 with Novemeber update(Threshold 2) download address ver1511(Build 10586.0) https://www.microsoft.com/en-us/software-download/techbench
Troubleshoot what caused AD account locked
When you as IT get reported from users that the account is locked, do the following: Go to the domain controllers, start event viewer, in windows log->security, click on “filter current log”, enter “4625,4740” as event ID to the box … Continue reading
Path Maximum Transmission Unit (PMTU) Black Hole Routers
Good article explain PMTU black hole routers https://technet.microsoft.com/en-us/library/bb878081.aspx
GRE tunnel
https://en.wikipedia.org/wiki/Generic_Routing_Encapsulation GRE VS IPSEC tunnel http://searchenterprisewan.techtarget.com/tip/GRE-tunnel-vs-IPsec-tunnel-What-is-the-difference Config GRE tunnel using Cisco routers https://supportforums.cisco.com/document/13576/how-configure-gre-tunnel
Use wireshark to inspect and peek into different network layers
Good article: http://www.techrepublic.com/blog/linux-and-open-source/use-wireshark-to-inspect-packets-on-your-network/ Troubleshooting Common Networking Problems with Wireshark, Pt. 1: TCP Checksum Incorrect ‘Error’ Use jperf and wireshark for network troubleshooting http://www.techrepublic.com/blog/linux-and-open-source/use-jperf-and-wireshark-for-troubleshooting-network-issues/
Ethernet, MTU, TCP,IP ,ICMP packet size
Ethernet, MTU, TCP,IP ,ICMP packet size that most IT may not know Standard etherenet packet:1518 Bytes MTU is 1500Bytes =1518-14 etherent header-4 CRC IP header 20Bytes TCP header 20Bytes ICMP header 8Bytes GRE header 4Bytes so total header size is … Continue reading
Vmware certification and cheap course info
I am a VCP5-DCV, for passing it you will need to attend a course and pass the exam. For the course, I attend the VMware vSphere: Install, Configure, Manage course which my company pay for it, for those without company … Continue reading
andrewlaihk 