OS on Blog - uTIcARdI

openwrt DDNS, acme commands

Wed, 15 Sep 2021 00:00:00 +0000

I’m using OpenWrt R21.8.6 by compile it from coolsnowwolf/lede.

1. Install softwares on Openwrt

acme
ddns-scripts (This originally built when compile the firmware)

2. DDNS configuration

DNS System

Creating a dynamic DNS record on your DNS service provider (Mine is running over dns.he.net)

Dynamic DNS A Record - New

Generate password for DDNS

File name on windows

Fri, 01 Mar 2019 00:00:00 +0000

Error 1

Run a bat (ping.bat) to ping multiple IPs like this:

set testipa=x.x.x.x
echo Checking ping %testipa% (15 times), please don't close current window
echo ping %testipa% (15 times) >> test.log
ping %testipa% -w 500 -n 15 >> test.log

But got the following error:

Checking ping x.x.x.x (15 times), please don't close current window
The process cannot access the file because it is being used by another process.
The process cannot access the file because it is being used by another process.

Monitor network connections based on Process

Fri, 21 Sep 2018 00:00:00 +0000

Wireshark is widely used in packets capturing with flexible filters, but for some particular cases, end users care about the network sessions which established by a specific application.

I will show how to check the sessions of ‘Microsoft OneNote’.

Windows

Microsoft provides its own product for packets capturing: Microsoft Network Monitor.

Lunch ‘Microsoft Network Monitor’ before you run OneNote:

nm-1

You will see the processes from the left panel, All related network sessions will shown in the ‘frame summary’ window once OneNote lunched:

tc-How it work on different IPs

Fri, 22 Sep 2017 00:00:00 +0000

#!/bin/bash
interface=eth0
ip1=192.168.1.1
ip2=172.16.1.1
delay1=100ms
delay2=200ms
tc qdisc add dev $interface root handle 1: prio
tc qdisc add dev $interface parent 1:1 netem delay $delay1 10ms 25%
tc filter add dev $interface parent 1: protocol ip prio 1 u32 match ip dst $ip1 flowid 1:1
tc qdisc add dev $interface parent 1:2 netem delay $delay2 10ms 25%
tc filter add dev $interface parent 1: protocol ip prio 2 u32 match ip dst $ip2 flowid 1:2

Adding Realtek 8139 Driver to ESXi6

Tue, 29 Nov 2016 00:00:00 +0000

Note: This is not an official guide, backup is required before you apply the driver.

My Dell PC has two NICs:

Intel I217-LM
Realtek RTl-8139

and #2 Realtek 8139 is not supported by VMware EXSi.

There are some guides about customizing EXSi installation ISO to support the NIC, but I’m trying to find a way to apply the driver without reinstall EXSi.

Here is a page which contains many NIC drivers: https://vibsdepot.v-front.de/wiki/index.php/List_of_currently_available_ESXi_packages

Run Ansible on Windows

Tue, 29 Nov 2016 00:00:00 +0000

Background:

Here is a topology about the environment for performance testing, let’s name the servers 1st:

1 windows server as the License/Workspace server
5 windows servers as the Network Server
5 windows servers as the Automation server

Topo

It took us a lot of time to deploy the product and collect logs on all of these servers.

VSphere6, VCenter6 Installation

Fri, 08 Jan 2016 00:00:00 +0000

Crash happened when I install Vsphere on my PC

Solution: Disable option “Limit Maximum CPUID” in Bios
VCenter appliance deployment

Vmware doesn’t provide vcenter appliance in ova/ovf format anymore, follow the instruction to deploy it.
Inventory is empty in the VCenter webpage

The most important thing: Don’t login vcenter by the account ‘root’, instead of it using SSO account. the account in the format: ‘administrator@domain-name’

Also, Vmware has a KB about this issue:

Open LDAP and SSH Public key

Fri, 08 Nov 2013 00:00:00 +0000

The article is about how I setup Open LDAP on CentOS6 for SSH public key authentication.

1.Download and install CentOS6.2

CentOS-6.xx-i366-minimal.iso

2. CentOS configuration

Network: IP address, DNS, and restart network service

vi /etc/resolv.conf/DNS
vi /etc/sysconfig/network-scripts/ifcfg-eth0/NIC IP
vi /etc/networks//Route
/etc/init.d/network restart

configure host file
```
vi /etc/hosts
```
Modify 127.0.0.1 item to FQDN format because openldap get dc from the item automatically.
```
127.0.0.1 ldap.kzblog.com
```
Stop security services
```
setenforce permissive
getenforce
service iptables stop
```
Note: This only for the testing environment.

make error :/usr/bin/ld: cannot find -luuid

Tue, 05 Nov 2013 00:00:00 +0000

I met a make error in CentOS 6:

# make

......

/usr/bin/ld: cannot find -luuid
 ld returned 1 exit status
make: *** Error 1

The way to fix this error is to install lib : uuid-devel

yum -y install libuuid-devel