Table of Contents
Command line program to test DHCP service
From: https://serverfault.com/questions/171744/command-line-program-to-test-dhcp-service
assuming you have installed nmap (sudo apt install nmap): sudo nmap --script broadcast-dhcp-discover Windows nmap -sU -p 67 --script dhcp-discover 10.230.0.2/32
Get-DhcpServerInDC
nmap -oA c:\temp\nmap-broadcast-dhcp-discover-2020-07-21 --script=broadcast-dhcp-discover 10.9.0.0/16
http://marcushall.net/dokuwiki/doku.php
File broadcast-dhcp-discover
Name Resolution Lookup
Microsoft TCP/IP Host Name Resolution Order
Name resolution lookup windows 7
DHCPFind search active and rogue DHCP servers
From: http://www.symantec.com/connect/downloads/detect-rogue-dhcp-servers-network
Fromn: http://www.roadkil.net/downloads.php
Find DHCP displays the DHCP servers active on your network, just run this portable tool and in few seconds will be shown many helpful information such as IP address offered by dhcp server, netmask, gateway, servers network address and dhcp lease.
RogueChecker - Find DHCP servvers
From: https://robiulislam.wordpress.com/2012/11/12/rogue-dhcp-server/
Downloads: http://blogs.technet.com/b/teamdhcp/archive/2009/07/03/rogue-dhcp-server-detection.aspx http://blogs.technet.com/cfs-file.ashx/__key/communityserver-components-postattachments/00-03-26-09-62/RogueChecker.zip
Network Discovery
Network discovery is not a single thing. In general terms it is the process of gathering information about the Network resources near you. It consists of a group of protocols that all report to the Function Discovery platform. Probably the most well-known protocol is NetBIOS Browsing, but it also includes WSD, UPNP, SSDP, and even the registry. Typically you see this information in Network Resources/Network Neighborhood, but any application can potentially be programmed to use it.
Clearing the network configuration
runs Ipconfig release, flushdns, renew, registerdns When they return to the office, they cannot access network resources. They receive a DHCP address, but cannot connect to their shared drive, cannot synchronize and cannot surf the web. If an "ipconfig /release" and "ipconfig /renew" is performed, all is well again. Looking deeper into the problem, the "Connection-specific DNS Suffix" is not correct.
Does your PC have any IPv6 addresses (link-local or otherwise)?
ipconfig /all | findstr IPv6
What IPv6 endpoints are on your Windows machine?
netstat –abn –p tcpv6 netstat –abn –p udpv6 netstat –abn –p icmpv6
From <http://techgenix.com/IPv6-multicast-background-traffic-Part1/>
Use ip . I want to know about your world Are you still using one of the following tools?
/bin/netstat (replaced by ss, for which I’ll dedicate another blog post entirely) /sbin/ifconfig /sbin/ipmaddr (replaced by ip maddress) /sbin/iptunnel /sbin/mii-tool (ethtool should appropriately replace it) /sbin/nameif /sbin/plipconfig /sbin/rarp /sbin/route /sbin/slattach
From <https://ubuntu.com/blog/if-youre-still-using-ifconfig-youre-living-in-the-past>
Troubleshooting Windows File Sharing
From: http://community.wd.com/t5/WD-TV-Live-Networking/Troubleshooting-Windows-File-Sharing/td-p/92642
net view nbtstat -a kids-vm-pc net view /domain nbtstat -A 10.0.0.2 net view \\bignas1
Network anomalies
- Windows 8 computer (not domain member) will only list WSD discoveries for computers
- Added Wins server manually (would not add from DHCP automatically)
- then listed netbios computers quickly
- Same computer left building to home network and became computer browser of home network
- retained master browser status when DHCP configured for work network
- and even with manual wins configuration would only discover itself with netbios
- after runs Ipconfig release, flushdns, renew, registerdns still retains master browser
netstat
netstat -an netstat -bano = show the application that is listening nbtstat -A 192.168.1.10
6. View current TCP connections
Get-NetTCPConnection
From <https://www.techrepublic.com/article/10-powershell-commands-for-network-troubleshooting/>
Network Investigation Commands
From: http://technet.microsoft.com/en-us/magazine/ee924647.aspx
When the troubleshooters don’t solve the problem
From: http://whirlpool.net.au/wiki/windows_nw_diag_cmds
network diagnostic
57 Tips Every Admin Should Know
From: http://www.gfi.com/blog/57-tips-admin/
all network connections ipconfig /release whoami /groups systeminfo | more Active Directory listing commands
Microsoft Computer Browser Service
Note: Samba on linux as default will claim Master Browser
How to Determine the Master Browser in a Windows Workgroup
From: http://scottiestech.info/2009/02/14/how-to-determine-the-master-browser-in-a-windows-workgroup/
Type "net view" and hit enter net view /domain to determine the list of workgroup names net view /domain:[WORKGROUP] to determine the list of puter names for each [WORKGROUP]
From: http://www.networksteve.com/forum/topic.php/Domain_computers_not_showing/?TopicId=23182&Posts=4
As James pointed out, XP/Server 2003 and WIN7/Server 2008 use different methods for this. XP/2003 do not understand the new network discovery method used in Windows 7. To see the whole network you have to rely on the computer browser service. This service is a legacy system from Windows NT and relies on Netbios names and LAN broadcasts. Win 7 and 2008 are backward compatible with the browser service. If something upsets the browser service (like shutting down or starting a master browser) it can take a while to settle down and a full browse list for the domain to be built.
From: http://support.microsoft.com/kb/188305
This article applies to a different version of Windows than the one you are using. Content in this article may not be relevant to you. Visit the Windows 7 Solution Center
Samba Boxes Taking Over As Master Browser For Win2k Domain
From: http://forum.soft32.com/linux/Samba-Boxes-Taking-Master-Browser-Win2k-Domain-ftopict356677.html
Edit the /etc/samba/smb.conf file and locate the line that reads.... ;local master = no and remove the semi-colon or add the line above without the semi-colon.
How to Determine the Master Browser in a Windows Workgroup
From: http://scottiestech.info/2009/02/14/how-to-determine-the-master-browser-in-a-windows-workgroup/
net view /domain
net view /domain:[WORKGROUP]
ping -n 1 -4 COMPUTER-NAME
nbtstat -A IP-ADDRESS
check for the _MSBROWSE_
first **net view /domain** to determine the list of workgroup names second **net view /domain:[WORKGROUP]** to determine the list of computer names for each [WORKGROUP] extracts the individual computer names and sticks them in an array iterates through the array and calls **ping -n 1 -4 COMPUTER-NAME** on each computer name (we only want to display IPv4 addresses, hence the “-4″ switch) iterates through the array of IP addresses and calls **nbtstat -A IP-ADDRESS** (the “-A” means “I’m giving you an IP address instead of a computer name”. This is a more reliable way of doing things.) After each call to nbtstat, it not only **checks for the _MSBROWSE_** string, but it also records the MAC address of the network adapter in the remote computer.
Script LANscan_v1.3.zip
nbtstat -A 192.168.1.1 nbtstat -A 192.168.1.2 nbtstat -A 192.168.1.3 nbtstat -A 192.168.1.4 nbtstat -A 192.168.1.5 nbtstat -A 192.168.1.7 nbtstat -A 192.168.1.8 nbtstat -A 192.168.1.10 nbtstat -A 192.168.1.12 nbtstat -A 192.168.1.16 nbtstat -A 192.168.1.17 nbtstat -A 192.168.1.18
browstat
browstat tickle \Device\NetBT_Tcpip_{F74DD27A-2662-4E1E-A3D1-3D0B5BC1F60C} workgroup
browstat elect \Device\NetBT_Tcpip_{F74DD27A-2662-4E1E-A3D1-3D0B5BC1F60C} workgroup \\graphics
You can download Browstat from either:
http://www.microsoft.com/downloads/details.aspx?FamilyId=49AE8576-9BB9-4126-9761-BA8011FABF38&displaylang=en http://support.microsoft.com/?id=188305
For more information about the browser subsystem (very intricate),see:
http://support.microsoft.com/?id=188305
http://support.microsoft.com/?id=188001
http://support.microsoft.com/?id=231312
http://support.microsoft.com/kb/q102878/
http://www.microsoft.com/technet/prodtechnol/winntas/deploy/prodspecs/ntbrowse.mspx
http://www.microsoft.com/technet/archive/win95/w95brows.mspx
SYMPTOMS: 1) After enabling ICS/ICF, you can't see any computes on My Network places. If you try, you may get “workgroup is not accessible”.
2) If you use the net view command, you may receive “System error 6118 has occurred. The list of servers for this workgroup is not currently available.” message.
Resolutions: 1) This behavior can occur if you enable the ICF that will closes the ports for file sharing by default. To open these ports, right-click the network connection that is firewall protected> Properties>Advanced>Settings>Service Tab>Add, Enter 127.0.0.1) for the required Internet Protocol (IP) number. Enter UDP ports from 135 through 139, and TCP ports from 135 through 139 one by one (the external and internal port numbers should be identical).
Read this whole thread for several clues:
http://www.broadbandreports.com/forum/remark,13450150
http://support.microsoft.com/kb/191611
http://technet.microsoft.com/en-us/library/cc959923.aspx
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Browser\Parameters\IsDomainMaster : ''Change the value of this subkey to TRUE'' HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Browser\Parameters\MaintainServerList : ''Change the value of this subkey to Auto, True, False''
So our plan now is to do the following in our lab and test further: Set PDC Emulator MaintainServerList=Yes, IsDomainMaster=Yes All other DC's, set MaintainServerList=Auto,IsDomainMaster=Auto All member servers and workstations, set MaintainServerList=No,IsDomainMaster=No
The plan of action you are following is ok. You can also set the parameteres as below Set PDC Emulator MaintainServerList=Yes, IsDomainMaster=True All other DC's, set MaintainServerList=Auto,IsDomainMaster=False All member servers and workstations, set MaintainServerList=Auto,IsDomainMaster=False Hope this helps Regards, Sandesh Dubey.
If servers are frequently shut down and restarted, consider placing a BDC if the number of segments is not large, or at minimum a Windows-based member server on each segment with the IsDomainMaster registry setting set to True. This will give the server an edge during elections in becoming the master browser for the segment.
Learn Linux, 302 (Mixed environments): NetBIOS and WINS Configuring Samba to serve names and manage browsing
From: http://www.ibm.com/developerworks/linux/library/l-lpic3-314-2/
- In this article, learn about these concepts:
- Windows Internet Name Service (WINS)
- Network input/output system (NetBIOS)
- Local master browser features
- Domain master browser features
- Name resolution
- Configuring and using Samba as a WINS/NetBIOS Name Server (NBNS)
- NetBIOS browsing, elections, and service announcements
Samba Book: http://www.samba.org/samba/docs/using_samba/ch07.html
Microsoft Description of Master Browser: http://www.microsoft.com/resources/documentation/windowsnt/4/server/reskit/en-us/net/chptr3.mspx?mfr=true
Mac Server
From: http://www.mactech.com/articles/mactech/Vol.23/23.10/DemystifyingWindowsnetworkbrowsing/index.html
“Mac OS X Server can also provide network browsing service as a workgroup master browser or a Windows domain master browser for Windows clients. A workgroup master browser enables Windows computers to discover servers on one subnet. A domain master browser enables Windows computers to discover servers across subnets.”