Thursday, July 25, 2019

Enterprise networking for Chrome devices

Enterprise networking for Chrome devices

When deploying Chrome devices in a business or school, you can set up a wireless network much the same way you would set up an office or classroom full of laptops or tablets. You want to make sure that you have the following:
  • Good wireless coverage
  • Sufficient Internet bandwidth
  • Wireless access points that can handle the number of devices you want to connect.

Recommended networking configuration

SettingRecommendation
Wi-Fi802.11n 5 GHz. Use non-DFS channels when possible.  See 5 GHz channels for a table of non-DFS channels in your country. In the USA, those are channels 36-48 and 149-165.  
BandwidthAt least .2-.5 Mbps per user in a typical deployment. Latency should be less than 100ms when pinging Google's public DNS server at 8.8.8.8. For HD video streaming and HD Hangouts, at least 1 Mbps, preferably 2-5 Mbps or greater per user.
Access points30 devices per access point. Enterprise-grade access points can handle more. Please refer to the product’s documentation.
Policy Refresh RateYou can specify between 30 to 1440 minutes as the interval for the Chrome device(s) to sync new policies from the Admin console.
See below for more information about the items in the table.

Access point(s)

The access point should support Wi-Fi 802.11a/g/n. Google recommends 5 GHz 802.11n connections with WPA2-PSK encryption.
  • For small deployments of under 30 devices, consumer-grade networking equipment is sufficient.
  • For deployments greater than 30 devices or involving multiple rooms, enterprise-grade, centrally managed networking equipment is recommended.
Because of the high density of laptops in a classroom or workplace, network design is important. If you use multiple Wi-Fi access points in a small space, avoid using overlapping Wi-Fi channels to prevent interference. You can test your Wi-Fi strength and coverage using the Wi-Fi Analyzer Android app.

Bandwidth considerations

The amount of network bandwidth you need depends on how the Chrome devices will be used. For general web browsing and editing Google Drive documents, 0.2-0.5 Mbps per concurrent session at a minimum should provide satisfactory performance.
If your employees or students will be streaming video or using Google+ Hangouts, at least 1 Mbps per concurrent user session is needed and >4 Mbps is required for HD video streaming.
Latency may be a greater indicator of user perception of performance than bandwidth for interactive web-based applications.  Generally, <100 ms ping is needed for a good experience.
Note: See Set up TLS (or SSL) inspection on Chrome devices for information on how to set up networks with TLS and SSL content filters.

What are the maximum number of HTTP connections I can make with a Chrome device or browser?

  • The maximum number of connections per proxy is 32 connections. For more details, see the Chromium site.
  • Maximum per Host: 6 connections
  • Total HTTP pooled connections per browser: 256 connections
  • You can also verify what the limits are by going to chrome://net-internals/#sockets. You'll see a column titled Max Per Group which indicates the connection per host limit.

Tuesday, July 23, 2019

Recovery Global catalog in win 2003 server with ntdsutil

Active directory recovery windows 2003 server

*Global catalag error.

1. dcdiag /v
Starting test: FsmoCheck
   Warning: DcGetDcName(GC_SERVER_REQUIRED) call failed, error 1355
   A Global Catalog Server could not be located - All GC's are down.
   Warning: DcGetDcName(PDC_REQUIRED) call failed, error 1355
   A Primary Domain Controller could not be located.
   The server holding the PDC role is down.
   Warning: DcGetDcName(TIME_SERVER) call failed, error 1355
   A Time Server could not be located.
   The server holding the PDC role is down.
   Preferred Time Server Name: \\iics-ads.ipeka.net
   Locator Flags: 0xe00003e5
   Warning: DcGetDcName(KDC_REQUIRED) call failed, error 1355
   A KDC could not be located - All the KDCs are down.

2. nltest.exe /dsregdns
3. ntdsutil
4. ntdsutil: roles
5. fsmo maintenance: connection
server connections: connect to server iics-fm
Binding to iics-fm ...
DsBindW error 0x6ba(The RPC server is unavailable.)
6. server connections: connect to server iics-ads
Binding to iics-ads ...
Connected to iics-ads using credentials of locally logged on user.
server connections: q

7. fsmo maintenance: seize infrastructure master
Attempting safe transfer of infrastructure FSMO before seizure.
FSMO transferred successfully - seizure not required.
Server "iics-ads" knows about 5 roles
Schema - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,
CN=Configuration,DC=ipeka,DC=net
Domain - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,
CN=Configuration,DC=ipeka,DC=net
PDC - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,CN=
Configuration,DC=ipeka,DC=net
RID - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,CN=
Configuration,DC=ipeka,DC=net
Infrastructure - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,C
N=Sites,CN=Configuration,DC=ipeka,DC=net

8. fsmo maintenance: seize pdc
Attempting safe transfer of PDC FSMO before seizure.
FSMO transferred successfully - seizure not required.
Server "iics-ads" knows about 5 roles
Schema - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,
CN=Configuration,DC=ipeka,DC=net
Domain - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,
CN=Configuration,DC=ipeka,DC=net
PDC - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,CN=
Configuration,DC=ipeka,DC=net
RID - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,CN=
Configuration,DC=ipeka,DC=net
Infrastructure - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,C
N=Sites,CN=Configuration,DC=ipeka,DC=net

9. fsmo maintenance: seize rid master
The Selected Server is already the RID role owner

10. fsmo maintenance: seize schema master
Attempting safe transfer of schema FSMO before seizure.
FSMO transferred successfully - seizure not required.
Server "iics-ads" knows about 5 roles
Schema - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,
CN=Configuration,DC=ipeka,DC=net
Domain - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,
CN=Configuration,DC=ipeka,DC=net
PDC - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,CN=
Configuration,DC=ipeka,DC=net
RID - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,CN=
Configuration,DC=ipeka,DC=net
Infrastructure - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,C
N=Sites,CN=Configuration,DC=ipeka,DC=net

11. fsmo maintenance: seize domain naming master
Attempting safe transfer of domain naming FSMO before seizure.
FSMO transferred successfully - seizure not required.
Server "iics-ads" knows about 5 roles
Schema - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,
CN=Configuration,DC=ipeka,DC=net
Domain - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,
CN=Configuration,DC=ipeka,DC=net
PDC - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,CN=
Configuration,DC=ipeka,DC=net
RID - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,CN=Sites,CN=
Configuration,DC=ipeka,DC=net
Infrastructure - CN=NTDS Settings,CN=IICS-ADS,CN=Servers,CN=Default-First-Site,C
N=Sites,CN=Configuration,DC=ipeka,DC=net

12. fsmo maintenance: q

13. ntdsutil: q
       Disconnecting from iics-ads...


RESULT:
C:\Program Files\Support Tools>netdom query fsmo
Schema owner                iics-ads.ipeka.net

Domain role owner           iics-ads.ipeka.net

PDC role                    iics-ads.ipeka.net

RID pool manager            iics-ads.ipeka.net

Infrastructure owner        iics-ads.ipeka.net

The command completed successfully.



Remove old server from domain controller without DCpromo.

C:\Program Files\Support Tools>ntdsutil

1. ntdsutil: metadata cleanup
2. metadata cleanup: connection
3. server connections: connect to server iics-ads
Binding to iics-ads ...
Connected to iics-ads using credentials of locally logged on user.
server connections: select operation target
4. server connections: q
5. metadata cleanup: select operation target
6. select operation target: list domains
Found 1 domain(s)
0 - DC=ipeka,DC=net
select operation target: select domain 0
No current site
Domain - DC=ipeka,DC=net
No current server
No current Naming Context
select operation target: list sites
Found 1 site(s)
0 - CN=Default-First-Site,CN=Sites,CN=Configuration,DC=ipeka,DC=net

7. select operation target: list servers in site
No current site
No current site
Domain - DC=ipeka,DC=net
No current server
No current Naming Context

8. select operation target: list sites
Found 1 site(s)
0 - CN=Default-First-Site,CN=Sites,CN=Configuration,DC=ipeka,DC=net

9. select operation target: list servers in sites
No current site
No current site
Domain - DC=ipeka,DC=net
No current server
No current Naming Context

10.metadata cleanup: q
11. ntdsutil: q
Disconnecting from iics-ads...