how much does vpn cause BW degradation
The difference will be so small (a few percent) that your users will not notice any change (which is the real factor, not any theoretical overhead). Most likely the wireless link is the slow point in the network, and this will only add a little extra. If you have Cisco (not sure why you want [...]
View Answer
| July 25, 2009 8:25 PM
Bandwidth, BW, Degradation, VPN
The difference will be so small (a few percent) that your users will not notice any change (which is the real factor, not any theoretical overhead). Most likely the wireless link is the slow point in the network, and this will only add a little extra. If you have Cisco (not sure why you want [...]
View Answer
| July 25, 2009 8:25 PM
Bandwidth, BW, Degradation, VPN
cisco command
<b>show arp</b> will show you the IP address and mac address of any network device that has sent data to or from the router, but there is no command to show the serial number of a PC on the network from a Cisco device, this is not possible. The CDP command only works with Cisco [...]
View Answer
| July 25, 2009 8:18 PM
Cisco, Cisco Command, Network management
<b>show arp</b> will show you the IP address and mac address of any network device that has sent data to or from the router, but there is no command to show the serial number of a PC on the network from a Cisco device, this is not possible. The CDP command only works with Cisco [...]
View Answer
| July 25, 2009 8:18 PM
Cisco, Cisco Command, Network management
NIC Bridging
About the only time you should team or bridge in a virtual machine is if you are joining virtual networks together within the same physical host. The only application I’ve ever run across in my 8+ years of experience with virtualization, is in the case of a firewall/proxy host, isolating certain VMs at the network [...]
View Answer
| July 25, 2009 12:59 AM
NIC, Virtual Machines, VM guest bridging, VMware, VMware ESXi
About the only time you should team or bridge in a virtual machine is if you are joining virtual networks together within the same physical host. The only application I’ve ever run across in my 8+ years of experience with virtualization, is in the case of a firewall/proxy host, isolating certain VMs at the network [...]
View Answer
| July 25, 2009 12:59 AM
NIC, Virtual Machines, VM guest bridging, VMware, VMware ESXi
the time taken for a file to be transferred
This <a href=”http://www.packet-level.net/2006TechNet/latency_throughput_RTT_calculations.pdf”>presentation from Laura Chappell</a> (the Bitgirl) will help you work through this calculation.
View Answer
| July 24, 2009 5:48 PM
Broadband speed, Network speed
This <a href=”http://www.packet-level.net/2006TechNet/latency_throughput_RTT_calculations.pdf”>presentation from Laura Chappell</a> (the Bitgirl) will help you work through this calculation.
View Answer
| July 24, 2009 5:48 PM
Broadband speed, Network speed
new to IT looking to improve & make career in networking
The <a href=”http://www.comptia.org/certifications/listed/network.aspx”>Comptia Network+ certification</a> is a good baseline for network knowledge. As others say here, nothing can replace experience. So practice networking on your own network or volunteer for some organization needing assistance with theirs.
View Answer
| July 24, 2009 5:27 PM
IT careers, Network administration, Networking careers, Systems administration
The <a href=”http://www.comptia.org/certifications/listed/network.aspx”>Comptia Network+ certification</a> is a good baseline for network knowledge. As others say here, nothing can replace experience. So practice networking on your own network or volunteer for some organization needing assistance with theirs.
View Answer
| July 24, 2009 5:27 PM
IT careers, Network administration, Networking careers, Systems administration
difference between l2 and l3 VPN
See if this <a href=”http://www.marketclarity.com.au/freebies/DemystifyingLayer2andLayer3VPNs.pdf”>document from an Australian telecom research firm</a> answers your question. Another good source might be the <a href=”http://www.vpnc.org/vpn-standards.html”>VPN Consortium website</a>.
View Answer
| July 24, 2009 11:41 AM
MPLS VPN, VPN
See if this <a href=”http://www.marketclarity.com.au/freebies/DemystifyingLayer2andLayer3VPNs.pdf”>document from an Australian telecom research firm</a> answers your question. Another good source might be the <a href=”http://www.vpnc.org/vpn-standards.html”>VPN Consortium website</a>.
View Answer
| July 24, 2009 11:41 AM
MPLS VPN, VPN
How can i build a gateway
The following link should help you setup your Gateway http://www.homenetworkhelp.info/index.php?pg=articles-install-simple-network-gateway&mn=a
View Answer
| July 23, 2009 9:23 PM
Exchange, Gateways
The following link should help you setup your Gateway http://www.homenetworkhelp.info/index.php?pg=articles-install-simple-network-gateway&mn=a
View Answer
| July 23, 2009 9:23 PM
Exchange, Gateways
Problem bridging nics that have been teamed on ESXI 4.0
While you haven’t given all of the requisite information to formulate a complete answer, I think I see enough to be able to respond. The short answer: Don’t bridge in the guest OS, unless you have two virtual NICs that go to two different vswitches in ESX. If you’ve done what I think you’ve done, [...]
View Answer
| July 23, 2009 1:50 PM
NIC, VMware, VMware ESXi, VMware ESXI 4.0 Performance
While you haven’t given all of the requisite information to formulate a complete answer, I think I see enough to be able to respond. The short answer: Don’t bridge in the guest OS, unless you have two virtual NICs that go to two different vswitches in ESX. If you’ve done what I think you’ve done, [...]
View Answer
| July 23, 2009 1:50 PM
NIC, VMware, VMware ESXi, VMware ESXI 4.0 Performance
110 block cross connections
If you are talking about 110 punch down blocks and rewiring them then the answer is once. if you need to rewire a 110 block then you must be very careful to remove the existing connections without damaging the blades. you can get 2 or 3 reconnects ( punch downs) before you start getting unacceptable [...]
View Answer
| November 9, 2012 4:57 PM
Ethernet, wires
If you are talking about 110 punch down blocks and rewiring them then the answer is once. if you need to rewire a 110 block then you must be very careful to remove the existing connections without damaging the blades. you can get 2 or 3 reconnects ( punch downs) before you start getting unacceptable [...]
View Answer
| November 9, 2012 4:57 PM
Ethernet, wires
Network Connection Gone Windows Server 2003
Can you restart the server in safe mode with networking? Do services work there? If not, sounds like your system is beyond repair and will need to be reinstalled. Were there any critical services like DHCP, DNS running on this system and not mirrored on the other DC? If so, you need to find a [...]
View Answer
| July 22, 2009 4:54 PM
LAN, Network Connection lost, Network connectivity, Windows Server 2003
Can you restart the server in safe mode with networking? Do services work there? If not, sounds like your system is beyond repair and will need to be reinstalled. Were there any critical services like DHCP, DNS running on this system and not mirrored on the other DC? If so, you need to find a [...]
View Answer
| July 22, 2009 4:54 PM
LAN, Network Connection lost, Network connectivity, Windows Server 2003
wireless roaming howto
You need to configure the other two as just access points, not routers. Then connect the three together on the wired network side. The wireless and wired networks that connect them to the trendnet near the proxy, need to be layer 2 bridged together. Then confirm that you can connect to each one on the [...]
View Answer
| July 22, 2009 6:55 AM
Access Points, Router configuration, Routers, Wireless routers
You need to configure the other two as just access points, not routers. Then connect the three together on the wired network side. The wireless and wired networks that connect them to the trendnet near the proxy, need to be layer 2 bridged together. Then confirm that you can connect to each one on the [...]
View Answer
| July 22, 2009 6:55 AM
Access Points, Router configuration, Routers, Wireless routers
Microsoft Outlook and VPN Clients
Firstly, I presume they can access other hosts on the Corporate network using the Cisco client ? There is no configuration of the Cisco client by the user, other than the address and password (pre-shared-key) to connect to the VPN device, which can be a router, firewall or concentrator. It is on the VPN device [...]
View Answer
| July 22, 2009 6:22 AM
Cisco VPN, Outlook 2003, VPN, VPN Error Messages
Firstly, I presume they can access other hosts on the Corporate network using the Cisco client ? There is no configuration of the Cisco client by the user, other than the address and password (pre-shared-key) to connect to the VPN device, which can be a router, firewall or concentrator. It is on the VPN device [...]
View Answer
| July 22, 2009 6:22 AM
Cisco VPN, Outlook 2003, VPN, VPN Error Messages
bandwidth manager
There is no easy method to control bandwidth utilization on this home-based router. While you can limit access for certain applications, there is no method to limit usage of standard web traffic. I suggest you use a freeware sniffer (Microsoft Network Monitor is an easy one to download and use) to determine the type of [...]
View Answer
| July 21, 2009 8:58 PM
bandwidth allocation, Bandwidth limits, Bandwidth management, Linksys WRT54GR, Routers, Wireless routers
There is no easy method to control bandwidth utilization on this home-based router. While you can limit access for certain applications, there is no method to limit usage of standard web traffic. I suggest you use a freeware sniffer (Microsoft Network Monitor is an easy one to download and use) to determine the type of [...]
View Answer
| July 21, 2009 8:58 PM
bandwidth allocation, Bandwidth limits, Bandwidth management, Linksys WRT54GR, Routers, Wireless routers
File deletion on the network
You didn’t mention what operating system this is for but assuming it is MS Windows, you should look into <a href=”http://technet.microsoft.com/en-us/library/cc785914(WS.10).aspx”>Microsoft Volume Shadow Copies</a> and how they work in the Windows server & client environment. Check out this <a href=”http://lmgtfy.com/?q=volume+shadow+copies”>Google search</a> for more information.
View Answer
| July 21, 2009 8:22 PM
Network administration, Network security, Security management
You didn’t mention what operating system this is for but assuming it is MS Windows, you should look into <a href=”http://technet.microsoft.com/en-us/library/cc785914(WS.10).aspx”>Microsoft Volume Shadow Copies</a> and how they work in the Windows server & client environment. Check out this <a href=”http://lmgtfy.com/?q=volume+shadow+copies”>Google search</a> for more information.
View Answer
| July 21, 2009 8:22 PM
Network administration, Network security, Security management
what is rack awareness of HDFS?
“…Large HDFS instances run on a cluster of computers that commonly spread across many racks. Communication between two nodes in different racks has to go through switches. In most cases, network bandwidth between machines in the same rack is greater than network bandwidth between machines in different racks…”. The idea is that the rack id [...]
View Answer
| July 21, 2009 8:18 PM
Database optimization, HDFS, Network performance, Rack Awareness
“…Large HDFS instances run on a cluster of computers that commonly spread across many racks. Communication between two nodes in different racks has to go through switches. In most cases, network bandwidth between machines in the same rack is greater than network bandwidth between machines in different racks…”. The idea is that the rack id [...]
View Answer
| July 21, 2009 8:18 PM
Database optimization, HDFS, Network performance, Rack Awareness
What is HDFS file sytem namespace.
The HDFS (Hadoop Distributed File System) filesystem is a Java-based filesystem, which stores large files (an ideal file size is a multiple of 64 MB[8]), across multiple machines. It achieves reliability by replicating the data across multiple hosts. For more information, have a look at <a href=”http://hadoop.apache.org/common/docs/current/hdfs_design.html”>the official documentation</a>
View Answer
| July 21, 2009 8:07 PM
Distributed File System, HDFS
The HDFS (Hadoop Distributed File System) filesystem is a Java-based filesystem, which stores large files (an ideal file size is a multiple of 64 MB[8]), across multiple machines. It achieves reliability by replicating the data across multiple hosts. For more information, have a look at <a href=”http://hadoop.apache.org/common/docs/current/hdfs_design.html”>the official documentation</a>
View Answer
| July 21, 2009 8:07 PM
Distributed File System, HDFS
Half duplex vs full duplex
Kechild, At some point an engineer may have set the speed and/or duplex setting to ‘auto negotiate’ (depends on your vendor). With most cards we use, changes to these settings will not take place until the card is disabled and then re-enabled, as would happen after a reboot. A change to the configuration could easily [...]
View Answer
| July 21, 2009 6:38 PM
Full Duplex, Half Duplex, Network Interface Cards, NFS, NFS Storage, RAID
Kechild, At some point an engineer may have set the speed and/or duplex setting to ‘auto negotiate’ (depends on your vendor). With most cards we use, changes to these settings will not take place until the card is disabled and then re-enabled, as would happen after a reboot. A change to the configuration could easily [...]
View Answer
| July 21, 2009 6:38 PM
Full Duplex, Half Duplex, Network Interface Cards, NFS, NFS Storage, RAID
Envelope printer & document printer
I’m afraid can’t be done, only one default printer on set under windows. Try this out If the printer is on a print server or has an IP you could Add a printer (you can do it either on the print server, if you have one, or on each machine) Add a Local Printer(uncheck automatically [...]
View Answer
| July 21, 2009 6:03 PM
LAN, LAN Printers, Printers, Printing
I’m afraid can’t be done, only one default printer on set under windows. Try this out If the printer is on a print server or has an IP you could Add a printer (you can do it either on the print server, if you have one, or on each machine) Add a Local Printer(uncheck automatically [...]
View Answer
| July 21, 2009 6:03 PM
LAN, LAN Printers, Printers, Printing
Cisco ASA5510
You can reboot it with the <b>reload</b> command, but I don’t think you can power it off remotely. If you want to stop anyone using it, then shutdown the interfaces, except the one you need to use to access it for command purposes. Or you could shut that one down as well, then you need [...]
View Answer
| July 21, 2009 4:41 PM
Cisco, Cisco ASA5510, Firewalls, PIX
You can reboot it with the <b>reload</b> command, but I don’t think you can power it off remotely. If you want to stop anyone using it, then shutdown the interfaces, except the one you need to use to access it for command purposes. Or you could shut that one down as well, then you need [...]
View Answer
| July 21, 2009 4:41 PM
Cisco, Cisco ASA5510, Firewalls, PIX
Well Im stumped about these Access points
Sorry, but I am struggleing to understand exactly what you have done, or are trying to do. However, the following are assumptions, based on what you have posted, and on the technology in general. The APs are usually layer 2 devices. The static IP for the AP is usually for management only. Every AP will [...]
View Answer
| July 21, 2009 4:31 PM
Wireless Access Points, Wireless networking, Wireless networks
Sorry, but I am struggleing to understand exactly what you have done, or are trying to do. However, the following are assumptions, based on what you have posted, and on the technology in general. The APs are usually layer 2 devices. The static IP for the AP is usually for management only. Every AP will [...]
View Answer
| July 21, 2009 4:31 PM
Wireless Access Points, Wireless networking, Wireless networks
