windows 7 DisableDHCPMediaSense and routing table
On xp, if DisableDHCPMediaSense is set to 1 (true), I unplug the NIC cable, the routing table would remain the same before and after.
On windows 7 (and server 2008, and vista), I do the same thing but the entries for this networking adapter interface would disappear from the routing table.
It seems to me that windows still could detect the disconnection and update the routing table.
What else could I do to keep the routing table the same even the cable is unplugged on windows 7 (server 2008, vista)?
BTW 10.4.0.6 is the static IP of the NIC interface.
C:\Users\xxx>netsh interface ipv4 show
Querying active state...General Global Parameters
---------------------------------------------
Default Hop Limit : 128 hops
Neighbor Cache Limit : 256 entr
Route Cache Limit : 128 entr
Reassembly Limit : 16489536
ICMP Redirects : enabled
Source Routing Behavior : forward
Task Offload : enabled
Dhcp Media Sense : disabled <-------------------
Media Sense Logging : enabled
MLD Level : all
MLD Version : version3
Multicast Forwarding : disabled
Group Forwarded Fragments : disabled
Randomize Identifiers : enabled
Address Mask Reply : disabledCurrent Global Statistics
---------------------------------------------
Number of Compartments : 1
Number of NL clients : 5
Number of FL providers : 4
before:
C:\Users\xxx>route print
===========================================================================
Interface List
11 ...00 10 18 3a 8b ec ...... Broadcom NetXtreme Gigabit Ethernet
10 ...00 23 ae 6a 03 90 ...... Intel(R) 82566DM-2 Gigabit Network Connectio
1 ........................... Software Loopback Interface 1
===========================================================================IPv4 Route Table
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 155.177.16.1 155.177.16.85 20
10.4.0.0 255.254.0.0 On-link 10.4.0.6 276 <---- will disappear
10.4.0.6 255.255.255.255 On-link 10.4.0.6 276 <---- will disappear
10.5.255.255 255.255.255.255 On-link 10.4.0.6 276
127.0.0.0 255.0.0.0 On-link 127.0.0.1 306
127.0.0.1 255.255.255.255 On-link 127.0.0.1 306
127.255.255.255 255.255.255.255 On-link 127.0.0.1 306
155.177.16.0 255.255.255.0 On-link 155.177.16.85 276
155.177.16.85 255.255.255.255 On-link 155.177.16.85 276
155.177.16.255 255.255.255.255 On-link 155.177.16.85 276
224.0.0.0 240.0.0.0 On-link 127.0.0.1 306
224.0.0.0 240.0.0.0 On-link 10.4.0.6 276
224.0.0.0 240.0.0.0 On-link 155.177.16.85 276
255.255.255.255 255.255.255.255 On-link 127.0.0.1 306
255.255.255.255 255.255.255.255 On-link 10.4.0.6 276
255.255.255.255 255.255.255.255 On-link 155.177.16.85 276
===========================================================================
Persistent Routes:
NoneIPv6 Route Table
===========================================================================
Active Routes:
If Metric Network Destination Gateway
1 306 ::1/128 On-link
1 306 ff00::/8 On-link
===========================================================================
Persistent Routes:
None
After:
C:\Users\xxx>route print
===========================================================================
Interface List
11 ...00 10 18 3a 8b ec ...... Broadcom NetXtreme Gigabit Ethernet
10 ...00 23 ae 6a 03 90 ...... Intel(R) 82566DM-2 Gigabit Network Connectio
1 ........................... Software Loopback Interface 1
===========================================================================IPv4 Route Table
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 155.177.16.1 155.177.16.85 20
127.0.0.0 255.0.0.0 On-link 127.0.0.1 306
127.0.0.1 255.255.255.255 On-link 127.0.0.1 306
127.255.255.255 255.255.255.255 On-link 127.0.0.1 306
155.177.16.0 255.255.255.0 On-link 155.177.16.85 276
155.177.16.85 255.255.255.255 On-link 155.177.16.85 276
155.177.16.255 255.255.255.255 On-link 155.177.16.85 276
224.0.0.0 240.0.0.0 On-link 127.0.0.1 306
224.0.0.0 240.0.0.0 On-link 155.177.16.85 276
255.255.255.255 255.255.255.255 On-link 127.0.0.1 306
255.255.255.255 255.255.255.255 On-link 155.177.16.85 276
===========================================================================
Persistent Routes:
NoneIPv6 Route Table
===========================================================================
Active Routes:
If Metric Network Destination Gateway
1 306 ::1/128 On-link
1 306 ff00::/8 On-link
===========================================================================
Persistent Routes:
None
Thanks.
Answers
- I have see some other samples. We will report it to proper department.
Arthur Xie - MSFT- Marked As Answer byArthur XieMSFT, ModeratorMonday, November 16, 2009 4:08 AM
All Replies
Did you restart the computer after disconnect one connection? How does it work if you plug the cable again? How does it work if you disconnect the remained connection?
If DisableDHCPMediaSense works, the route table will not change if the computer does not restart.
Arthur Xie - MSFT- I did not restart the computer after disconnect one connection. If I plug the cable again, the missing entries come back to the routing table.
I could not disconnect the remained connection since the machine is in the corporate domain and will be stuck there without connection.
You could see from the cli "netsh interface ipv4 show" that DisableDHCPMediaSense is disabled. The behavior on xp is as you described, the route table will not change if the computer does not restart. However, vista or 7 changes the behavior and this flag no longer functions like it's on xp.
Any other flag I could use on vista or 7?
Thanks. - I have see some other samples. We will report it to proper department.
Arthur Xie - MSFT- Marked As Answer byArthur XieMSFT, ModeratorMonday, November 16, 2009 4:08 AM
