VPN to remote network on same subnet as local network

Symptoms: 
You need to connect using VPN connection to remote client site and realize that you both using same IP subnet. You connect fine but can't access any resources on the remote subnet. Some people may suggest you to change one of the subnet, but you can't do that because both of subnet are office environment.


Cause:
It's network and route thing. Your PC think the remote IP is locally.


Solution:
You need to manually add routing for remote IP at your PC. You can do that using command ROUTE.
1. Connect to VPN site.


2. From command prompt run ROUTE PRINT to show status. In my case:

===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x2 ...00 11 09 26 33 75 ...... VIA Rhine II Fast Ethernet Adapter - Packet Scheduler Miniport
0x60004 ...00 53 45 00 00 00 ...... WAN (PPP/SLIP) Interface
===========================================================================
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0       10.10.10.1      10.10.10.9  21
          0.0.0.0          0.0.0.0      10.10.10.79     10.10.10.79  1
        10.10.8.0    255.255.252.0       10.10.10.9      10.10.10.9  20
       10.10.10.9  255.255.255.255        127.0.0.1       127.0.0.1  20
      10.10.10.79  255.255.255.255        127.0.0.1       127.0.0.1  50
   10.255.255.255  255.255.255.255       10.10.10.9      10.10.10.9  20
   10.255.255.255  255.255.255.255      10.10.10.79     10.10.10.79  50
        127.0.0.0        255.0.0.0        127.0.0.1       127.0.0.1  1
  2xx.2xx.2xx.2xx  255.255.255.255       10.10.10.1      10.10.10.9  20
        224.0.0.0        240.0.0.0       10.10.10.9      10.10.10.9  20
        224.0.0.0        240.0.0.0      10.10.10.79     10.10.10.79  1
  255.255.255.255  255.255.255.255       10.10.10.9      10.10.10.9  1
  255.255.255.255  255.255.255.255      10.10.10.79     10.10.10.79  1
Default Gateway:       10.10.10.79
===========================================================================
Persistent Routes:
  None

3. From here, we get information:

   - 10.10.10.9      my current IP

   - 10.10.10.79     my assigned VPN IP

   - 0x60004               my VPN interface

   - 2xx.2xx.2xx.2xx  I need to hide my client public IP

4. To manually add route run:

ROUTE ADD <TargetIP> MASK <Mask> <GatewayIP> METRIC <Metric> IF <InterfaceID>

so for my case if I want to add route to single IP 10.10.10.18 on remote site:

ROUTE ADD 10.10.10.18 MASK 255.255.255.255 10.10.10.79 METRIC 1 IF 0x6004

5. Run ROUTE PRINT again to make sure the new route listed

===========================================================================

Interface List

0x1 ........................... MS TCP Loopback interface

0x2 ...00 11 09 26 33 75 ...... VIA Rhine II Fast Ethernet Adapter - Packet Scheduler Miniport

0x60004 ...00 53 45 00 00 00 ...... WAN (PPP/SLIP) Interface

===========================================================================

===========================================================================

Active Routes:

Network Destination        Netmask          Gateway       Interface  Metric

          0.0.0.0          0.0.0.0       10.10.10.1      10.10.10.9  21

          0.0.0.0          0.0.0.0      10.10.10.79     10.10.10.79  1

        10.10.8.0    255.255.252.0       10.10.10.9      10.10.10.9  20

       10.10.10.9  255.255.255.255        127.0.0.1       127.0.0.1  20

      10.10.10.18  255.255.255.255      10.10.10.79     10.10.10.79  1

      10.10.10.79  255.255.255.255        127.0.0.1       127.0.0.1  50

   10.255.255.255  255.255.255.255       10.10.10.9      10.10.10.9  20

   10.255.255.255  255.255.255.255      10.10.10.79     10.10.10.79  50

        127.0.0.0        255.0.0.0        127.0.0.1       127.0.0.1  1

  2xx.2xx.2xx.2xx  255.255.255.255       10.10.10.1      10.10.10.9  20

        224.0.0.0        240.0.0.0       10.10.10.9      10.10.10.9  20

        224.0.0.0        240.0.0.0      10.10.10.79     10.10.10.79  1

  255.255.255.255  255.255.255.255       10.10.10.9      10.10.10.9  1

  255.255.255.255  255.255.255.255      10.10.10.79     10.10.10.79  1

Default Gateway:       10.10.10.79

===========================================================================

Persistent Routes:

  None

Or You can use Portable GUI Application NetRouteView from nirsoft.net to show and manipulating your windows routing table.

WRT54G v5 Management Mode to recover the router by uploading a new firmware image

Symptoms:
If you encounter an irrecoverable condition with the WRT54G v5, you can use Management Mode to recover the router by uploading a new firmware image. In Management Mode, the router will have just enough functionality to load a newer firmware. You should be able to recover the router is most situations.

Solution:
1: Unplug the power cord from the back of the router.
2: Hold down the Reset button.
3: While holding down the Reset button, plug back in the power cord to the router.
4: Continue to hold the Reset button for five (5) seconds. After five (5) seconds, release the button.
5: Wait for about one (1) minute.
6: Type in the router's IP address of http://192.168.1.1 into the Address field and press the [Enter] key on your wired connected computer Browser.
7: The Management Mode - Firmware Upgrade interface should appear.
NOTE: If you accidentally enter into Management Mode, you can exit by simply unplugging the power cord from the router and by plugging it back in.
8: Click Browse and locate the firmware file.
9: Click Apply to start the firmware upgrade process.
10: Once the firmware upgrade process has successfully completed, an "Upgrade Success" message will appear to confirm that the upgrade has ended.
11:Unplug the power cord from the back of the router and plug it back in -- this will restart your router using the new firmware.


More Info: http://linksys.custhelp.com/cgi-bin/linksys.cfg/php/enduser/std_adp.php?p_faqid=3176&p_created=1131055153&p_sid=Yy2tOZTh&p_lva=&p_sp=cF9zcmNoPSZwX3NvcnRfYnk9JnBfZ3JpZHNvcnQ9JnBfcm93X2NudD0xMzMzJnBfcHJvZHM9JnBfY2F0cz0mcF9wdj0mcF9jdj0mcF9zZWFyY2hfdHlwZT1hbnN3ZXJzLnNlYXJjaF9ubCZwX3BhZ2U9MQ**&p_li=&p_topview=1