I have the following topology.
1. My WAN router ADSL port is connected toa ISP,and the LAN interface is connected to a Manageable Layer 2 switch (VLAN 10 name public) with the a public IP address 202.X.X.201/29,then my ASA5510 outside interface is connected to the same mageable swiitch (VLAN 10 name public) with the public IP address 202.X.X.202/29,then my Nortel VPN router public interfcae also connected to the same manageable Layer 2 witch (VLAN 10 name publis)with an IP address 202.X.X.203/29.In both ASA and Nortel VPN router default gateway is pointing to WAN router IP address 202.X.X.201.
Then my ASA inside interface and nortel VPN router private interface is connected to the same mageable layer 2 switch (VLAN 20 name inside) with an IP address 172.20.0.1 and 172.20.0.2 respectively.
In this case all the local users goes to internet t hrough ASA5510.All remote users will communicate to inside servers through remote IPSec VPNa and SSLVPN through Nortel VPN router.
Here in this case I am not able to ping the WAN router,or any outside DNS from ASA5510 prompt,where as I am able to ping from the Nortel VPN router .
Now at this stage if I change the default gateway to Nortel router that is instead of
route outeside 0.0.0.0 0.0.0.0 202.X.X.201 if I changed to route outside 0.0.0.0 0.0.0.0 202.X.X.203 which is the Nortel VPN router .Then I am able to reach WAN router pinging,and all other public DNS from ASA5510 through Nortel VPN router.
Waht could be the possible cause.