VPN not working. Unable to negotiate phase 1 and error at port 500

[ctvi]

6d21h: ISAKMP0:0:N/A:0):incrementing error counter on sa: retransmit phase 1
6d21h: ISAKMP0:0:N/A:0): retransmitting phase 1 MM_NO_STATE
6d21h: ISAKMP0:0:N/A:0): sending packet to NNN.NNN.NNN.NNN my_port 500 peer_port 500 (I) MM_NO_STATE

Any help?

NNN.NNN.NNN.NNN=my public ip address

 

[NettableWalker]

I need a LOT more info than that.

Post a config.

MCP,CCA, Net+, 1 quarter CCNP...

 

[KiscoKid]

As previous poster says, post your config. It's either an IKE failure or some firewall issue. Please confirm if there are any firewalls between the 2 endpoints and whether they've been configured to allow the standard VPN ports through.