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New Member

Cisco vpn client 4.8 connects but cannot send or receive

I am using a cisco 2811 running the easy vpn server. I have two

clients located in different states with different isp's who can

connect but cannot send or recieve. One client in florida was able to

access everything for months after system was set up then suddenly it

just stoped working. No changes were made to software or hardware on

2811. When i attempt to test the connection myself it always works.

The other client in DC was able to connect before going to DC. They

both have diffent isp's both are high speed connections. Anyone have

an idea.

Thanks,

  • Other Security Subjects
5 REPLIES
Silver

Re: Cisco vpn client 4.8 connects but cannot send or receive

Try this:

1. Connect with the client then do a "show crypto ispec sa" on the router. Find the SA

assigned to you ( it will show the ip address that you were assigned to from the pool ).

In there you will see "encrypts" and "decrypts" .

Assuming you see decrypts but no encrypts, the problem is either going to be with NAT or

with the network not knowing where to route traffic destined for the network you specified

in the vpn Pool.

2. Check and make sure NAT 0 is setup to bypass traffic between the LAN network and the

VPN client pool network.

3. Verify the local Lan knows to send traffic destined for the VPN pool to the Router.

4. check port no udp 500 is allowed or not

Gold

Re: Cisco vpn client 4.8 connects but cannot send or receive

Could you verify if DC user has opened UDP ports 500 and 4500 for his Internet connection???

Blocked port UDP 4500 brings problems when NAT is used

M.

New Member

Re: Cisco vpn client 4.8 connects but cannot send or receive

Figured it out thanks for the help but turns out was an incompatability with the dell wireless network adapter that was causing the problem not with the vpn client or config. THanks again for the feedback and help.

New Member

Re: Cisco vpn client 4.8 connects but cannot send or receive

Check the MTU size on the client. I have seen the same problem using the VPN 3030. Changing the Client MTU 1300 has fix the problems for use.

New Member

Re: Cisco vpn client 4.8 connects but cannot send or receive

I saw the same behavior with connectivity to ASA 5540 with Cisco client 4.8. I could login with client but could not connect to anything. 'show crypto ipsec sa' showed my security association with packets decrypted, but none encrypted. A static route for the ip address pool was present on the inside. When I changed my MTU setting to 1300 for my 'local area connection' through the client MTU application (program files > cisco vpn client > Set MTU) I was able to connect to stuff on the inside of the ASA. Very strange as earlier in the day from this same PC and using same LAN connection I had been able to login and access stuff on the inside just fine. I intend to do more research into this, but does anyone have any comment on this? I'm very puzzled.

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