Passing IPSec traffic through VLAN trunks

I have a Cisco 3750 and 2950 switch in my network. Trunking is enabled on the link that connects the 2950 to the 3750 switch with encap as dot1q.

One VLAN, viz. VLAN4, is configured in the 3750 with IP address as The IP address of the default VLAN (VLAN 1) is and a DHCP server resides in this VLAN which has a scope created ( -; Mask; Router: for VLAN4. IP address of DHCP server is

Interface VLAN4 has been configured with the command "ip helper-address" and the members of the VLAN4, which are connected to 3750 as well as in 2950, gets an address from the range - without any problem.

I have a Cisco PIX 515E firewall whose "inside" interface ( IP address: ) is connected to a port in the 3750 which is member of VLAN4. One IPSec VPN tunnel is created
with one of my clients, though the PIX firewall. The target IP address in client location is Following route is added in the 3750:

ip route

I have connected one PC in 3750 and one in 2950 and they are member of VLAN4. The PC in 3750 gets an address of and the one in 2950 gets The default gateway they get, as defined in the scope, is

The PC connected to 3750 can ping the address over the VPN but the PC in 2950 cannot.

What could be the problem ?
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

bi directional traffic on the fw or uni?
mitra_amAuthor Commented:
Problem solved. Allowed all the VLANs through the trunks.
PAQed with points refunded (100)

EE Admin

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.