Tech Support > Computer Hardware > Routers > IPSEC: reserved not zero on payload message when connecting site-to-site
IPSEC: reserved not zero on payload message when connecting site-to-site
Posted by Arjan on October 12th, 2005


I finally managed to implement a Site-to-Site tunnel using IPSEC
between ISA back-to-back on one site and and a PIX on the other.

When testing I noticed that it takes some time to establish the
connection. Debug showed the following message several times during
negotiating:
"ISAKMP: reserved not zero on payload 8!"
"ISAKMP: malformed payload"

This message comes up serveral times and then finally the connection
starts working.
Cisco stated that this message means that the shared key does not
match however, I cheked this (of course) and still the message comes
up. Both in the end the tunnel comes up and traffic is allowed and
works.

The problem here is the relative long time needed to establish the
tunnel causes time-out problems on applications (RDP e.g.)

I already tried to disable PFS and also checked IKE timers etc.

Does anyone know the solution for this.

Posted by Merv on October 12th, 2005




Does the hash algorihmn configured for each peer match?

Posted by Arjan on October 13th, 2005


On 12 Oct 2005 16:17:01 -0700, "Merv" <merv.hrabi@rogers.com> wrote:

meaning ESP-DES-MD5 for stage one and two? Yes they do, however PIX
also has policy for ESP-DES-SHA that is not used at the moment.