Suddenly not forwarding and no who-has reply

[Xpertech]

I have a 4.2 dual-nic server that has been working fine but suddenly stopped forwarding. Any help is appreciated.

One nic has a private address and connects directly to an NT server. The other nic has a public address and connects to our router. From the freeBSD server I can ping out of both nics but I can’t ping through the server. I am using ipsec. I have several freeBSD boxes at other sites that communicate directly to my freeBSD server. They can ping the server but cannot get through to the NT box. Below is a brief diagram and the tcpdump I get from the private nic when I try to ping the nt server from a remote freeBSD system:

Diagram:

NT server (10.10.1.2)
|
freeBSD server private NIC (10.10.1.1) <-- tcpdump
freeBSD server public NIC
|
ipsec tunnel
|
Remote freeBSD public NIC
Remote freeBSD private NIC (10.10.26.1)

pinging 10.10.1.1 from 10.10.26.1 is successful
pinging 10.10.1.2 from 10.10.26.1 fails


# tcpdump -i fxp1
tcpdump: listening on fxp1
12:42:48.551848 10.10.26.1 > 10.10.1.2: icmp: echo request
12:42:49.560074 10.10.26.1 > 10.10.1.2: icmp: echo request
12:42:49.560296 arp who-has 10.10.26.1 tell 10.10.1.2
12:42:50.573547 10.10.26.1 > 10.10.1.2: icmp: echo request
12:42:50.573689 arp who-has 10.10.26.1 tell 10.10.1.2
12:42:51.583260 10.10.26.1 > 10.10.1.2: icmp: echo request
12:42:51.583406 arp who-has 10.10.26.1 tell 10.10.1.2
12:42:52.589651 10.10.26.1 > 10.10.1.2: icmp: echo request
12:42:53.601643 10.10.26.1 > 10.10.1.2: icmp: echo request
12:42:53.601782 arp who-has 10.10.26.1 tell 10.10.1.2