We have a network as shown in the picture:
(Internet)
|
| PPP
|
+---------------------+
| Firewall |
| Debian Linux |
| Kernel 2.4.0 |
| Sendmail 8.11.2 |
| Qpopper 3.1 |
+---------------------+
|
+---------------------+ |
| SERVER I |--------(Subnet 172.25.0.0) |
| Debian Linux |--------(Subnet 172.26.0.0)------+
| Kernel 2.2.18 |--------(Subnet 172.27.0.0)
| |--------(Subnet 172.28.0.0)
+---------------------+
|
| PPP
|
+---------------------+
| SERVER II |--------(Subnet 172.16.0.0)
| Debian Linux |--------(Subnet 172.17.0.0)
| Kernel 2.2.18 |--------(Subnet 172.18.0.0)
+----------------------+
All the users have accounts in the Firewall and can get E-mail via Qpopper (POP3).
When I used kernel 2.2.18 (and IPChains) in the Firewall everything worked fine.
After upgrading Firewall kernel to 2.4.0 (and IPTables) we'd gotten into troubble. Any Windows box connected to the SERVER II (behind the PPP link) can send E-mail via Sendmail, and get E-mail not more then 1 - 2 KB in size. If a message was more then 1 - 2 KB in size, the process had been begining and freezing after sending very small part of the message. IPTraf revieled that Firewall was sending one packet per minutes or two. All the boxes connected to the SERVER I work as they did before upgrading.
Can anybody tell me what is the cause of the problem, or give a piece of advice where to seek for it.
I attach an extraction from mail.log, it is rather huge, so I gzipped it.
Thank you, Mikhail.
Attachment:
mail.log.gz
Description: GNU Zip compressed data