I got a CAW7740N Router behind a Motorola SBV5121E Modem and from time to time the connection is very slow. Every time I figured out that there are similar entries in the routers security log:
08/12/2011 22:03:44 DHCP Client: [WAN]Receive Ack from xx.xx.xx.xx,Lease time=3600 08/12/2011 22:03:44 DHCP Client: [WAN]Send Request, Request IP=xx.xx.xx.xx
It usually occurs with web-application-like websites like Facebook or Flickr and often if I load more than one page very quickly simultaneously. I think that the slow down doesn't occur if I turn off the routers firewall. Or could the old Motorola Modem be a problem?
Here are the security settings:
Stateful Packet Inspection: SPI and Anti-DoS firewall protection: on RIP defect: off Discard Ping To WAN Interface: on Stateful Packet Inspection: Packet Fragmentation: on TCP Connection: on UDP Session: on FTP Service: on H.323 Service: on TFTP Service: on Connection Policy: Fragmentation half-open wait: 10sec TCP SYN wait: 30sec TCP FIN wait: 5sec TCP connection idle timeout: 3600sec UDP session idle timeout: 30sec H.323 data channel idle timeout: 180sec DoS Detect Criteria: Total incomplete TCP/UDP sessions HIGH: 300 session Total incomplete TCP/UDP sessions LOW: 250 session Incomplete TCP/UDP sessions (per min) HIGH: 250 session Incomplete TCP/UDP sessions (per min) LOW: 200 session Maximum incomplete TCP/UDP sessions number from same host: 50 Incomplete TCP/UDP sessions detect sensitive time period: 500msec Maximum half-open fragmentation packet number from same host: 150 Half-open fragmentation detect sensitive time period: 10000msec Flooding cracker block time: 300sec