# Numerous syncache errors



## justme (Feb 19, 2009)

Hi,

I have been seeing a LOT of syncache related errors below since I started using FreeBSD 7:

TCP: [202.110.190.37]:41630 to [74.86.152.232]:25 tcpflags 0x4<RST>; syncache_chkrst: Spurious RST without matching syncache entry (possibly syncookie only), segment ignored
TCP: [88.45.227.130]:29905 to [74.86.152.232]:25 tcpflags 0x4<RST>; syncache_chkrst: Spurious RST without matching syncache entry (possibly syncookie only), segment ignored
TCP: [69.1.128.149]:16263 to [74.86.152.232]:25 tcpflags 0x2<SYN>; syncache_add: Received duplicate SYN, resetting timer and retransmitting SYN|ACK
TCP: [207.44.196.79]:49715 to [74.86.158.240]:25 tcpflags 0x4<RST>; syncache_chkrst: Spurious RST without matching syncache entry (possibly syncookie only), segment ignored
TCP: [69.129.159.146]:46401 to [74.86.152.232]:25 tcpflags 0x2<SYN>; syncache_add: Received duplicate SYN, resetting timer and retransmitting SYN|ACK
TCP: [74.55.8.26]:35326 to [74.86.152.232]:25 tcpflags 0x4<RST>; syncache_chkrst: Spurious RST without matching syncache entry (possibly syncookie only), segment ignored
TCP: [69.129.159.146]:46401 to [74.86.152.232]:25; syncache_timer: Response timeout, retransmitting (1) SYN|ACK
TCP: [75.126.133.184]:443 to [74.86.204.27]:58622 tcpflags 0x18<PUSH,ACK>; tcp_do_segment: FIN_WAIT_1: Received 37 bytes of data after socket was closed, sending RST and removing tcpcb
TCP: [66.72.74.132]:50507 to [74.86.158.240]:80 tcpflags 0x10<ACK>; syncache_expand: Segment failed SYNCOOKIE authentication, segment rejected (probably spoofed)
TCP: [194.242.114.33]:38187 to [74.86.152.232]:25 tcpflags 0x18<PUSH,ACK>; syncache_expand: Segment failed SYNCOOKIE authentication, segment rejected (probably spoofed)

Could someone tell me if these are serious errors and how to correct them? Thanks

Tom


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