sync,sync && ack 不停的重发

客户端:
node2:
node2:/root#hostname 
node2
node2:/root#netstat -na | grep 8080
node2:/root#


服务端:

node1:/root#netstat -na | grep 8080
tcp        0      0 192.168.137.2:8080          0.0.0.0:*                   LISTEN 


iptables -I INPUT -s 192.168.137.2 -j DROP 丢弃 服务端过来的数据包:

node2:/root#telnet 192.168.137.3 8080
Trying 192.168.137.3...
telnet: connect to address 192.168.137.3: Connection refused
node2:/root#telnet 192.168.137.2 8080
Trying 192.168.137.2...



客户端:
node2:/root#netstat -na | grep 8080
tcp        0      1 192.168.137.3:25192         192.168.137.2:8080          SYN_SENT    
node2:/root#


服务端:

node1:/root#netstat -na | grep 8080
tcp        0      0 192.168.137.2:8080          0.0.0.0:*                   LISTEN      
tcp        0      0 192.168.137.2:8080          192.168.137.3:25192         SYN_RECV   


node1:/root#set -o vi
node1:/root#tcpdump -S -i eth1 '((tcp) and  (port 8080) and (host 192.168.137.3) )' 
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth1, link-type EN10MB (Ethernet), capture size 65535 bytes
03:11:48.050834 IP node2.25124 > node1.webcache: Flags [S], seq 3256531200, win 14600, options [mss 1460,sackOK,TS val 507444343 ecr 0,nop,wscale 7], length 0
03:11:48.050870 IP node1.webcache > node2.25124: Flags [S.], seq 2583569080, ack 3256531201, win 14480, options [mss 1460,sackOK,TS val 3917258 ecr 507444343,nop,wscale 6], length 0
03:11:49.050559 IP node1.webcache > node2.25124: Flags [S.], seq 2583569080, ack 3256531201, win 14480, options [mss 1460,sackOK,TS val 3918258 ecr 507444343,nop,wscale 6], length 0
03:11:49.050596 IP node2.25124 > node1.webcache: Flags [S], seq 3256531200, win 14600, options [mss 1460,sackOK,TS val 507445343 ecr 0,nop,wscale 7], length 0
03:11:49.050604 IP node1.webcache > node2.25124: Flags [S.], seq 2583569080, ack 3256531201, win 14480, options [mss 1460,sackOK,TS val 3918258 ecr 507444343,nop,wscale 6], length 0
03:11:51.051836 IP node2.25124 > node1.webcache: Flags [S], seq 3256531200, win 14600, options [mss 1460,sackOK,TS val 507447344 ecr 0,nop,wscale 7], length 0
03:11:51.051892 IP node1.webcache > node2.25124: Flags [S.], seq 2583569080, ack 3256531201, win 14480, options [mss 1460,sackOK,TS val 3920259 ecr 507444343,nop,wscale 6], length 0
03:11:51.250822 IP node1.webcache > node2.25124: Flags [S.], seq 2583569080, ack 3256531201, win 14480, options [mss 1460,sackOK,TS val 3920458 ecr 507444343,nop,wscale 6], length 0



03:11:55.051302 IP node2.25124 > node1.webcache: Flags [S], seq 3256531200, win 14600, options [mss 1460,sackOK,TS val 507451344 ecr 0,nop,wscale 7], length 0
03:11:55.051358 IP node1.webcache > node2.25124: Flags [S.], seq 2583569080, ack 3256531201, win 14480, options [mss 1460,sackOK,TS val 3924258 ecr 507444343,nop,wscale 6], length 0
03:11:55.455673 IP node1.webcache > node2.25124: Flags [S.], seq 2583569080, ack 3256531201, win 14480, options [mss 1460,sackOK,TS val 3924663 ecr 507444343,nop,wscale 6], length 0
03:12:03.051635 IP node2.25124 > node1.webcache: Flags [S], seq 3256531200, win 14600, options [mss 1460,sackOK,TS val 507459344 ecr 0,nop,wscale 7], length 0
03:12:03.051673 IP node1.webcache > node2.25124: Flags [S.], seq 2583569080, ack 3256531201, win 14480, options [mss 1460,sackOK,TS val 3932259 ecr 507444343,nop,wscale 6], length 0
03:12:03.486804 IP node1.webcache > node2.25124: Flags [S.], seq 2583569080, ack 3256531201, win 14480, options [mss 1460,sackOK,TS val 3932694 ecr 507444343,nop,wscale 6], length 0
03:12:19.055497 IP node2.25124 > node1.webcache: Flags [S], seq 3256531200, win 14600, options [mss 1460,sackOK,TS val 507475348 ecr 0,nop,wscale 7], length 0
03:12:19.055539 IP node1.webcache > node2.25124: Flags [S.], seq 2583569080, ack 3256531201, win 14480, options [mss 1460,sackOK,TS val 3948262 ecr 507444343,nop,wscale 6], length 0
03:12:19.525843 IP node1.webcache > node2.25124: Flags [S.], seq 2583569080, ack 3256531201, win 14480, options [mss 1460,sackOK,TS val 3948733 ecr 507444343,nop,wscale 6], length 0




会不停的SYN和SYNC,ACK 

原文地址:https://www.cnblogs.com/hzcya1995/p/13348469.html