注意这里的描述，并不是端口没有开启服务，而是没有开启UDP服务，如果开启了TCP服务，照样也会回port unreachable。...= NULL)，就回复icmp destination unreachable（这就是服务器没有对应端口接受UDP的处理流程），函数非常简单 所以作为服务器，收到一个目的端口并未监听的报文，直接回复端口不可达...实际上icmp_rcv函数最重要的是 它调用了：icmp_pointers[icmph->type].handler(skb); handler = icmp_unreach icmp_unreach函数最终的一步...unreachable\n"); } } //方法2 #elif 0 ret = connect(fd, (const struct sockaddr *) &(server_addr),...unreachable\n"); } } #endif close(fd); return 0; } 如果对你有用，请打赏一元哦：http://www.mrpre.com/ 发布者
, ICMP_HOST_UNREACHABLE, ICMP_PROTOCAL_UNREACHABLE, ICMP_PORT_UNREACHABLE, ICMP_FRAGMETATION_NEEDED_AND_DF_SET...case ICMP_PORT_UNREACHABLE: //错误数据格式:IP包头和8字节内容 //获取协议类型 byte protocol...; } } 我们看到，Destination UnReachable错误对应的type是3，但它有对应不同的code值，这些值对应不同情形的unreachable错误，代码里的枚举类ICMP_ERROR_MSG_CODE...对应不同code值，在上面实现中，我们暂时只处理code值是3的情况，也就是处理port unreachable这种情形。...从上图看出该数据包的type和code都是3，表示它包含Destination UnReachable错误信息，具体错误类型为port unreachable。
no-route packet-too-big parameter-problem port-unreachable precedence-cutoff protocol-unreachable redirect...From 192.168.1.181 icmp_seq=1 Destination Port Unreachable ^C --- 192.168.1.181 ping statistics --- 1...From 192.168.1.181 icmp_seq=1 Destination Port Unreachable ^C --- 192.168.1.181 ping statistics --- 1...no-route packet-too-big parameter-problem port-unreachable precedence-cutoff protocol-unreachable redirect...unknown-option [root@ds1 ~]# firewall-cmd --info-icmptype=destination-unreachable destination-unreachable
172.16.0.46 udp port 8888 unreachable, length 37 17:01:17.326145 IP 172.16.0.46 > 172.16.0.62: ICMP...172.16.0.46 udp port 8888 unreachable, length 37 17:01:17.927480 IP 172.16.0.46 > 172.16.0.62: ICMP 172.16.0.46...udp port 8888 unreachable, length 37 17:01:18.489560 IP 172.16.0.46 > 172.16.0.62: ICMP 172.16.0.46...Unreachable From 172.16.0.46 icmp_seq=3 Destination Host Unreachable From 172.16.0.46 icmp_seq=4 Destination...Host Unreachable From 172.16.0.46 icmp_seq=5 Destination Host Unreachable From 172.16.0.46 icmp_seq=
│ ├── no-route.xml │ ├── packet-too-big.xml │ ├── parameter-problem.xml │ ├── port-unreachable.xml...port,ip hash:ip,port,net hash:mac hash:net hash:net,iface hash:net,net hash:net,port hash:net,port,net...用来管理定义 icmp 的响应类型 [root@ds1 ~]# firewall-cmd --get-icmptypes address-unreachable bad-header communication-prohibited...port-unreachable precedence-cutoff protocol-unreachable redirect required-option-missing router-advertisement...rw-r--r--. 1 root root 225 Apr 11 04:52 parameter-problem.xml -rw-r--r--. 1 root root 233 Apr 11 04:52 port-unreachable.xml
From 192.168.10.10 icmp_seq=1 Destination Port Unreachable From 192.168.10.10 icmp_seq=2 Destination...Port Unreachable From 192.168.10.10 icmp_seq=3 Destination Port Unreachable From 192.168.10.10 icmp_seq...anywhere tcp dpt:italk reject-with icmp-port-unreachable ACCEPT tcp -- 192.168.10.0/24 anywhere tcp...dpt:ssh REJECT tcp -- anywhere anywhere tcp dpt:ssh reject-with icmp-port-unreachable ………………省略部分输出信息…...anywhere tcp dpt:italk reject-with icmp-port-unreachable ACCEPT tcp -- 192.168.10.0/24 anywhere tcp
From 192.168.3.1 icmp_seq=1 Destination Host Unreachable From 192.168.3.1 icmp_seq=2 Destination Host...Unreachable From 192.168.3.1 icmp_seq=3 Destination Host Unreachable From 192.168.3.1 icmp_seq=4 Destination...From 192.168.3.1 icmp_seq=1 Destination Host Unreachable From 192.168.3.1 icmp_seq=2 Destination Host...Unreachable From 192.168.3.1 icmp_seq=3 Destination Host Unreachable From 192.168.3.1 icmp_seq=4 Destination...Unreachable From 192.168.2.11 icmp_seq=3 Destination Host Unreachable From 192.168.2.11 icmp_seq=4 Destination
= (11000 + 2) Private Const IP_DEST_HOST_UNREACHABLE = (11000 + 3) Private Const IP_DEST_PROT_UNREACHABLE...= (11000 + 4) Private Const IP_DEST_PORT_UNREACHABLE = (11000 + 5) Private Const IP_NO_RESOURCES = (...: msg = "ip dest net unreachable" Case IP_DEST_HOST_UNREACHABLE: msg = "ip dest host unreachable..." Case IP_DEST_PROT_UNREACHABLE: msg = "ip dest prot unreachable" Case IP_DEST_PORT_UNREACHABLE...: msg = "ip dest port unreachable" Case IP_NO_RESOURCES: msg = "ip no resources"
#define ICMP_DEST_UNREACH 3 /* Destination Unreachable */#endif#ifndef ICMP_SOURCE_QUENCH...*/#ifndef ICMP_NET_UNREACH#define ICMP_NET_UNREACH 0 /* Network Unreachable */#...endif#ifndef ICMP_HOST_UNREACH#define ICMP_HOST_UNREACH 1 /* Host Unreachable...*/#endif#ifndef ICMP_PORT_UNREACH#define ICMP_PORT_UNREACH 3 /* Port Unreachable...4 /* bad port */#define ICMP6_DST_UNREACH_FAILEDPOLICY 5 /* Source address failed ingress/egress
code= port-unreachable chksum= 0x9e72 unused= 0 ###[ IP in ICMP ]### version...Port Unreachable from ip=172.16.36.132 name=UNKNOWN status=0 port=2792 seq=0 ICMP Port Unreachable...from ip=172.16.36.132 name=UNKNOWN status=0 port=2793 seq=1 ICMP Port Unreachable from ip=172.16.36.132...name=UNKNOWN status=0 port=2794 seq=2 ^F ICMP Port Unreachable from ip=172.16.36.132 name=UNKNOWN...mode set, 28 headers + 0 data bytes ICMP Port Unreachable from ip=172.16.36.135 HPING 172.16.36.136
s2gamebbs Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = s2gamebbs.test.com)(PORT...s2gamebbs.cyou.com (10.129.128.57) 56(84) bytes of data. 64 bytes from s2gamebbs.test.com (10.129.128.57): icmp_seq...From 10.129.128.57 icmp_seq=1 Destination Port Unreachable From 10.129.128.57 icmp_seq=2 Destination...Port Unreachable 如此一来，这个问题就有趣了，我对比了如下的几种测试场景。...-j ACCEPT -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -j REJECT --reject-with icmp-port-unreachable
当TTL等于1时，路由器便丢弃该包，并返回一ICMP Time Exceeded报文给源端。当目的地收到UDP报文，由于该端口上没有运行应用程序，返回ICMP Port Unreachable报文。...什么是 ICMP Port Unreachable错误报文，当主机收到此报文后有什么意义？...答: ICMP协议定义了多个错误报告控制报文，其中:Port Unreachable: Type=03,Code=03, 意义为 "If, in the destination host, the IP..., the destination host may send a port unreachable message to the source host."...即意思是当主机收到ICMP Port Unreachable，知道目的端没有打开此端口，应停止发送或者改变发送数据的目的端口。 6. 怎么判定Traceorute 的成功、失败？
rich rules: [root@localhost ~]# firewall-cmd --get-icmptypes #显示预定义的ICMP...类型 address-unreachable bad-header communication-prohibited destination-unreachable echo-reply...no-route packet-too-big parameter-problem port-unreachable precedence-cutoff protocol-unreachable...示例如下： [root@localhost services]# firewall-cmd --zone=internal --add-port=443/tcp #在internal...区域打开443/tcp端口 success [root@localhost services]# firewall-cmd --zone=internal --remove-port
Host Unreachable from 192.168.50.128 for ICMP Echo sent to 192.168.50.3 ICMP Host Unreachable from 192.168.50.128...for ICMP Echo sent to 192.168.50.3 ICMP Host Unreachable from 192.168.50.128 for ICMP Echo sent to 192.168.50.3...ICMP Host Unreachable from 192.168.50.128 for ICMP Echo sent to 192.168.50.3 192.168.50.3 is unreachable...192.168.50.4 is unreachable 192.168.50.5 is unreachable 5 targets 2 alive 3 unreachable...--arp -tr,--traceroute 路由跟踪模式（仅能和tcp、udp、icmp模式一起使用） -p, --dest-port 目标端口 -g, --source-port 源端口 --seq
: rich rules: [root@localhost ~]# firewall-cmd --get-icmptypes #显示预定义的ICMP类型 address-unreachable...no-route packet-too-big parameter-problem port-unreachable precedence-cutoff protocol-unreachable redirect...示例如下： [root@localhost services]# firewall-cmd --zone=internal --add-port=443/tcp #在internal区域打开443/...tcp端口 success [root@localhost services]# firewall-cmd --zone=internal --remove-port=443/tcp #在internal...-runtime-to-permanent success 直接配置为永久性规则，须带--permanent选项，如下： [root@localhost /]# firewall-cmd --add-icmp-block
包 触发点: ttl递增,icmp超时 icmp echo reply 注: 触发点都是根据ttl超时来检测 参考 项 traceroute tracert 使用协议 udp+2种icmp(ttl+端口不可达...) 仅2种icmp(ttl+icmp reply) 最终判别 端口不可达 ICMP Echo Reply 探测包都有唯一的标识号 UDP数据包使用递增的目标端口号(33434) ICMP使用seq识别...traceroute原理:UDP+icmp(icmp ttl超时/icmp端口不可达) tcp&udp扫描原理 1....直至目标地址收到探测数据包，并返回端口不可达通知（ICMP Port Unreachable）； 7. 当源地址收到ICMP Port Unreachable包时停止traceroute。...特点: 可见,这类icmp不是成双出现的, 它和ping的icmp一来一去不一样.
--显示预定义的ICMP类型--> address-unreachable bad-header communication-prohibited destination-unreachable echo-reply...no-route packet-too-big parameter-problem port-unreachable precedence-cutoff protocol-unreachable redirect...>]/：删除指定区域已设置的允许访问的端口号（包括协议名）； [–zone=] –list-icmp-blocaks：显示指定区域内拒绝访问的所有ICMP类型； [–zone...=] –add-icmp-block=：为指定区域设置拒绝访问的某项ICMP类型； [–zone=] –remove-icmp-block=<icmptype...示例如下： [root@centos01 ~]# firewall-cmd --zone=internal --add-port=443/tcp <!
1 REJECT tcp -- 192.168.1.20 0.0.0.0/0 tcp dpt:80 reject-with icmp-port-unreachable...2 REJECT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:8888 reject-with icmp-port-unreachable...1 REJECT tcp -- 192.168.1.20 0.0.0.0/0 tcp dpt:80 reject-with icmp-port-unreachable...2 REJECT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:8888 reject-with icmp-port-unreachable...5 REJECT udp -- 0.0.0.0/0 0.0.0.0/0 udp dpts:1000:2000 reject-with icmp-port-unreachable
")) 60.205.177.106 is unreachable 60.205.177.108 is unreachable 60.205.177.107 is unreachable 60.205.177.111...is unreachable 60.205.177.125 is unreachable 60.205.177.172 is unreachable 60.205.177.191 is unreachable...60.205.177.203 is unreachable 60.205.177.224 is unreachable 60.205.177.242 is unreachable 60.205.177.244...payload get='GET / HTTP/1.0\n\n' #设置目的地址和源地址 ip=IP(src="192.168.2.53",dst="60.205.177.168") # 定义一个随机源端口 port...=RandNum(1024,65535) # 构建SYN的包 SYN=ip/TCP(sport=port, dport=80, flags="S", seq=42) # 发送SYN并接收服务器响应（SYN
注意family 是AF_PACKET，这样就能监测所有输入和输出的数据包，而且不仅限于IP包（tcp/udp/icmp），如arp/rarp 包也可以监测，并且数据包还包含以太网头部。...2、Tcp syn port scan TCP 三次握手就不说了，端口扫描过程如下： 1. Send a Syn packet to a port A 2....Syn+Ack reply means the port is open , Rst packet means port is closed , and otherwise it might be inaccessible...Error message : %s \n" , errno , strerror(errno)); exit(0); } for(port = 1 ; port < 100 ; port++)...4、ICMP ping flood 实际上跟SYN flood 类似的道理，不过发送的是icmp 包，即自己封装icmp 头部 //Raw socket - if you use IPPROTO_ICMP
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