Even after running
iptables -A INPUT -p icmp -m icmp --icmp-type 3 -j DROP
I keep getting ICMP type 3 code 13 packets on tcpdump. when I run
tcpdump icmp, I get messages like:
19:41:31.923630 IP NAMESOURCE > MY_NAME: ICMP net IP_SOURCE unreachable, length 76
My question is, How can I get rid of this packets?
Btw, I'm getting this packets from multiple sources, which leads me to think this might be some kind of (D)DoS. But I'm not sure which role I'm playing on this.
Also, snort keeps giving alerts:
[**] [1:485:4] ICMP Destination Unreachable Communication Administratively Prohibited [**] [Classification: Misc activity] [Priority: 3] 05/02-19:44:20.171298 SOURCE_IP -> MY_IP ICMP TTL:238 TOS:0x0 ID:13584 IpLen:20 DgmLen:56 Type:3 Code:13 DESTINATION UNREACHABLE: ADMINISTRATIVELY PROHIBITED, PACKET FILTERED ** ORIGINAL DATAGRAM DUMP: MY_IP:47541 -> SOURCE_IP:8080 TCP TTL:47 TOS:0x0 ID:22750 IpLen:20 DgmLen:60 DF Seq: 0x5EB7CF7A ** END OF DUMP